Merge pull request #127 from benbjohnson/nested-keys

Add nested buckets.

35 files changed, 2054 insertions, 1519 deletions

diff --git a/Makefile b/Makefile
index 1302aed..cb44a12 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,7 @@ cloc:
 	@cloc --not-match-f='Makefile|_test.go' .
 
 cover: fmt
-	go test -coverprofile=$(COVERPROFILE) -test.run=$(TEST) .
+	go test -coverprofile=$(COVERPROFILE) -test.run=$(TEST) $(COVERFLAG) .
 	go tool cover -html=$(COVERPROFILE)
 	rm $(COVERPROFILE)
 
@@ -47,6 +47,6 @@ test: fmt errcheck
 	@echo ""
 	@echo ""
 	@echo "=== RACE DETECTOR ==="
-	@go test -v -race -test.run=Parallel
+	@go test -v -race -test.run="TestSimulate_(100op|1000op|10000op)"
 
 .PHONY: bench cloc cover cpuprofile fmt memprofile test
diff --git a/bolt_test.go b/bolt_test.go
new file mode 100644
index 0000000..bbf00f5
--- /dev/null
+++ b/bolt_test.go
@@ -0,0 +1,327 @@
+package bolt
+
+import (
+	"bytes"
+	"fmt"
+	"math/rand"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSimulate_1op_1p(t *testing.T)     { testSimulate(t, 100, 1) }
+func TestSimulate_10op_1p(t *testing.T)    { testSimulate(t, 10, 1) }
+func TestSimulate_100op_1p(t *testing.T)   { testSimulate(t, 100, 1) }
+func TestSimulate_1000op_1p(t *testing.T)  { testSimulate(t, 1000, 1) }
+func TestSimulate_10000op_1p(t *testing.T) { testSimulate(t, 10000, 1) }
+
+func TestSimulate_10op_10p(t *testing.T)    { testSimulate(t, 10, 10) }
+func TestSimulate_100op_10p(t *testing.T)   { testSimulate(t, 100, 10) }
+func TestSimulate_1000op_10p(t *testing.T)  { testSimulate(t, 1000, 10) }
+func TestSimulate_10000op_10p(t *testing.T) { testSimulate(t, 10000, 10) }
+
+func TestSimulate_100op_100p(t *testing.T)   { testSimulate(t, 100, 100) }
+func TestSimulate_1000op_100p(t *testing.T)  { testSimulate(t, 1000, 100) }
+func TestSimulate_10000op_100p(t *testing.T) { testSimulate(t, 10000, 100) }
+
+func TestSimulate_10000op_1000p(t *testing.T) { testSimulate(t, 10000, 1000) }
+
+// Randomly generate operations on a given database with multiple clients to ensure consistency and thread safety.
+func testSimulate(t *testing.T, threadCount, parallelism int) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode.")
+	}
+
+	rand.Seed(int64(qseed))
+
+	// A list of operations that readers and writers can perform.
+	var readerHandlers = []simulateHandler{simulateGetHandler}
+	var writerHandlers = []simulateHandler{simulateGetHandler, simulatePutHandler}
+
+	var versions = make(map[txid]*QuickDB)
+	versions[1] = NewQuickDB()
+	withOpenDB(func(db *DB, path string) {
+		var mutex sync.Mutex
+
+		// Run n threads in parallel, each with their own operation.
+		var wg sync.WaitGroup
+		var threads = make(chan bool, parallelism)
+		var i int
+		for {
+			threads <- true
+			wg.Add(1)
+			writable := ((rand.Int() % 100) < 20) // 20% writers
+
+			// Choose an operation to execute.
+			var handler simulateHandler
+			if writable {
+				handler = writerHandlers[rand.Intn(len(writerHandlers))]
+			} else {
+				handler = readerHandlers[rand.Intn(len(readerHandlers))]
+			}
+
+			// Execute a thread for the given operation.
+			go func(writable bool, handler simulateHandler) {
+				defer wg.Done()
+
+				// Start transaction.
+				tx, err := db.Begin(writable)
+				if err != nil {
+					t.Fatal("tx begin: ", err)
+				}
+
+				// Obtain current state of the dataset.
+				mutex.Lock()
+				var qdb = versions[tx.id()]
+				if writable {
+					qdb = versions[tx.id()-1].Copy()
+				}
+				mutex.Unlock()
+
+				// Make sure we commit/rollback the tx at the end and update the state.
+				if writable {
+					defer func() {
+						mutex.Lock()
+						versions[tx.id()] = qdb
+						mutex.Unlock()
+
+						assert.NoError(t, tx.Commit())
+					}()
+				} else {
+					defer tx.Rollback()
+				}
+
+				// Ignore operation if we don't have data yet.
+				if qdb == nil {
+					return
+				}
+
+				// Execute handler.
+				handler(tx, qdb)
+
+				// Release a thread back to the scheduling loop.
+				<-threads
+			}(writable, handler)
+
+			i++
+			if i > threadCount {
+				break
+			}
+		}
+
+		// Wait until all threads are done.
+		wg.Wait()
+	})
+}
+
+type simulateHandler func(tx *Tx, qdb *QuickDB)
+
+// Retrieves a key from the database and verifies that it is what is expected.
+func simulateGetHandler(tx *Tx, qdb *QuickDB) {
+	// Randomly retrieve an existing exist.
+	keys := qdb.Rand()
+	if len(keys) == 0 {
+		return
+	}
+
+	// Retrieve root bucket.
+	b := tx.Bucket(keys[0])
+	if b == nil {
+		panic(fmt.Sprintf("bucket[0] expected: %v\n", keys[0]))
+	}
+
+	// Drill into nested buckets.
+	for _, key := range keys[1 : len(keys)-1] {
+		b = b.Bucket(key)
+		if b == nil {
+			panic(fmt.Sprintf("bucket[n] expected: %v -> %v\n", keys, key))
+		}
+	}
+
+	// Verify key/value on the final bucket.
+	expected := qdb.Get(keys)
+	actual := b.Get(keys[len(keys)-1])
+	if !bytes.Equal(actual, expected) {
+		fmt.Println("=== EXPECTED ===")
+		fmt.Println(expected)
+		fmt.Println("=== ACTUAL ===")
+		fmt.Println(actual)
+		fmt.Println("=== END ===")
+		panic("value mismatch")
+	}
+}
+
+// Inserts a key into the database.
+func simulatePutHandler(tx *Tx, qdb *QuickDB) {
+	keys, value := randKeys(), randValue()
+
+	// Retrieve root bucket.
+	b := tx.Bucket(keys[0])
+	if b == nil {
+		if err := tx.CreateBucket(keys[0]); err != nil {
+			panic("create bucket: " + err.Error())
+		}
+		b = tx.Bucket(keys[0])
+		if b == nil {
+			panic(fmt.Sprintf("bucket[0] nil: %v", keys[0]))
+		}
+	}
+
+	// Create nested buckets, if necessary.
+	for _, key := range keys[1 : len(keys)-1] {
+		child := b.Bucket(key)
+		if child != nil {
+			b = child
+		} else {
+			if err := b.CreateBucket(key); err != nil {
+				panic("create bucket: " + err.Error())
+			}
+			b = b.Bucket(key)
+		}
+	}
+
+	// Insert into database.
+	if err := b.Put(keys[len(keys)-1], value); err != nil {
+		panic("put: " + err.Error())
+	}
+
+	// Insert into in-memory database.
+	qdb.Put(keys, value)
+}
+
+// QuickDB is an in-memory database that replicates the functionality of the
+// Bolt DB type except that it is entirely in-memory. It is meant for testing
+// that the Bolt database is consistent.
+type QuickDB struct {
+	sync.RWMutex
+	m map[string]interface{}
+}
+
+// NewQuickDB returns an instance of QuickDB.
+func NewQuickDB() *QuickDB {
+	return &QuickDB{m: make(map[string]interface{})}
+}
+
+// Get retrieves the value at a key path.
+func (db *QuickDB) Get(keys [][]byte) []byte {
+	db.RLock()
+	defer db.RUnlock()
+
+	m := db.m
+	for _, key := range keys[:len(keys)-1] {
+		value := m[string(key)]
+		if value == nil {
+			return nil
+		}
+		switch value := value.(type) {
+		case map[string]interface{}:
+			m = value
+		case []byte:
+			return nil
+		}
+	}
+
+	// Only return if it's a simple value.
+	if value, ok := m[string(keys[len(keys)-1])].([]byte); ok {
+		return value
+	}
+	return nil
+}
+
+// Put inserts a value into a key path.
+func (db *QuickDB) Put(keys [][]byte, value []byte) {
+	db.Lock()
+	defer db.Unlock()
+
+	// Build buckets all the way down the key path.
+	m := db.m
+	for _, key := range keys[:len(keys)-1] {
+		if _, ok := m[string(key)].([]byte); ok {
+			return // Keypath intersects with a simple value. Do nothing.
+		}
+
+		if m[string(key)] == nil {
+			m[string(key)] = make(map[string]interface{})
+		}
+		m = m[string(key)].(map[string]interface{})
+	}
+
+	// Insert value into the last key.
+	m[string(keys[len(keys)-1])] = value
+}
+
+// Rand returns a random key path that points to a simple value.
+func (db *QuickDB) Rand() [][]byte {
+	db.RLock()
+	defer db.RUnlock()
+	if len(db.m) == 0 {
+		return nil
+	}
+	var keys [][]byte
+	db.rand(db.m, &keys)
+	return keys
+}
+
+func (db *QuickDB) rand(m map[string]interface{}, keys *[][]byte) {
+	i, index := 0, rand.Intn(len(m))
+	for k, v := range m {
+		if i == index {
+			*keys = append(*keys, []byte(k))
+			if v, ok := v.(map[string]interface{}); ok {
+				db.rand(v, keys)
+			}
+			return
+		}
+		i++
+	}
+	panic("quickdb rand: out-of-range")
+}
+
+// Copy copies the entire database.
+func (db *QuickDB) Copy() *QuickDB {
+	db.RLock()
+	defer db.RUnlock()
+	return &QuickDB{m: db.copy(db.m)}
+}
+
+func (db *QuickDB) copy(m map[string]interface{}) map[string]interface{} {
+	clone := make(map[string]interface{}, len(m))
+	for k, v := range m {
+		switch v := v.(type) {
+		case map[string]interface{}:
+			clone[k] = db.copy(v)
+		default:
+			clone[k] = v
+		}
+	}
+	return clone
+}
+
+func randKey() []byte {
+	var min, max = 1, 1024
+	n := rand.Intn(max-min) + min
+	b := make([]byte, n)
+	for i := 0; i < n; i++ {
+		b[i] = byte(rand.Intn(255))
+	}
+	return b
+}
+
+func randKeys() [][]byte {
+	var keys [][]byte
+	var count = rand.Intn(2) + 2
+	for i := 0; i < count; i++ {
+		keys = append(keys, randKey())
+	}
+	return keys
+}
+
+func randValue() []byte {
+	n := rand.Intn(8192)
+	b := make([]byte, n)
+	for i := 0; i < n; i++ {
+		b[i] = byte(rand.Intn(255))
+	}
+	return b
+}
diff --git a/bucket.go b/bucket.go
index 919d33b..c01d2c5 100644
--- a/bucket.go
+++ b/bucket.go
@@ -3,6 +3,9 @@ package bolt
 import (
 	"bytes"
 	"errors"
+	"fmt"
+	"sort"
+	"unsafe"
 )
 
 var (
@@ -16,14 +19,6 @@ var (
 	// ErrBucketNameRequired is returned when creating a bucket with a blank name.
 	ErrBucketNameRequired = errors.New("bucket name required")
 
-	// ErrBucketNameTooLarge is returned when creating a bucket with a name
-	// that is longer than MaxBucketNameSize.
-	ErrBucketNameTooLarge = errors.New("bucket name too large")
-
-	// ErrBucketNotWritable is returned when changing data on a bucket
-	// reference that was created from a read-only transaction.
-	ErrBucketNotWritable = errors.New("bucket not writable")
-
 	// ErrKeyRequired is returned when inserting a zero-length key.
 	ErrKeyRequired = errors.New("key required")
 
@@ -33,6 +28,11 @@ var (
 	// ErrValueTooLarge is returned when inserting a value that is larger than MaxValueSize.
 	ErrValueTooLarge = errors.New("value too large")
 
+	// ErrIncompatibleValue is returned when trying create or delete a bucket
+	// on an existing non-bucket key or when trying to create or delete a
+	// non-bucket key on an existing bucket key.
+	ErrIncompatibleValue = errors.New("incompatible value")
+
 	// ErrSequenceOverflow is returned when the next sequence number will be
 	// larger than the maximum integer size.
 	ErrSequenceOverflow = errors.New("sequence overflow")
@@ -41,8 +41,10 @@ var (
 // Bucket represents a collection of key/value pairs inside the database.
 type Bucket struct {
 	*bucket
-	name string
-	tx   *Tx
+	tx      *Tx
+	buckets map[string]*Bucket
+	nodes   map[pgid]*node
+	pending []*node
 }
 
 // bucket represents the on-file representation of a bucket.
@@ -51,9 +53,14 @@ type bucket struct {
 	sequence uint64
 }
 
-// Name returns the name of the bucket.
-func (b *Bucket) Name() string {
-	return b.name
+// newBucket returns a new bucket associated with a transaction.
+func newBucket(tx *Tx) Bucket {
+	var b = Bucket{tx: tx}
+	b.buckets = make(map[string]*Bucket)
+	if tx.writable {
+		b.nodes = make(map[pgid]*node)
+	}
+	return b
 }
 
 // Writable returns whether the bucket is writable.
@@ -70,17 +77,145 @@ func (b *Bucket) Cursor() *Cursor {
 
 	// Allocate and return a cursor.
 	return &Cursor{
-		tx:    b.tx,
-		root:  b.root,
-		stack: make([]elemRef, 0),
+		bucket: b,
+		stack:  make([]elemRef, 0),
+	}
+}
+
+// Bucket retrieves a nested bucket by name.
+// Returns nil if the bucket does not exist.
+func (b *Bucket) Bucket(name []byte) *Bucket {
+	if child := b.buckets[string(name)]; child != nil {
+		return child
+	}
+
+	// Move cursor to key.
+	c := b.Cursor()
+	k, v, flags := c.seek(name)
+
+	// Return nil if the key doesn't exist or it is not a bucket.
+	if !bytes.Equal(name, k) || (flags&bucketLeafFlag) == 0 {
+		return nil
+	}
+
+	// Otherwise create a bucket and cache it.
+	var child = newBucket(b.tx)
+	child.bucket = &bucket{}
+	*child.bucket = *(*bucket)(unsafe.Pointer(&v[0]))
+	b.buckets[string(name)] = &child
+
+	return &child
+}
+
+// CreateBucket creates a new bucket at the given key.
+// Returns an error if the key already exists, if the bucket name is blank, or if the bucket name is too long.
+func (b *Bucket) CreateBucket(key []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.tx.writable {
+		return ErrTxNotWritable
+	} else if len(key) == 0 {
+		return ErrBucketNameRequired
 	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if there is an existing key.
+	if bytes.Equal(key, k) {
+		if (flags & bucketLeafFlag) != 0 {
+			return ErrBucketExists
+		} else {
+			return ErrIncompatibleValue
+		}
+	}
+
+	// Create a blank root leaf page.
+	p, err := b.tx.allocate(1)
+	if err != nil {
+		return err
+	}
+	p.flags = leafPageFlag
+
+	// Insert key/value.
+	value := make([]byte, unsafe.Sizeof(bucket{}))
+	bucket := (*bucket)(unsafe.Pointer(&value[0]))
+	bucket.root = p.id
+
+	// Insert into node.
+	c.node().put(key, key, value, 0, bucketLeafFlag)
+
+	return nil
+}
+
+// CreateBucketIfNotExists creates a new bucket if it doesn't already exist.
+// Returns an error if the bucket name is blank, or if the bucket name is too long.
+func (b *Bucket) CreateBucketIfNotExists(key []byte) error {
+	err := b.CreateBucket(key)
+	if err != nil && err != ErrBucketExists {
+		return err
+	}
+	return nil
+}
+
+// DeleteBucket deletes a bucket at the given key.
+// Returns an error if the bucket does not exists, or if the key represents a non-bucket value.
+func (b *Bucket) DeleteBucket(key []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if bucket doesn't exist or is not a bucket.
+	if !bytes.Equal(key, k) {
+		return ErrBucketNotFound
+	} else if (flags & bucketLeafFlag) == 0 {
+		return ErrIncompatibleValue
+	}
+
+	// Recursively delete all child buckets.
+	child := b.Bucket(key)
+	err := child.ForEach(func(k, v []byte) error {
+		if v == nil {
+			if err := child.DeleteBucket(k); err != nil {
+				return fmt.Errorf("delete bucket: %s", err)
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	// Remove cached copy.
+	delete(b.buckets, string(key))
+
+	// Release all bucket pages to freelist.
+	b.tx.forEachPage(child.root, 0, func(p *page, _ int) {
+		b.tx.db.freelist.free(b.tx.id(), p)
+	})
+
+	// Delete the node if we have a matching key.
+	c.node().del(key)
+
+	return nil
 }
 
 // Get retrieves the value for a key in the bucket.
-// Returns a nil value if the key does not exist.
+// Returns a nil value if the key does not exist or if the key is a nested bucket.
 func (b *Bucket) Get(key []byte) []byte {
-	c := b.Cursor()
-	k, v := c.Seek(key)
+	k, v, flags := b.Cursor().seek(key)
+
+	// Return nil if this is a bucket.
+	if (flags & bucketLeafFlag) != 0 {
+		return nil
+	}
 
 	// If our target node isn't the same key as what's passed in then return nil.
 	if !bytes.Equal(key, k) {
@@ -96,11 +231,8 @@ func (b *Bucket) Put(key []byte, value []byte) error {
 	if b.tx.db == nil {
 		return ErrTxClosed
 	} else if !b.Writable() {
-		return ErrBucketNotWritable
-	}
-
-	// Validate the key and data size.
-	if len(key) == 0 {
+		return ErrTxNotWritable
+	} else if len(key) == 0 {
 		return ErrKeyRequired
 	} else if len(key) > MaxKeySize {
 		return ErrKeyTooLarge
@@ -110,10 +242,15 @@ func (b *Bucket) Put(key []byte, value []byte) error {
 
 	// Move cursor to correct position.
 	c := b.Cursor()
-	c.Seek(key)
+	k, _, flags := c.seek(key)
+
+	// Return an error if there is an existing key with a bucket value.
+	if bytes.Equal(key, k) && (flags&bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
 
-	// Insert the key/value.
-	c.node(b.tx).put(key, key, value, 0)
+	// Insert into node.
+	c.node().put(key, key, value, 0, 0)
 
 	return nil
 }
@@ -125,15 +262,20 @@ func (b *Bucket) Delete(key []byte) error {
 	if b.tx.db == nil {
 		return ErrTxClosed
 	} else if !b.Writable() {
-		return ErrBucketNotWritable
+		return ErrTxNotWritable
 	}
 
 	// Move cursor to correct position.
 	c := b.Cursor()
-	c.Seek(key)
+	_, _, flags := c.seek(key)
+
+	// Return an error if there is already existing bucket value.
+	if (flags & bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
 
 	// Delete the node if we have a matching key.
-	c.node(b.tx).del(key)
+	c.node().del(key)
 
 	return nil
 }
@@ -143,7 +285,7 @@ func (b *Bucket) NextSequence() (int, error) {
 	if b.tx.db == nil {
 		return 0, ErrTxClosed
 	} else if !b.Writable() {
-		return 0, ErrBucketNotWritable
+		return 0, ErrTxNotWritable
 	}
 
 	// Make sure next sequence number will not be larger than the maximum
@@ -194,6 +336,162 @@ func (b *Bucket) Stat() *BucketStat {
 	return s
 }
 
+// spill writes all the nodes for this bucket to dirty pages.
+func (b *Bucket) spill() error {
+	// Spill all child buckets first.
+	for name, child := range b.buckets {
+		if err := child.spill(); err != nil {
+			return err
+		}
+
+		// Update the child bucket header in this bucket.
+		value := make([]byte, unsafe.Sizeof(bucket{}))
+		bucket := (*bucket)(unsafe.Pointer(&value[0]))
+		*bucket = *child.bucket
+
+		// Update parent node.
+		c := b.Cursor()
+		k, _, flags := c.seek([]byte(name))
+		_assert(bytes.Equal([]byte(name), k), "misplaced bucket header: %x -> %x", []byte(name), k)
+		_assert(flags&bucketLeafFlag != 0, "unexpected bucket header flag: %x", flags)
+		c.node().put([]byte(name), []byte(name), value, 0, bucketLeafFlag)
+	}
+
+	// Ignore if there are no nodes to spill.
+	if len(b.nodes) == 0 {
+		return nil
+	}
+
+	// Sort nodes by highest depth first.
+	nodes := make(nodesByDepth, 0, len(b.nodes))
+	for _, n := range b.nodes {
+		nodes = append(nodes, n)
+	}
+	sort.Sort(nodes)
+
+	// Spill nodes by deepest first.
+	for i := 0; i < len(nodes); i++ {
+		n := nodes[i]
+
+		// Split nodes into appropriate sized nodes.
+		// The first node in this list will be a reference to n to preserve ancestry.
+		newNodes := n.split(b.tx.db.pageSize)
+		b.pending = newNodes
+
+		// If this is a root node that split then create a parent node.
+		if n.parent == nil && len(newNodes) > 1 {
+			n.parent = &node{bucket: b, isLeaf: false}
+			nodes = append(nodes, n.parent)
+		}
+
+		// Add node's page to the freelist.
+		if n.pgid > 0 {
+			b.tx.db.freelist.free(b.tx.id(), b.tx.page(n.pgid))
+		}
+
+		// Write nodes to dirty pages.
+		for i, newNode := range newNodes {
+			// Allocate contiguous space for the node.
+			p, err := b.tx.allocate((newNode.size() / b.tx.db.pageSize) + 1)
+			if err != nil {
+				return err
+			}
+
+			// Write the node to the page.
+			newNode.write(p)
+			newNode.pgid = p.id
+			newNode.parent = n.parent
+
+			// The first node should use the existing entry, other nodes are inserts.
+			var oldKey []byte
+			if i == 0 {
+				oldKey = n.key
+			} else {
+				oldKey = newNode.inodes[0].key
+			}
+
+			// Update the parent entry.
+			if newNode.parent != nil {
+				newNode.parent.put(oldKey, newNode.inodes[0].key, nil, newNode.pgid, 0)
+			}
+
+			// Update the statistics.
+			b.tx.stats.Spill++
+		}
+
+		b.pending = nil
+	}
+
+	// Clear out nodes now that they are all spilled.
+	b.nodes = make(map[pgid]*node)
+
+	// Update the root node for this bucket.
+	b.root = nodes[len(nodes)-1].pgid
+
+	return nil
+}
+
+// rebalance attempts to balance all nodes.
+func (b *Bucket) rebalance() {
+	for _, n := range b.nodes {
+		n.rebalance()
+	}
+	for _, child := range b.buckets {
+		child.rebalance()
+	}
+}
+
+// node creates a node from a page and associates it with a given parent.
+func (b *Bucket) node(pgid pgid, parent *node) *node {
+	_assert(b.nodes != nil, "nodes map expected")
+	// Retrieve node if it's already been created.
+	if n := b.nodes[pgid]; n != nil {
+		return n
+	}
+
+	// Otherwise create a branch and cache it.
+	n := &node{bucket: b, parent: parent}
+	if n.parent != nil {
+		n.depth = n.parent.depth + 1
+	}
+	n.read(b.tx.page(pgid))
+	b.nodes[pgid] = n
+
+	// Update statistics.
+	b.tx.stats.NodeCount++
+
+	return n
+}
+
+// dereference removes all references to the old mmap.
+func (b *Bucket) dereference() {
+	for _, n := range b.nodes {
+		n.dereference()
+	}
+
+	for _, n := range b.pending {
+		n.dereference()
+	}
+
+	for _, child := range b.buckets {
+		child.dereference()
+	}
+
+	// Update statistics
+	b.tx.stats.NodeDeref += len(b.nodes) + len(b.pending)
+}
+
+// pageNode returns the in-memory node, if it exists.
+// Otherwise returns the underlying page.
+func (b *Bucket) pageNode(id pgid) (*page, *node) {
+	if b.nodes != nil {
+		if n := b.nodes[id]; n != nil {
+			return nil, n
+		}
+	}
+	return b.tx.page(id), nil
+}
+
 // BucketStat represents stats on a bucket such as branch pages and leaf pages.
 type BucketStat struct {
 	BranchPageCount   int
@@ -202,9 +500,3 @@ type BucketStat struct {
 	KeyCount          int
 	MaxDepth          int
 }
-
-type bucketsByName []*Bucket
-
-func (s bucketsByName) Len() int           { return len(s) }
-func (s bucketsByName) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
-func (s bucketsByName) Less(i, j int) bool { return s[i].name < s[j].name }
diff --git a/bucket_test.go b/bucket_test.go
index c49a923..75cbbe8 100644
--- a/bucket_test.go
+++ b/bucket_test.go
@@ -14,11 +14,11 @@ import (
 )
 
 // Ensure that a bucket that gets a non-existent key returns nil.
-func TestBucketGetNonExistent(t *testing.T) {
+func TestBucket_Get_NonExistent(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			value := tx.Bucket("widgets").Get([]byte("foo"))
+			tx.CreateBucket([]byte("widgets"))
+			value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
 			assert.Nil(t, value)
 			return nil
 		})
@@ -26,11 +26,11 @@ func TestBucketGetNonExistent(t *testing.T) {
 }
 
 // Ensure that a bucket can read a value that is not flushed yet.
-func TestBucketGetFromNode(t *testing.T) {
+func TestBucket_Get_FromNode(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			b := tx.Bucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
 			b.Put([]byte("foo"), []byte("bar"))
 			value := b.Get([]byte("foo"))
 			assert.Equal(t, value, []byte("bar"))
@@ -39,84 +39,278 @@ func TestBucketGetFromNode(t *testing.T) {
 	})
 }
 
+// Ensure that a bucket retrieved via Get() returns a nil.
+func TestBucket_Get_IncompatibleValue(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).CreateBucket([]byte("foo")))
+			assert.Nil(t, tx.Bucket([]byte("widgets")).Get([]byte("foo")))
+			return nil
+		})
+	})
+}
+
 // Ensure that a bucket can write a key/value.
-func TestBucketPut(t *testing.T) {
+func TestBucket_Put(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			err := tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
+			tx.CreateBucket([]byte("widgets"))
+			err := tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
 			assert.NoError(t, err)
-			value := tx.Bucket("widgets").Get([]byte("foo"))
+			value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
 			assert.Equal(t, value, []byte("bar"))
 			return nil
 		})
 	})
 }
 
+// Ensure that a bucket can rewrite a key in the same transaction.
+func TestBucket_Put_Repeat(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			assert.NoError(t, b.Put([]byte("foo"), []byte("bar")))
+			assert.NoError(t, b.Put([]byte("foo"), []byte("baz")))
+			value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
+			assert.Equal(t, value, []byte("baz"))
+			return nil
+		})
+	})
+}
+
+// Ensure that a bucket can write a bunch of large values.
+func TestBucket_Put_Large(t *testing.T) {
+	var count = 100
+	var factor = 200
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			for i := 1; i < count; i++ {
+				assert.NoError(t, b.Put([]byte(strings.Repeat("0", i*factor)), []byte(strings.Repeat("X", (count-i)*factor))))
+			}
+			return nil
+		})
+		db.View(func(tx *Tx) error {
+			b := tx.Bucket([]byte("widgets"))
+			for i := 1; i < count; i++ {
+				value := b.Get([]byte(strings.Repeat("0", i*factor)))
+				assert.Equal(t, []byte(strings.Repeat("X", (count-i)*factor)), value)
+			}
+			return nil
+		})
+	})
+}
+
+// Ensure that a setting a value on a key with a bucket value returns an error.
+func TestBucket_Put_IncompatibleValue(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).CreateBucket([]byte("foo")))
+			assert.Equal(t, ErrIncompatibleValue, tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar")))
+			return nil
+		})
+	})
+}
+
+// Ensure that a setting a value while the transaction is closed returns an error.
+func TestBucket_Put_Closed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.Begin(true)
+		tx.CreateBucket([]byte("widgets"))
+		b := tx.Bucket([]byte("widgets"))
+		tx.Rollback()
+		assert.Equal(t, ErrTxClosed, b.Put([]byte("foo"), []byte("bar")))
+	})
+}
+
 // Ensure that setting a value on a read-only bucket returns an error.
-func TestBucketPutReadOnly(t *testing.T) {
+func TestBucket_Put_ReadOnly(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
 			return nil
 		})
 		db.View(func(tx *Tx) error {
-			b := tx.Bucket("widgets")
+			b := tx.Bucket([]byte("widgets"))
 			err := b.Put([]byte("foo"), []byte("bar"))
-			assert.Equal(t, err, ErrBucketNotWritable)
+			assert.Equal(t, err, ErrTxNotWritable)
 			return nil
 		})
 	})
 }
 
 // Ensure that a bucket can delete an existing key.
-func TestBucketDelete(t *testing.T) {
+func TestBucket_Delete(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
-			err := tx.Bucket("widgets").Delete([]byte("foo"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
+			err := tx.Bucket([]byte("widgets")).Delete([]byte("foo"))
 			assert.NoError(t, err)
-			value := tx.Bucket("widgets").Get([]byte("foo"))
+			value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
 			assert.Nil(t, value)
 			return nil
 		})
 	})
 }
 
+// Ensure that deleting a bucket using Delete() returns an error.
+func TestBucket_Delete_Bucket(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			assert.NoError(t, b.CreateBucket([]byte("foo")))
+			assert.Equal(t, ErrIncompatibleValue, b.Delete([]byte("foo")))
+			return nil
+		})
+	})
+}
+
 // Ensure that deleting a key on a read-only bucket returns an error.
-func TestBucketDeleteReadOnly(t *testing.T) {
+func TestBucket_Delete_ReadOnly(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
 			return nil
 		})
 		db.View(func(tx *Tx) error {
-			b := tx.Bucket("widgets")
+			b := tx.Bucket([]byte("widgets"))
 			err := b.Delete([]byte("foo"))
-			assert.Equal(t, err, ErrBucketNotWritable)
+			assert.Equal(t, err, ErrTxNotWritable)
+			return nil
+		})
+	})
+}
+
+// Ensure that a deleting value while the transaction is closed returns an error.
+func TestBucket_Delete_Closed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.Begin(true)
+		tx.CreateBucket([]byte("widgets"))
+		b := tx.Bucket([]byte("widgets"))
+		tx.Rollback()
+		assert.Equal(t, ErrTxClosed, b.Delete([]byte("foo")))
+	})
+}
+
+// Ensure that deleting a bucket causes nested buckets to be deleted.
+func TestBucket_DeleteBucket_Nested(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).CreateBucket([]byte("foo")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).Bucket([]byte("foo")).CreateBucket([]byte("bar")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).Bucket([]byte("foo")).Bucket([]byte("bar")).Put([]byte("baz"), []byte("bat")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).DeleteBucket([]byte("foo")))
+			return nil
+		})
+	})
+}
+
+// Ensure that deleting a bucket causes nested buckets to be deleted after they have been committed.
+func TestBucket_DeleteBucket_Nested2(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).CreateBucket([]byte("foo")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).Bucket([]byte("foo")).CreateBucket([]byte("bar")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).Bucket([]byte("foo")).Bucket([]byte("bar")).Put([]byte("baz"), []byte("bat")))
+			return nil
+		})
+		db.Update(func(tx *Tx) error {
+			assert.NotNil(t, tx.Bucket([]byte("widgets")))
+			assert.NotNil(t, tx.Bucket([]byte("widgets")).Bucket([]byte("foo")))
+			assert.NotNil(t, tx.Bucket([]byte("widgets")).Bucket([]byte("foo")).Bucket([]byte("bar")))
+			assert.Equal(t, []byte("bat"), tx.Bucket([]byte("widgets")).Bucket([]byte("foo")).Bucket([]byte("bar")).Get([]byte("baz")))
+			assert.NoError(t, tx.DeleteBucket([]byte("widgets")))
+			return nil
+		})
+		db.View(func(tx *Tx) error {
+			assert.Nil(t, tx.Bucket([]byte("widgets")))
+			return nil
+		})
+	})
+}
+
+// Ensure that deleting a child bucket with multiple pages causes all pages to get collected.
+func TestBucket_DeleteBucket_Large(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).CreateBucket([]byte("foo")))
+			b := tx.Bucket([]byte("widgets")).Bucket([]byte("foo"))
+			for i := 0; i < 1000; i++ {
+				assert.NoError(t, b.Put([]byte(fmt.Sprintf("%d", i)), []byte(fmt.Sprintf("%0100d", i))))
+			}
+			return nil
+		})
+		db.Update(func(tx *Tx) error {
+			assert.NoError(t, tx.DeleteBucket([]byte("widgets")))
+			return nil
+		})
+
+		// NOTE: Consistency check in withOpenDB() will error if pages not freed properly.
+	})
+}
+
+// Ensure that a simple value retrieved via Bucket() returns a nil.
+func TestBucket_Bucket_IncompatibleValue(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar")))
+			assert.Nil(t, tx.Bucket([]byte("widgets")).Bucket([]byte("foo")))
+			return nil
+		})
+	})
+}
+
+// Ensure that creating a bucket on an existing non-bucket key returns an error.
+func TestBucket_CreateBucket_IncompatibleValue(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar")))
+			assert.Equal(t, ErrIncompatibleValue, tx.Bucket([]byte("widgets")).CreateBucket([]byte("foo")))
+			return nil
+		})
+	})
+}
+
+// Ensure that deleting a bucket on an existing non-bucket key returns an error.
+func TestBucket_DeleteBucket_IncompatibleValue(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
+			assert.NoError(t, tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar")))
+			assert.Equal(t, ErrIncompatibleValue, tx.Bucket([]byte("widgets")).DeleteBucket([]byte("foo")))
 			return nil
 		})
 	})
 }
 
 // Ensure that a bucket can return an autoincrementing sequence.
-func TestBucketNextSequence(t *testing.T) {
+func TestBucket_NextSequence(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.CreateBucket("woojits")
+			tx.CreateBucket([]byte("widgets"))
+			tx.CreateBucket([]byte("woojits"))
 
 			// Make sure sequence increments.
-			seq, err := tx.Bucket("widgets").NextSequence()
+			seq, err := tx.Bucket([]byte("widgets")).NextSequence()
 			assert.NoError(t, err)
 			assert.Equal(t, seq, 1)
-			seq, err = tx.Bucket("widgets").NextSequence()
+			seq, err = tx.Bucket([]byte("widgets")).NextSequence()
 			assert.NoError(t, err)
 			assert.Equal(t, seq, 2)
 
 			// Buckets should be separate.
-			seq, err = tx.Bucket("woojits").NextSequence()
+			seq, err = tx.Bucket([]byte("woojits")).NextSequence()
 			assert.NoError(t, err)
 			assert.Equal(t, seq, 1)
 			return nil
@@ -125,31 +319,31 @@ func TestBucketNextSequence(t *testing.T) {
 }
 
 // Ensure that retrieving the next sequence on a read-only bucket returns an error.
-func TestBucketNextSequenceReadOnly(t *testing.T) {
+func TestBucket_NextSequence_ReadOnly(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
 			return nil
 		})
 		db.View(func(tx *Tx) error {
-			b := tx.Bucket("widgets")
+			b := tx.Bucket([]byte("widgets"))
 			i, err := b.NextSequence()
 			assert.Equal(t, i, 0)
-			assert.Equal(t, err, ErrBucketNotWritable)
+			assert.Equal(t, err, ErrTxNotWritable)
 			return nil
 		})
 	})
 }
 
 // Ensure that incrementing past the maximum sequence number will return an error.
-func TestBucketNextSequenceOverflow(t *testing.T) {
+func TestBucket_NextSequence_Overflow(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
 			return nil
 		})
 		db.Update(func(tx *Tx) error {
-			b := tx.Bucket("widgets")
+			b := tx.Bucket([]byte("widgets"))
 			b.bucket.sequence = uint64(maxInt)
 			seq, err := b.NextSequence()
 			assert.Equal(t, err, ErrSequenceOverflow)
@@ -159,17 +353,29 @@ func TestBucketNextSequenceOverflow(t *testing.T) {
 	})
 }
 
-// Ensure a database can loop over all key/value pairs in a bucket.
-func TestBucketForEach(t *testing.T) {
+// Ensure that retrieving the next sequence for a bucket on a closed database return an error.
+func TestBucket_NextSequence_Closed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.Begin(true)
+		tx.CreateBucket([]byte("widgets"))
+		b := tx.Bucket([]byte("widgets"))
+		tx.Rollback()
+		_, err := b.NextSequence()
+		assert.Equal(t, ErrTxClosed, err)
+	})
+}
+
+// Ensure a user can loop over all key/value pairs in a bucket.
+func TestBucket_ForEach(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("foo"), []byte("0000"))
-			tx.Bucket("widgets").Put([]byte("baz"), []byte("0001"))
-			tx.Bucket("widgets").Put([]byte("bar"), []byte("0002"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("0000"))
+			tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte("0001"))
+			tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte("0002"))
 
 			var index int
-			err := tx.Bucket("widgets").ForEach(func(k, v []byte) error {
+			err := tx.Bucket([]byte("widgets")).ForEach(func(k, v []byte) error {
 				switch index {
 				case 0:
 					assert.Equal(t, k, []byte("bar"))
@@ -192,16 +398,16 @@ func TestBucketForEach(t *testing.T) {
 }
 
 // Ensure a database can stop iteration early.
-func TestBucketForEachShortCircuit(t *testing.T) {
+func TestBucket_ForEach_ShortCircuit(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("bar"), []byte("0000"))
-			tx.Bucket("widgets").Put([]byte("baz"), []byte("0000"))
-			tx.Bucket("widgets").Put([]byte("foo"), []byte("0000"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte("0000"))
+			tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte("0000"))
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("0000"))
 
 			var index int
-			err := tx.Bucket("widgets").ForEach(func(k, v []byte) error {
+			err := tx.Bucket([]byte("widgets")).ForEach(func(k, v []byte) error {
 				index++
 				if bytes.Equal(k, []byte("baz")) {
 					return errors.New("marker")
@@ -215,14 +421,26 @@ func TestBucketForEachShortCircuit(t *testing.T) {
 	})
 }
 
+// Ensure that looping over a bucket on a closed database returns an error.
+func TestBucket_ForEach_Closed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.Begin(true)
+		tx.CreateBucket([]byte("widgets"))
+		b := tx.Bucket([]byte("widgets"))
+		tx.Rollback()
+		err := b.ForEach(func(k, v []byte) error { return nil })
+		assert.Equal(t, ErrTxClosed, err)
+	})
+}
+
 // Ensure that an error is returned when inserting with an empty key.
-func TestBucketPutEmptyKey(t *testing.T) {
+func TestBucket_Put_EmptyKey(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			err := tx.Bucket("widgets").Put([]byte(""), []byte("bar"))
+			tx.CreateBucket([]byte("widgets"))
+			err := tx.Bucket([]byte("widgets")).Put([]byte(""), []byte("bar"))
 			assert.Equal(t, err, ErrKeyRequired)
-			err = tx.Bucket("widgets").Put(nil, []byte("bar"))
+			err = tx.Bucket([]byte("widgets")).Put(nil, []byte("bar"))
 			assert.Equal(t, err, ErrKeyRequired)
 			return nil
 		})
@@ -230,11 +448,11 @@ func TestBucketPutEmptyKey(t *testing.T) {
 }
 
 // Ensure that an error is returned when inserting with a key that's too large.
-func TestBucketPutKeyTooLarge(t *testing.T) {
+func TestBucket_Put_KeyTooLarge(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			err := tx.Bucket("widgets").Put(make([]byte, 32769), []byte("bar"))
+			tx.CreateBucket([]byte("widgets"))
+			err := tx.Bucket([]byte("widgets")).Put(make([]byte, 32769), []byte("bar"))
 			assert.Equal(t, err, ErrKeyTooLarge)
 			return nil
 		})
@@ -242,54 +460,35 @@ func TestBucketPutKeyTooLarge(t *testing.T) {
 }
 
 // Ensure a bucket can calculate stats.
-func TestBucketStat(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test in short mode.")
-	}
-
+func TestBucket_Stat(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			// Add bucket with lots of keys.
-			tx.CreateBucket("widgets")
-			b := tx.Bucket("widgets")
-			for i := 0; i < 100000; i++ {
-				b.Put([]byte(strconv.Itoa(i)), []byte(strconv.Itoa(i)))
-			}
-
 			// Add bucket with fewer keys but one big value.
-			tx.CreateBucket("woojits")
-			b = tx.Bucket("woojits")
+			assert.NoError(t, tx.CreateBucket([]byte("woojits")))
+			b := tx.Bucket([]byte("woojits"))
 			for i := 0; i < 500; i++ {
 				b.Put([]byte(strconv.Itoa(i)), []byte(strconv.Itoa(i)))
 			}
 			b.Put([]byte("really-big-value"), []byte(strings.Repeat("*", 10000)))
 
 			// Add a bucket that fits on a single root leaf.
-			tx.CreateBucket("whozawhats")
-			b = tx.Bucket("whozawhats")
+			assert.NoError(t, tx.CreateBucket([]byte("whozawhats")))
+			b = tx.Bucket([]byte("whozawhats"))
 			b.Put([]byte("foo"), []byte("bar"))
 
 			return nil
 		})
 		mustCheck(db)
 		db.View(func(tx *Tx) error {
-			b := tx.Bucket("widgets")
+			b := tx.Bucket([]byte("woojits"))
 			stat := b.Stat()
-			assert.Equal(t, stat.BranchPageCount, 15)
-			assert.Equal(t, stat.LeafPageCount, 1281)
-			assert.Equal(t, stat.OverflowPageCount, 0)
-			assert.Equal(t, stat.KeyCount, 100000)
-			assert.Equal(t, stat.MaxDepth, 3)
-
-			b = tx.Bucket("woojits")
-			stat = b.Stat()
 			assert.Equal(t, stat.BranchPageCount, 1)
 			assert.Equal(t, stat.LeafPageCount, 6)
 			assert.Equal(t, stat.OverflowPageCount, 2)
 			assert.Equal(t, stat.KeyCount, 501)
 			assert.Equal(t, stat.MaxDepth, 2)
 
-			b = tx.Bucket("whozawhats")
+			b = tx.Bucket([]byte("whozawhats"))
 			stat = b.Stat()
 			assert.Equal(t, stat.BranchPageCount, 0)
 			assert.Equal(t, stat.LeafPageCount, 1)
@@ -302,8 +501,38 @@ func TestBucketStat(t *testing.T) {
 	})
 }
 
+// Ensure a large bucket can calculate stats.
+func TestBucket_Stat_Large(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode.")
+	}
+
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			// Add bucket with lots of keys.
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			for i := 0; i < 100000; i++ {
+				b.Put([]byte(strconv.Itoa(i)), []byte(strconv.Itoa(i)))
+			}
+			return nil
+		})
+		mustCheck(db)
+		db.View(func(tx *Tx) error {
+			b := tx.Bucket([]byte("widgets"))
+			stat := b.Stat()
+			assert.Equal(t, stat.BranchPageCount, 15)
+			assert.Equal(t, stat.LeafPageCount, 1281)
+			assert.Equal(t, stat.OverflowPageCount, 0)
+			assert.Equal(t, stat.KeyCount, 100000)
+			assert.Equal(t, stat.MaxDepth, 3)
+			return nil
+		})
+	})
+}
+
 // Ensure that a bucket can write random keys and values across multiple transactions.
-func TestBucketPutSingle(t *testing.T) {
+func TestBucket_Put_Single(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping test in short mode.")
 	}
@@ -314,11 +543,11 @@ func TestBucketPutSingle(t *testing.T) {
 			m := make(map[string][]byte)
 
 			db.Update(func(tx *Tx) error {
-				return tx.CreateBucket("widgets")
+				return tx.CreateBucket([]byte("widgets"))
 			})
 			for _, item := range items {
 				db.Update(func(tx *Tx) error {
-					if err := tx.Bucket("widgets").Put(item.Key, item.Value); err != nil {
+					if err := tx.Bucket([]byte("widgets")).Put(item.Key, item.Value); err != nil {
 						panic("put error: " + err.Error())
 					}
 					m[string(item.Key)] = item.Value
@@ -329,10 +558,10 @@ func TestBucketPutSingle(t *testing.T) {
 				db.View(func(tx *Tx) error {
 					i := 0
 					for k, v := range m {
-						value := tx.Bucket("widgets").Get([]byte(k))
+						value := tx.Bucket([]byte("widgets")).Get([]byte(k))
 						if !bytes.Equal(value, v) {
-							db.CopyFile("/tmp/bolt.put.single.db", 0666)
-							t.Fatalf("value mismatch [run %d] (%d of %d):\nkey: %x\ngot: %x\nexp: %x", index, i, len(m), []byte(k), value, v)
+							t.Logf("value mismatch [run %d] (%d of %d):\nkey: %x\ngot: %x\nexp: %x", index, i, len(m), []byte(k), value, v)
+							copyAndFailNow(t, db)
 						}
 						i++
 					}
@@ -347,11 +576,10 @@ func TestBucketPutSingle(t *testing.T) {
 	if err := quick.Check(f, qconfig()); err != nil {
 		t.Error(err)
 	}
-	fmt.Fprint(os.Stderr, "\n")
 }
 
 // Ensure that a transaction can insert multiple key/value pairs at once.
-func TestBucketPutMultiple(t *testing.T) {
+func TestBucket_Put_Multiple(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping test in short mode.")
 	}
@@ -360,10 +588,10 @@ func TestBucketPutMultiple(t *testing.T) {
 		withOpenDB(func(db *DB, path string) {
 			// Bulk insert all values.
 			db.Update(func(tx *Tx) error {
-				return tx.CreateBucket("widgets")
+				return tx.CreateBucket([]byte("widgets"))
 			})
 			err := db.Update(func(tx *Tx) error {
-				b := tx.Bucket("widgets")
+				b := tx.Bucket([]byte("widgets"))
 				for _, item := range items {
 					assert.NoError(t, b.Put(item.Key, item.Value))
 				}
@@ -373,12 +601,11 @@ func TestBucketPutMultiple(t *testing.T) {
 
 			// Verify all items exist.
 			db.View(func(tx *Tx) error {
-				b := tx.Bucket("widgets")
+				b := tx.Bucket([]byte("widgets"))
 				for _, item := range items {
 					value := b.Get(item.Key)
 					if !assert.Equal(t, item.Value, value) {
-						db.CopyFile("/tmp/bolt.put.multiple.db", 0666)
-						t.FailNow()
+						copyAndFailNow(t, db)
 					}
 				}
 				return nil
@@ -389,11 +616,10 @@ func TestBucketPutMultiple(t *testing.T) {
 	if err := quick.Check(f, qconfig()); err != nil {
 		t.Error(err)
 	}
-	fmt.Fprint(os.Stderr, "\n")
 }
 
 // Ensure that a transaction can delete all key/value pairs and return to a single leaf page.
-func TestBucketDeleteQuick(t *testing.T) {
+func TestBucket_Delete_Quick(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping test in short mode.")
 	}
@@ -402,10 +628,10 @@ func TestBucketDeleteQuick(t *testing.T) {
 		withOpenDB(func(db *DB, path string) {
 			// Bulk insert all values.
 			db.Update(func(tx *Tx) error {
-				return tx.CreateBucket("widgets")
+				return tx.CreateBucket([]byte("widgets"))
 			})
 			err := db.Update(func(tx *Tx) error {
-				b := tx.Bucket("widgets")
+				b := tx.Bucket([]byte("widgets"))
 				for _, item := range items {
 					assert.NoError(t, b.Put(item.Key, item.Value))
 				}
@@ -416,13 +642,13 @@ func TestBucketDeleteQuick(t *testing.T) {
 			// Remove items one at a time and check consistency.
 			for i, item := range items {
 				err := db.Update(func(tx *Tx) error {
-					return tx.Bucket("widgets").Delete(item.Key)
+					return tx.Bucket([]byte("widgets")).Delete(item.Key)
 				})
 				assert.NoError(t, err)
 
 				// Anything before our deletion index should be nil.
 				db.View(func(tx *Tx) error {
-					b := tx.Bucket("widgets")
+					b := tx.Bucket([]byte("widgets"))
 					for j, exp := range items {
 						if j > i {
 							value := b.Get(exp.Key)
@@ -445,5 +671,99 @@ func TestBucketDeleteQuick(t *testing.T) {
 	if err := quick.Check(f, qconfig()); err != nil {
 		t.Error(err)
 	}
-	fmt.Fprint(os.Stderr, "\n")
+}
+
+func ExampleBucket_Put() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Start a write transaction.
+	db.Update(func(tx *Tx) error {
+		// Create a bucket.
+		tx.CreateBucket([]byte("widgets"))
+
+		// Set the value "bar" for the key "foo".
+		tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
+		return nil
+	})
+
+	// Read value back in a different read-only transaction.
+	db.Update(func(tx *Tx) error {
+		value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
+		fmt.Printf("The value of 'foo' is: %s\n", string(value))
+		return nil
+	})
+
+	// Output:
+	// The value of 'foo' is: bar
+}
+
+func ExampleBucket_Delete() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Start a write transaction.
+	db.Update(func(tx *Tx) error {
+		// Create a bucket.
+		tx.CreateBucket([]byte("widgets"))
+		b := tx.Bucket([]byte("widgets"))
+
+		// Set the value "bar" for the key "foo".
+		b.Put([]byte("foo"), []byte("bar"))
+
+		// Retrieve the key back from the database and verify it.
+		value := b.Get([]byte("foo"))
+		fmt.Printf("The value of 'foo' was: %s\n", string(value))
+		return nil
+	})
+
+	// Delete the key in a different write transaction.
+	db.Update(func(tx *Tx) error {
+		return tx.Bucket([]byte("widgets")).Delete([]byte("foo"))
+	})
+
+	// Retrieve the key again.
+	db.View(func(tx *Tx) error {
+		value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
+		if value == nil {
+			fmt.Printf("The value of 'foo' is now: nil\n")
+		}
+		return nil
+	})
+
+	// Output:
+	// The value of 'foo' was: bar
+	// The value of 'foo' is now: nil
+}
+
+func ExampleBucket_ForEach() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Insert data into a bucket.
+	db.Update(func(tx *Tx) error {
+		tx.CreateBucket([]byte("animals"))
+		b := tx.Bucket([]byte("animals"))
+		b.Put([]byte("dog"), []byte("fun"))
+		b.Put([]byte("cat"), []byte("lame"))
+		b.Put([]byte("liger"), []byte("awesome"))
+
+		// Iterate over items in sorted key order.
+		b.ForEach(func(k, v []byte) error {
+			fmt.Printf("A %s is %s.\n", string(k), string(v))
+			return nil
+		})
+		return nil
+	})
+
+	// Output:
+	// A cat is lame.
+	// A dog is fun.
+	// A liger is awesome.
 }
diff --git a/buckets.go b/buckets.go
deleted file mode 100644
index 3226873..0000000
--- a/buckets.go
+++ /dev/null
@@ -1,110 +0,0 @@
-package bolt
-
-import (
-	"sort"
-	"unsafe"
-)
-
-// buckets represents a in-memory buckets page.
-type buckets struct {
-	pgid  pgid
-	items map[string]*bucket
-}
-
-// size returns the size of the page after serialization.
-func (b *buckets) size() int {
-	var size = pageHeaderSize
-	for key := range b.items {
-		size += int(unsafe.Sizeof(bucket{})) + len(key)
-	}
-	return size
-}
-
-// get retrieves a bucket by name.
-func (b *buckets) get(key string) *bucket {
-	return b.items[key]
-}
-
-// put sets a new value for a bucket.
-func (b *buckets) put(key string, item *bucket) {
-	b.items[key] = item
-}
-
-// del deletes a bucket by name.
-func (b *buckets) del(key string) {
-	if item := b.items[key]; item != nil {
-		delete(b.items, key)
-	}
-}
-
-// read initializes the data from an on-disk page.
-func (b *buckets) read(p *page) {
-	b.pgid = p.id
-	b.items = make(map[string]*bucket)
-
-	var items []*bucket
-	var keys []string
-
-	// Read items.
-	nodes := (*[maxNodesPerPage]bucket)(unsafe.Pointer(&p.ptr))
-	for i := 0; i < int(p.count); i++ {
-		node := &nodes[i]
-		items = append(items, node)
-	}
-
-	// Read keys.
-	buf := (*[maxAllocSize]byte)(unsafe.Pointer(&nodes[p.count]))[:]
-	for i := 0; i < int(p.count); i++ {
-		size := int(buf[0])
-		buf = buf[1:]
-		keys = append(keys, string(buf[:size]))
-		buf = buf[size:]
-	}
-
-	// Associate keys and items.
-	for index, key := range keys {
-		b.items[key] = &bucket{
-			root:     items[index].root,
-			sequence: items[index].sequence,
-		}
-	}
-}
-
-// write writes the items onto a page.
-func (b *buckets) write(p *page) {
-	// Initialize page.
-	p.flags |= bucketsPageFlag
-	p.count = uint16(len(b.items))
-
-	// Sort keys.
-	var keys []string
-	for key := range b.items {
-		keys = append(keys, key)
-	}
-	sort.StringSlice(keys).Sort()
-
-	// Write each bucket to the page.
-	items := (*[maxNodesPerPage]bucket)(unsafe.Pointer(&p.ptr))
-	for index, key := range keys {
-		items[index] = *b.items[key]
-	}
-
-	// Write each key to the page.
-	buf := (*[maxAllocSize]byte)(unsafe.Pointer(&items[p.count]))[:]
-	for _, key := range keys {
-		buf[0] = byte(len(key))
-		buf = buf[1:]
-		copy(buf, []byte(key))
-		buf = buf[len(key):]
-	}
-}
-
-// updateRoot finds a bucket by root id and then updates it to point to a new root.
-func (b *buckets) updateRoot(oldid, newid pgid) {
-	for _, b := range b.items {
-		if b.root == oldid {
-			b.root = newid
-			return
-		}
-	}
-}
diff --git a/buckets_test.go b/buckets_test.go
deleted file mode 100644
index 0fc6288..0000000
--- a/buckets_test.go
+++ /dev/null
@@ -1,70 +0,0 @@
-package bolt
-
-import (
-	"testing"
-	"unsafe"
-
-	"github.com/stretchr/testify/assert"
-)
-
-// Ensure that a buckets page can set a bucket.
-func TestBucketsPut(t *testing.T) {
-	b := &buckets{items: make(map[string]*bucket)}
-	b.put("foo", &bucket{root: 2})
-	b.put("bar", &bucket{root: 3})
-	b.put("foo", &bucket{root: 4})
-	assert.Equal(t, len(b.items), 2)
-	assert.Equal(t, b.get("foo").root, pgid(4))
-	assert.Equal(t, b.get("bar").root, pgid(3))
-	assert.Nil(t, b.get("no_such_bucket"))
-}
-
-// Ensure that a buckets page can deserialize from a page.
-func TestBucketsRead(t *testing.T) {
-	// Create a page.
-	var buf [4096]byte
-	page := (*page)(unsafe.Pointer(&buf[0]))
-	page.count = 2
-
-	// Insert 2 items at the beginning.
-	s := (*[3]bucket)(unsafe.Pointer(&page.ptr))
-	s[0] = bucket{root: 3}
-	s[1] = bucket{root: 4}
-
-	// Write data for the nodes at the end.
-	data := (*[4096]byte)(unsafe.Pointer(&s[2]))
-	data[0] = 3
-	copy(data[1:], []byte("bar"))
-	data[4] = 10
-	copy(data[5:], []byte("helloworld"))
-
-	// Deserialize page into a buckets page.
-	b := &buckets{items: make(map[string]*bucket)}
-	b.read(page)
-
-	// Check that there are two items with correct data.
-	assert.Equal(t, len(b.items), 2)
-	assert.Equal(t, b.get("bar").root, pgid(3))
-	assert.Equal(t, b.get("helloworld").root, pgid(4))
-}
-
-// Ensure that a buckets page can serialize itself.
-func TestBucketsWrite(t *testing.T) {
-	b := &buckets{items: make(map[string]*bucket)}
-	b.put("foo", &bucket{root: 2})
-	b.put("bar", &bucket{root: 3})
-
-	// Write it to a page.
-	var buf [4096]byte
-	p := (*page)(unsafe.Pointer(&buf[0]))
-	b.write(p)
-
-	// Read the page back in.
-	b2 := &buckets{items: make(map[string]*bucket)}
-	b2.read(p)
-
-	// Check that the two pages are the same.
-	assert.Equal(t, len(b.items), 2)
-	assert.Equal(t, b.get("foo").root, pgid(2))
-	assert.Equal(t, b.get("bar").root, pgid(3))
-}
diff --git a/cmd/bolt/buckets.go b/cmd/bolt/buckets.go
index 10766a6..48395d8 100644
--- a/cmd/bolt/buckets.go
+++ b/cmd/bolt/buckets.go
@@ -21,10 +21,10 @@ func Buckets(path string) {
 	defer db.Close()
 
 	err = db.View(func(tx *bolt.Tx) error {
-		for _, b := range tx.Buckets() {
-			println(b.Name())
-		}
-		return nil
+		return tx.ForEach(func(name []byte, _ *bolt.Bucket) error {
+			println(string(name))
+			return nil
+		})
 	})
 	if err != nil {
 		fatal(err)
diff --git a/cmd/bolt/buckets_test.go b/cmd/bolt/buckets_test.go
index 5f72bb2..27ee619 100644
--- a/cmd/bolt/buckets_test.go
+++ b/cmd/bolt/buckets_test.go
@@ -13,9 +13,9 @@ func TestBuckets(t *testing.T) {
 	SetTestMode(true)
 	open(func(db *bolt.DB, path string) {
 		db.Update(func(tx *bolt.Tx) error {
-			tx.CreateBucket("woojits")
-			tx.CreateBucket("widgets")
-			tx.CreateBucket("whatchits")
+			tx.CreateBucket([]byte("woojits"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.CreateBucket([]byte("whatchits"))
 			return nil
 		})
 		db.Close()
diff --git a/cmd/bolt/export.go b/cmd/bolt/export.go
index f3cafc1..2dcbc1f 100644
--- a/cmd/bolt/export.go
+++ b/cmd/bolt/export.go
@@ -23,25 +23,33 @@ func Export(path string) {
 	}
 	defer db.Close()
 
-	db.View(func(tx *bolt.Tx) error {
+	err = db.View(func(tx *bolt.Tx) error {
 		// Loop over every bucket and export it as a raw message.
 		var root []*rawMessage
-		for _, b := range tx.Buckets() {
+		err := tx.ForEach(func(name []byte, b *bolt.Bucket) error {
 			message, err := exportBucket(b)
 			if err != nil {
 				fatal(err)
 			}
+			message.Key = name
 			root = append(root, message)
+			return nil
+		})
+		if err != nil {
+			return err
 		}
 
 		// Encode all buckets into JSON.
 		output, err := json.Marshal(root)
 		if err != nil {
-			fatal("encode: ", err)
+			return fmt.Errorf("encode: ", err)
 		}
 		print(string(output))
 		return nil
 	})
+	if err != nil {
+		fatal(err)
+	}
 }
 
 func exportBucket(b *bolt.Bucket) (*rawMessage, error) {
@@ -50,11 +58,22 @@ func exportBucket(b *bolt.Bucket) (*rawMessage, error) {
 	err := b.ForEach(func(k, v []byte) error {
 		var err error
 
+		// If there is no value then it is a bucket.
+		if v == nil {
+			child, err := exportBucket(b.Bucket(k))
+			if err != nil {
+				return fmt.Errorf("bucket: %s", err)
+			}
+			child.Key = k
+			children = append(children, child)
+			return nil
+		}
+
+		// Otherwise it's a regular key.
 		var child = &rawMessage{Key: k}
 		if child.Value, err = json.Marshal(v); err != nil {
 			return fmt.Errorf("value: %s", err)
 		}
-
 		children = append(children, child)
 		return nil
 	})
@@ -64,7 +83,6 @@ func exportBucket(b *bolt.Bucket) (*rawMessage, error) {
 
 	// Encode bucket into a raw message.
 	var root = rawMessage{Type: "bucket"}
-	root.Key = []byte(b.Name())
 	if root.Value, err = json.Marshal(children); err != nil {
 		return nil, fmt.Errorf("children: %s", err)
 	}
diff --git a/cmd/bolt/export_test.go b/cmd/bolt/export_test.go
index 3d6c21a..13f57d1 100644
--- a/cmd/bolt/export_test.go
+++ b/cmd/bolt/export_test.go
@@ -13,19 +13,26 @@ func TestExport(t *testing.T) {
 	SetTestMode(true)
 	open(func(db *bolt.DB, path string) {
 		db.Update(func(tx *bolt.Tx) error {
-			tx.CreateBucket("widgets")
-			b := tx.Bucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
 			b.Put([]byte("foo"), []byte("0000"))
 			b.Put([]byte("bar"), []byte(""))
 
-			tx.CreateBucket("woojits")
-			b = tx.Bucket("woojits")
+			tx.CreateBucket([]byte("woojits"))
+			b = tx.Bucket([]byte("woojits"))
 			b.Put([]byte("baz"), []byte("XXXX"))
+
+			b.CreateBucket([]byte("woojits/subbucket"))
+			b = b.Bucket([]byte("woojits/subbucket"))
+			b.Put([]byte("bat"), []byte("A"))
+
+			tx.CreateBucket([]byte("empty"))
+
 			return nil
 		})
 		db.Close()
 		output := run("export", path)
-		assert.Equal(t, `[{"type":"bucket","key":"d2lkZ2V0cw==","value":[{"key":"YmFy","value":""},{"key":"Zm9v","value":"MDAwMA=="}]},{"type":"bucket","key":"d29vaml0cw==","value":[{"key":"YmF6","value":"WFhYWA=="}]}]`, output)
+		assert.Equal(t, `[{"type":"bucket","key":"ZW1wdHk=","value":[]},{"type":"bucket","key":"d2lkZ2V0cw==","value":[{"key":"YmFy","value":""},{"key":"Zm9v","value":"MDAwMA=="}]},{"type":"bucket","key":"d29vaml0cw==","value":[{"key":"YmF6","value":"WFhYWA=="},{"type":"bucket","key":"d29vaml0cy9zdWJidWNrZXQ=","value":[{"key":"YmF0","value":"QQ=="}]}]}]`, output)
 	})
 }
 
diff --git a/cmd/bolt/get.go b/cmd/bolt/get.go
index 10216e3..6ea7f04 100644
--- a/cmd/bolt/get.go
+++ b/cmd/bolt/get.go
@@ -22,7 +22,7 @@ func Get(path, name, key string) {
 
 	err = db.View(func(tx *bolt.Tx) error {
 		// Find bucket.
-		b := tx.Bucket(name)
+		b := tx.Bucket([]byte(name))
 		if b == nil {
 			fatalf("bucket not found: %s", name)
 			return nil
diff --git a/cmd/bolt/get_test.go b/cmd/bolt/get_test.go
index 09883d4..d491971 100644
--- a/cmd/bolt/get_test.go
+++ b/cmd/bolt/get_test.go
@@ -13,8 +13,8 @@ func TestGet(t *testing.T) {
 	SetTestMode(true)
 	open(func(db *bolt.DB, path string) {
 		db.Update(func(tx *bolt.Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
 			return nil
 		})
 		db.Close()
@@ -45,7 +45,7 @@ func TestGetKeyNotFound(t *testing.T) {
 	SetTestMode(true)
 	open(func(db *bolt.DB, path string) {
 		db.Update(func(tx *bolt.Tx) error {
-			return tx.CreateBucket("widgets")
+			return tx.CreateBucket([]byte("widgets"))
 		})
 		db.Close()
 		output := run("get", path, "widgets", "foo")
diff --git a/cmd/bolt/import.go b/cmd/bolt/import.go
index ec8cee1..7554ae7 100644
--- a/cmd/bolt/import.go
+++ b/cmd/bolt/import.go
@@ -41,7 +41,7 @@ func Import(path string, input string) {
 			}
 
 			// Create the bucket if it doesn't exist.
-			if err := tx.CreateBucketIfNotExists(string(message.Key)); err != nil {
+			if err := tx.CreateBucketIfNotExists(message.Key); err != nil {
 				return fmt.Errorf("create bucket: %s", err)
 			}
 
@@ -52,7 +52,7 @@ func Import(path string, input string) {
 			}
 
 			// Import all the values into the bucket.
-			b := tx.Bucket(string(message.Key))
+			b := tx.Bucket(message.Key)
 			if err := importBucket(b, children); err != nil {
 				return fmt.Errorf("import bucket: %s", err)
 			}
@@ -67,7 +67,28 @@ func Import(path string, input string) {
 func importBucket(b *bolt.Bucket, children []*rawMessage) error {
 	// Decode each message into a key/value pair.
 	for _, child := range children {
-		// Decode the base64 value.
+		// Bucket messages are handled recursively.
+		if child.Type == "bucket" {
+			// Create the bucket if it doesn't exist.
+			if err := b.CreateBucketIfNotExists(child.Key); err != nil {
+				return fmt.Errorf("create bucket: %s", err)
+			}
+
+			// Decode child messages.
+			var subchildren []*rawMessage
+			if err := json.Unmarshal(child.Value, &subchildren); err != nil {
+				return fmt.Errorf("decode children: %s", err)
+			}
+
+			// Import subbucket.
+			subbucket := b.Bucket(child.Key)
+			if err := importBucket(subbucket, subchildren); err != nil {
+				return fmt.Errorf("import bucket: %s", err)
+			}
+			continue
+		}
+
+		// Non-bucket values are decoded from base64.
 		var value []byte
 		if err := json.Unmarshal(child.Value, &value); err != nil {
 			return fmt.Errorf("decode value: %s", err)
diff --git a/cmd/bolt/import_test.go b/cmd/bolt/import_test.go
index be41f5c..263f561 100644
--- a/cmd/bolt/import_test.go
+++ b/cmd/bolt/import_test.go
@@ -15,7 +15,7 @@ func TestImport(t *testing.T) {
 
 	// Write input file.
 	input := tempfile()
-	assert.NoError(t, ioutil.WriteFile(input, []byte(`[{"type":"bucket","key":"d2lkZ2V0cw==","value":[{"key":"YmFy","value":""},{"key":"Zm9v","value":"MDAwMA=="}]},{"type":"bucket","key":"d29vaml0cw==","value":[{"key":"YmF6","value":"WFhYWA=="}]}]`), 0600))
+	assert.NoError(t, ioutil.WriteFile(input, []byte(`[{"type":"bucket","key":"ZW1wdHk=","value":[]},{"type":"bucket","key":"d2lkZ2V0cw==","value":[{"key":"YmFy","value":""},{"key":"Zm9v","value":"MDAwMA=="}]},{"type":"bucket","key":"d29vaml0cw==","value":[{"key":"YmF6","value":"WFhYWA=="},{"type":"bucket","key":"d29vaml0cy9zdWJidWNrZXQ=","value":[{"key":"YmF0","value":"QQ=="}]}]}]`), 0600))
 
 	// Import database.
 	path := tempfile()
@@ -26,15 +26,20 @@ func TestImport(t *testing.T) {
 	db, err := bolt.Open(path, 0600)
 	assert.NoError(t, err)
 	db.View(func(tx *bolt.Tx) error {
-		b := tx.Bucket("widgets")
+		assert.NotNil(t, tx.Bucket([]byte("empty")))
+
+		b := tx.Bucket([]byte("widgets"))
 		if assert.NotNil(t, b) {
 			assert.Equal(t, []byte("0000"), b.Get([]byte("foo")))
 			assert.Equal(t, []byte(""), b.Get([]byte("bar")))
 		}
 
-		b = tx.Bucket("woojits")
+		b = tx.Bucket([]byte("woojits"))
 		if assert.NotNil(t, b) {
 			assert.Equal(t, []byte("XXXX"), b.Get([]byte("baz")))
+
+			b = b.Bucket([]byte("woojits/subbucket"))
+			assert.Equal(t, []byte("A"), b.Get([]byte("bat")))
 		}
 
 		return nil
diff --git a/cmd/bolt/keys.go b/cmd/bolt/keys.go
index 56245b8..6affefe 100644
--- a/cmd/bolt/keys.go
+++ b/cmd/bolt/keys.go
@@ -22,7 +22,7 @@ func Keys(path, name string) {
 
 	err = db.View(func(tx *bolt.Tx) error {
 		// Find bucket.
-		b := tx.Bucket(name)
+		b := tx.Bucket([]byte(name))
 		if b == nil {
 			fatalf("bucket not found: %s", name)
 			return nil
diff --git a/cmd/bolt/keys_test.go b/cmd/bolt/keys_test.go
index ea530f6..2b5a9a0 100644
--- a/cmd/bolt/keys_test.go
+++ b/cmd/bolt/keys_test.go
@@ -13,10 +13,10 @@ func TestKeys(t *testing.T) {
 	SetTestMode(true)
 	open(func(db *bolt.DB, path string) {
 		db.Update(func(tx *bolt.Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("0002"), []byte(""))
-			tx.Bucket("widgets").Put([]byte("0001"), []byte(""))
-			tx.Bucket("widgets").Put([]byte("0003"), []byte(""))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("0002"), []byte(""))
+			tx.Bucket([]byte("widgets")).Put([]byte("0001"), []byte(""))
+			tx.Bucket([]byte("widgets")).Put([]byte("0003"), []byte(""))
 			return nil
 		})
 		db.Close()
diff --git a/cmd/bolt/set.go b/cmd/bolt/set.go
index ff12024..9761f44 100644
--- a/cmd/bolt/set.go
+++ b/cmd/bolt/set.go
@@ -22,7 +22,7 @@ func Set(path, name, key, value string) {
 
 	err = db.Update(func(tx *bolt.Tx) error {
 		// Find bucket.
-		b := tx.Bucket(name)
+		b := tx.Bucket([]byte(name))
 		if b == nil {
 			fatalf("bucket not found: %s", name)
 			return nil
diff --git a/cmd/bolt/set_test.go b/cmd/bolt/set_test.go
index 519d888..be07148 100644
--- a/cmd/bolt/set_test.go
+++ b/cmd/bolt/set_test.go
@@ -13,7 +13,7 @@ func TestSet(t *testing.T) {
 	SetTestMode(true)
 	open(func(db *bolt.DB, path string) {
 		db.Update(func(tx *bolt.Tx) error {
-			tx.CreateBucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
 			return nil
 		})
 		db.Close()
diff --git a/const.go b/const.go
index 00228be..4669347 100644
--- a/const.go
+++ b/const.go
@@ -1,6 +1,6 @@
 package bolt
 
-const version = 1
+const version = 2
 
 const (
 	maxUint = ^uint(0)
@@ -10,9 +10,6 @@ const (
 )
 
 const (
-	// MaxBucketNameSize is the maximum length of a bucket name, in bytes.
-	MaxBucketNameSize = 255
-
 	// MaxKeySize is the maximum length of a key, in bytes.
 	MaxKeySize = 32768
 
diff --git a/cursor.go b/cursor.go
index 2887791..f6dc79c 100644
--- a/cursor.go
+++ b/cursor.go
@@ -8,39 +8,47 @@ import (
 // Cursor represents an iterator that can traverse over all key/value pairs in a bucket in sorted order.
 // Cursors can be obtained from a transaction and are valid as long as the transaction is open.
 type Cursor struct {
-	tx    *Tx
-	root  pgid
-	stack []elemRef
+	bucket *Bucket
+	stack  []elemRef
 }
 
 // First moves the cursor to the first item in the bucket and returns its key and value.
 // If the bucket is empty then a nil key and value are returned.
 func (c *Cursor) First() (key []byte, value []byte) {
-	_assert(c.tx.db != nil, "tx closed")
+	_assert(c.bucket.tx.db != nil, "tx closed")
 	c.stack = c.stack[:0]
-	p, n := c.tx.pageNode(c.root)
+	p, n := c.bucket.pageNode(c.bucket.root)
 	c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
 	c.first()
-	return c.keyValue()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+
 }
 
 // Last moves the cursor to the last item in the bucket and returns its key and value.
 // If the bucket is empty then a nil key and value are returned.
 func (c *Cursor) Last() (key []byte, value []byte) {
-	_assert(c.tx.db != nil, "tx closed")
+	_assert(c.bucket.tx.db != nil, "tx closed")
 	c.stack = c.stack[:0]
-	p, n := c.tx.pageNode(c.root)
+	p, n := c.bucket.pageNode(c.bucket.root)
 	ref := elemRef{page: p, node: n}
 	ref.index = ref.count() - 1
 	c.stack = append(c.stack, ref)
 	c.last()
-	return c.keyValue()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
 }
 
 // Next moves the cursor to the next item in the bucket and returns its key and value.
 // If the cursor is at the end of the bucket then a nil key and value are returned.
 func (c *Cursor) Next() (key []byte, value []byte) {
-	_assert(c.tx.db != nil, "tx closed")
+	_assert(c.bucket.tx.db != nil, "tx closed")
 
 	// Attempt to move over one element until we're successful.
 	// Move up the stack as we hit the end of each page in our stack.
@@ -60,13 +68,17 @@ func (c *Cursor) Next() (key []byte, value []byte) {
 
 	// Move down the stack to find the first element of the first leaf under this branch.
 	c.first()
-	return c.keyValue()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
 }
 
 // Prev moves the cursor to the previous item in the bucket and returns its key and value.
 // If the cursor is at the beginning of the bucket then a nil key and value are returned.
 func (c *Cursor) Prev() (key []byte, value []byte) {
-	_assert(c.tx.db != nil, "tx closed")
+	_assert(c.bucket.tx.db != nil, "tx closed")
 
 	// Attempt to move back one element until we're successful.
 	// Move up the stack as we hit the beginning of each page in our stack.
@@ -86,25 +98,43 @@ func (c *Cursor) Prev() (key []byte, value []byte) {
 
 	// Move down the stack to find the last element of the last leaf under this branch.
 	c.last()
-	return c.keyValue()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
 }
 
 // Seek moves the cursor to a given key and returns it.
 // If the key does not exist then the next key is used. If no keys
 // follow, a nil value is returned.
 func (c *Cursor) Seek(seek []byte) (key []byte, value []byte) {
-	_assert(c.tx.db != nil, "tx closed")
+	k, v, flags := c.seek(seek)
+	if k == nil {
+		return nil, nil
+	} else if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// seek moves the cursor to a given key and returns it.
+// If the key does not exist then the next key is used. If no keys
+// follow, a nil value is returned.
+func (c *Cursor) seek(seek []byte) (key []byte, value []byte, flags uint32) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
 
 	// Start from root page/node and traverse to correct page.
 	c.stack = c.stack[:0]
-	c.search(seek, c.root)
+	c.search(seek, c.bucket.root)
 	ref := &c.stack[len(c.stack)-1]
 
 	// If the cursor is pointing to the end of page/node then return nil.
 	if ref.index >= ref.count() {
-		return nil, nil
+		return nil, nil, 0
 	}
 
+	// If this is a bucket then return a nil value.
 	return c.keyValue()
 }
 
@@ -124,7 +154,7 @@ func (c *Cursor) first() {
 		} else {
 			pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
 		}
-		p, n := c.tx.pageNode(pgid)
+		p, n := c.bucket.pageNode(pgid)
 		c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
 	}
 }
@@ -145,7 +175,7 @@ func (c *Cursor) last() {
 		} else {
 			pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
 		}
-		p, n := c.tx.pageNode(pgid)
+		p, n := c.bucket.pageNode(pgid)
 
 		var nextRef = elemRef{page: p, node: n}
 		nextRef.index = nextRef.count() - 1
@@ -155,7 +185,7 @@ func (c *Cursor) last() {
 
 // search recursively performs a binary search against a given page/node until it finds a given key.
 func (c *Cursor) search(key []byte, pgid pgid) {
-	p, n := c.tx.pageNode(pgid)
+	p, n := c.bucket.pageNode(pgid)
 	if p != nil {
 		_assert((p.flags&(branchPageFlag|leafPageFlag)) != 0, "invalid page type: "+p.typ())
 	}
@@ -241,25 +271,25 @@ func (c *Cursor) nsearch(key []byte) {
 }
 
 // keyValue returns the key and value of the current leaf element.
-func (c *Cursor) keyValue() ([]byte, []byte) {
+func (c *Cursor) keyValue() ([]byte, []byte, uint32) {
 	ref := &c.stack[len(c.stack)-1]
 	if ref.count() == 0 || ref.index >= ref.count() {
-		return nil, nil
+		return nil, nil, 0
 	}
 
 	// Retrieve value from node.
 	if ref.node != nil {
 		inode := &ref.node.inodes[ref.index]
-		return inode.key, inode.value
+		return inode.key, inode.value, inode.flags
 	}
 
 	// Or retrieve value from page.
 	elem := ref.page.leafPageElement(uint16(ref.index))
-	return elem.key(), elem.value()
+	return elem.key(), elem.value(), elem.flags
 }
 
 // node returns the node that the cursor is currently positioned on.
-func (c *Cursor) node(tx *Tx) *node {
+func (c *Cursor) node() *node {
 	_assert(len(c.stack) > 0, "accessing a node with a zero-length cursor stack")
 
 	// If the top of the stack is a leaf node then just return it.
@@ -270,7 +300,7 @@ func (c *Cursor) node(tx *Tx) *node {
 	// Start from root and traverse down the hierarchy.
 	var n = c.stack[0].node
 	if n == nil {
-		n = tx.node(c.stack[0].page.id, nil)
+		n = c.bucket.node(c.stack[0].page.id, nil)
 	}
 	for _, ref := range c.stack[:len(c.stack)-1] {
 		_assert(!n.isLeaf, "expected branch node")
diff --git a/cursor_test.go b/cursor_test.go
new file mode 100644
index 0000000..d9d258c
--- /dev/null
+++ b/cursor_test.go
@@ -0,0 +1,307 @@
+package bolt
+
+import (
+	"sort"
+	"testing"
+	"testing/quick"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// Ensure that a Tx cursor can seek to the appropriate keys.
+func TestCursor_Seek(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
+			b := tx.Bucket([]byte("widgets"))
+			assert.NoError(t, b.Put([]byte("foo"), []byte("0001")))
+			assert.NoError(t, b.Put([]byte("bar"), []byte("0002")))
+			assert.NoError(t, b.Put([]byte("baz"), []byte("0003")))
+			assert.NoError(t, b.CreateBucket([]byte("bkt")))
+			return nil
+		})
+		db.View(func(tx *Tx) error {
+			c := tx.Bucket([]byte("widgets")).Cursor()
+
+			// Exact match should go to the key.
+			k, v := c.Seek([]byte("bar"))
+			assert.Equal(t, []byte("bar"), k)
+			assert.Equal(t, []byte("0002"), v)
+
+			// Inexact match should go to the next key.
+			k, v = c.Seek([]byte("bas"))
+			assert.Equal(t, []byte("baz"), k)
+			assert.Equal(t, []byte("0003"), v)
+
+			// Low key should go to the first key.
+			k, v = c.Seek([]byte(""))
+			assert.Equal(t, []byte("bar"), k)
+			assert.Equal(t, []byte("0002"), v)
+
+			// High key should return no key.
+			k, v = c.Seek([]byte("zzz"))
+			assert.Nil(t, k)
+			assert.Nil(t, v)
+
+			// Buckets should return their key but no value.
+			k, v = c.Seek([]byte("bkt"))
+			assert.Equal(t, []byte("bkt"), k)
+			assert.Nil(t, v)
+
+			return nil
+		})
+	})
+}
+
+// Ensure that a cursor can iterate over an empty bucket without error.
+func TestCursor_EmptyBucket(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			return tx.CreateBucket([]byte("widgets"))
+		})
+		db.View(func(tx *Tx) error {
+			c := tx.Bucket([]byte("widgets")).Cursor()
+			k, v := c.First()
+			assert.Nil(t, k)
+			assert.Nil(t, v)
+			return nil
+		})
+	})
+}
+
+// Ensure that a Tx cursor can reverse iterate over an empty bucket without error.
+func TestCursor_EmptyBucketReverse(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			return tx.CreateBucket([]byte("widgets"))
+		})
+		db.View(func(tx *Tx) error {
+			c := tx.Bucket([]byte("widgets")).Cursor()
+			k, v := c.Last()
+			assert.Nil(t, k)
+			assert.Nil(t, v)
+			return nil
+		})
+	})
+}
+
+// Ensure that a Tx cursor can iterate over a single root with a couple elements.
+func TestCursor_LeafRoot(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte{})
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte{0})
+			tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte{1})
+			return nil
+		})
+		tx, _ := db.Begin(false)
+		c := tx.Bucket([]byte("widgets")).Cursor()
+
+		k, v := c.First()
+		assert.Equal(t, string(k), "bar")
+		assert.Equal(t, v, []byte{1})
+
+		k, v = c.Next()
+		assert.Equal(t, string(k), "baz")
+		assert.Equal(t, v, []byte{})
+
+		k, v = c.Next()
+		assert.Equal(t, string(k), "foo")
+		assert.Equal(t, v, []byte{0})
+
+		k, v = c.Next()
+		assert.Nil(t, k)
+		assert.Nil(t, v)
+
+		k, v = c.Next()
+		assert.Nil(t, k)
+		assert.Nil(t, v)
+
+		tx.Rollback()
+	})
+}
+
+// Ensure that a Tx cursor can iterate in reverse over a single root with a couple elements.
+func TestCursor_LeafRootReverse(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte{})
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte{0})
+			tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte{1})
+			return nil
+		})
+		tx, _ := db.Begin(false)
+		c := tx.Bucket([]byte("widgets")).Cursor()
+
+		k, v := c.Last()
+		assert.Equal(t, string(k), "foo")
+		assert.Equal(t, v, []byte{0})
+
+		k, v = c.Prev()
+		assert.Equal(t, string(k), "baz")
+		assert.Equal(t, v, []byte{})
+
+		k, v = c.Prev()
+		assert.Equal(t, string(k), "bar")
+		assert.Equal(t, v, []byte{1})
+
+		k, v = c.Prev()
+		assert.Nil(t, k)
+		assert.Nil(t, v)
+
+		k, v = c.Prev()
+		assert.Nil(t, k)
+		assert.Nil(t, v)
+
+		tx.Rollback()
+	})
+}
+
+// Ensure that a Tx cursor can restart from the beginning.
+func TestCursor_Restart(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte{})
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte{})
+			return nil
+		})
+
+		tx, _ := db.Begin(false)
+		c := tx.Bucket([]byte("widgets")).Cursor()
+
+		k, _ := c.First()
+		assert.Equal(t, string(k), "bar")
+
+		k, _ = c.Next()
+		assert.Equal(t, string(k), "foo")
+
+		k, _ = c.First()
+		assert.Equal(t, string(k), "bar")
+
+		k, _ = c.Next()
+		assert.Equal(t, string(k), "foo")
+
+		tx.Rollback()
+	})
+}
+
+// Ensure that a Tx can iterate over all elements in a bucket.
+func TestCursor_Iterate(t *testing.T) {
+	f := func(items testdata) bool {
+		withOpenDB(func(db *DB, path string) {
+			// Bulk insert all values.
+			tx, _ := db.Begin(true)
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			for _, item := range items {
+				assert.NoError(t, b.Put(item.Key, item.Value))
+			}
+			assert.NoError(t, tx.Commit())
+
+			// Sort test data.
+			sort.Sort(items)
+
+			// Iterate over all items and check consistency.
+			var index = 0
+			tx, _ = db.Begin(false)
+			c := tx.Bucket([]byte("widgets")).Cursor()
+			for k, v := c.First(); k != nil && index < len(items); k, v = c.Next() {
+				assert.Equal(t, k, items[index].Key)
+				assert.Equal(t, v, items[index].Value)
+				index++
+			}
+			assert.Equal(t, len(items), index)
+			tx.Rollback()
+		})
+		return true
+	}
+	if err := quick.Check(f, qconfig()); err != nil {
+		t.Error(err)
+	}
+}
+
+// Ensure that a transaction can iterate over all elements in a bucket in reverse.
+func TestCursor_Iterate_Reverse(t *testing.T) {
+	f := func(items testdata) bool {
+		withOpenDB(func(db *DB, path string) {
+			// Bulk insert all values.
+			tx, _ := db.Begin(true)
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			for _, item := range items {
+				assert.NoError(t, b.Put(item.Key, item.Value))
+			}
+			assert.NoError(t, tx.Commit())
+
+			// Sort test data.
+			sort.Sort(revtestdata(items))
+
+			// Iterate over all items and check consistency.
+			var index = 0
+			tx, _ = db.Begin(false)
+			c := tx.Bucket([]byte("widgets")).Cursor()
+			for k, v := c.Last(); k != nil && index < len(items); k, v = c.Prev() {
+				assert.Equal(t, k, items[index].Key)
+				assert.Equal(t, v, items[index].Value)
+				index++
+			}
+			assert.Equal(t, len(items), index)
+			tx.Rollback()
+		})
+		return true
+	}
+	if err := quick.Check(f, qconfig()); err != nil {
+		t.Error(err)
+	}
+}
+
+// Ensure that a Tx cursor can iterate over subbuckets.
+func TestCursor_Iterate_BucketsOnly(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
+			b := tx.Bucket([]byte("widgets"))
+			assert.NoError(t, b.CreateBucket([]byte("foo")))
+			assert.NoError(t, b.CreateBucket([]byte("bar")))
+			assert.NoError(t, b.CreateBucket([]byte("baz")))
+			return nil
+		})
+		db.View(func(tx *Tx) error {
+			var names []string
+			c := tx.Bucket([]byte("widgets")).Cursor()
+			for k, v := c.First(); k != nil; k, v = c.Next() {
+				names = append(names, string(k))
+				assert.Nil(t, v)
+			}
+			assert.Equal(t, names, []string{"bar", "baz", "foo"})
+			return nil
+		})
+	})
+}
+
+// Ensure that a Tx cursor can reverse iterate over subbuckets.
+func TestCursor_Iterate_BucketsOnly_Reverse(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
+			b := tx.Bucket([]byte("widgets"))
+			assert.NoError(t, b.CreateBucket([]byte("foo")))
+			assert.NoError(t, b.CreateBucket([]byte("bar")))
+			assert.NoError(t, b.CreateBucket([]byte("baz")))
+			return nil
+		})
+		db.View(func(tx *Tx) error {
+			var names []string
+			c := tx.Bucket([]byte("widgets")).Cursor()
+			for k, v := c.Last(); k != nil; k, v = c.Prev() {
+				names = append(names, string(k))
+				assert.Nil(t, v)
+			}
+			assert.Equal(t, names, []string{"foo", "baz", "bar"})
+			return nil
+		})
+	})
+}
diff --git a/db.go b/db.go
index a76639d..c9611f9 100644
--- a/db.go
+++ b/db.go
@@ -45,6 +45,7 @@ type DB struct {
 	rwlock   sync.Mutex   // Allows only one writer at a time.
 	metalock sync.Mutex   // Protects meta page access.
 	mmaplock sync.RWMutex // Protects mmap access during remapping.
+	statlock sync.RWMutex // Protects stats access.
 
 	ops struct {
 		writeAt func(b []byte, off int64) (n int, err error)
@@ -133,7 +134,7 @@ func (db *DB) mmap(minsz int) error {
 
 	// Dereference all mmap references before unmapping.
 	if db.rwtx != nil {
-		db.rwtx.dereference()
+		db.rwtx.root.dereference()
 	}
 
 	// Unmap existing data before continuing.
@@ -224,7 +225,7 @@ func (db *DB) init() error {
 		m.pageSize = uint32(db.pageSize)
 		m.version = version
 		m.freelist = 2
-		m.buckets = 3
+		m.root = bucket{root: 3}
 		m.pgid = 4
 		m.txid = txid(i)
 	}
@@ -238,7 +239,7 @@ func (db *DB) init() error {
 	// Write an empty leaf page at page 4.
 	p = db.pageInBuffer(buf[:], pgid(3))
 	p.id = pgid(3)
-	p.flags = bucketsPageFlag
+	p.flags = leafPageFlag
 	p.count = 0
 
 	// Write the buffer to our data file.
@@ -305,16 +306,18 @@ func (db *DB) Begin(writable bool) (*Tx, error) {
 }
 
 func (db *DB) beginTx() (*Tx, error) {
-	db.metalock.Lock()
-	defer db.metalock.Unlock()
-
 	// Obtain a read-only lock on the mmap. When the mmap is remapped it will
 	// obtain a write lock so all transactions must finish before it can be
 	// remapped.
 	db.mmaplock.RLock()
 
+	// Lock the meta pages while we initialize the transaction.
+	db.metalock.Lock()
+	defer db.metalock.Unlock()
+
 	// Exit if the database is not open yet.
 	if !db.opened {
+		db.mmaplock.RUnlock()
 		return nil, ErrDatabaseNotOpen
 	}
 
@@ -329,12 +332,15 @@ func (db *DB) beginTx() (*Tx, error) {
 }
 
 func (db *DB) beginRWTx() (*Tx, error) {
-	db.metalock.Lock()
-	defer db.metalock.Unlock()
-
 	// Obtain writer lock. This is released by the transaction when it closes.
+	// This enforces only one writer transaction at a time.
 	db.rwlock.Lock()
 
+	// Once we have the writer lock then we can lock the meta pages so that
+	// we can set up the transaction.
+	db.metalock.Lock()
+	defer db.metalock.Unlock()
+
 	// Exit if the database is not open yet.
 	if !db.opened {
 		db.rwlock.Unlock()
@@ -363,7 +369,6 @@ func (db *DB) beginRWTx() (*Tx, error) {
 // removeTx removes a transaction from the database.
 func (db *DB) removeTx(tx *Tx) {
 	db.metalock.Lock()
-	defer db.metalock.Unlock()
 
 	// Release the read lock on the mmap.
 	db.mmaplock.RUnlock()
@@ -376,8 +381,13 @@ func (db *DB) removeTx(tx *Tx) {
 		}
 	}
 
+	// Unlock the meta pages.
+	db.metalock.Unlock()
+
 	// Merge statistics.
+	db.statlock.Lock()
 	db.stats.TxStats.add(&tx.stats)
+	db.statlock.Unlock()
 }
 
 // Update executes a function within the context of a read-write managed transaction.
@@ -497,8 +507,8 @@ func (db *DB) CopyFile(path string, mode os.FileMode) error {
 // Stats retrieves ongoing performance stats for the database.
 // This is only updated when a transaction closes.
 func (db *DB) Stats() Stats {
-	db.metalock.Lock()
-	defer db.metalock.Unlock()
+	db.statlock.RLock()
+	defer db.statlock.RUnlock()
 	return db.stats
 }
 
@@ -510,40 +520,14 @@ func (db *DB) Check() error {
 
 		// Track every reachable page.
 		reachable := make(map[pgid]*page)
-		reachable[0] = tx.page(0) // meta0
-		reachable[1] = tx.page(1) // meta1
-		for i := uint32(0); i <= tx.page(tx.meta.buckets).overflow; i++ {
-			reachable[tx.meta.buckets+pgid(i)] = tx.page(tx.meta.buckets)
-		}
-		for i := uint32(0); i <= tx.page(tx.meta.freelist).overflow; i++ {
-			reachable[tx.meta.freelist+pgid(i)] = tx.page(tx.meta.freelist)
+		reachable[0] = db.page(0) // meta0
+		reachable[1] = db.page(1) // meta1
+		for i := uint32(0); i <= db.page(tx.meta.freelist).overflow; i++ {
+			reachable[tx.meta.freelist+pgid(i)] = db.page(tx.meta.freelist)
 		}
 
-		// Check each reachable page within each bucket.
-		for _, bucket := range tx.Buckets() {
-			// warnf("[bucket] %s", bucket.name)
-			tx.forEachPage(bucket.root, 0, func(p *page, _ int) {
-				// Ensure each page is only referenced once.
-				for i := pgid(0); i <= pgid(p.overflow); i++ {
-					var id = p.id + i
-					if _, ok := reachable[id]; ok {
-						errors = append(errors, fmt.Errorf("page %d: multiple references", int(id)))
-					}
-					reachable[id] = p
-				}
-
-				// Retrieve page info.
-				info, err := tx.Page(int(p.id))
-				// warnf("[page] %d + %d (%s)", p.id, p.overflow, info.Type)
-				if err != nil {
-					errors = append(errors, err)
-				} else if info == nil {
-					errors = append(errors, fmt.Errorf("page %d: out of bounds: %d", int(p.id), int(tx.meta.pgid)))
-				} else if info.Type != "branch" && info.Type != "leaf" {
-					errors = append(errors, fmt.Errorf("page %d: invalid type: %s", int(p.id), info.Type))
-				}
-			})
-		}
+		// Recursively check buckets.
+		db.checkBucket(&tx.root, reachable, &errors)
 
 		// Ensure all pages below high water mark are either reachable or freed.
 		for i := pgid(0); i < tx.meta.pgid; i++ {
@@ -553,8 +537,6 @@ func (db *DB) Check() error {
 			}
 		}
 
-		// TODO(benbjohnson): Ensure that only one buckets page exists.
-
 		if len(errors) > 0 {
 			return errors
 		}
@@ -563,6 +545,39 @@ func (db *DB) Check() error {
 	})
 }
 
+func (db *DB) checkBucket(b *Bucket, reachable map[pgid]*page, errors *ErrorList) {
+	// Check every page used by this bucket.
+	b.tx.forEachPage(b.root, 0, func(p *page, _ int) {
+		// Ensure each page is only referenced once.
+		for i := pgid(0); i <= pgid(p.overflow); i++ {
+			var id = p.id + i
+			if _, ok := reachable[id]; ok {
+				*errors = append(*errors, fmt.Errorf("page %d: multiple references", int(id)))
+			}
+			reachable[id] = p
+		}
+
+		// Retrieve page info.
+		info, err := b.tx.Page(int(p.id))
+		// warnf("[page] %d + %d (%s)", p.id, p.overflow, info.Type)
+		if err != nil {
+			*errors = append(*errors, err)
+		} else if info == nil {
+			*errors = append(*errors, fmt.Errorf("page %d: out of bounds: %d", int(p.id), int(b.tx.meta.pgid)))
+		} else if info.Type != "branch" && info.Type != "leaf" {
+			*errors = append(*errors, fmt.Errorf("page %d: invalid type: %s", int(p.id), info.Type))
+		}
+	})
+
+	// Check each bucket within this bucket.
+	_ = b.ForEach(func(k, v []byte) error {
+		if child := b.Bucket(k); child != nil {
+			db.checkBucket(child, reachable, errors)
+		}
+		return nil
+	})
+}
+
 // page retrieves a page reference from the mmap based on the current page size.
 func (db *DB) page(id pgid) *page {
 	pos := id * pgid(db.pageSize)
diff --git a/db_test.go b/db_test.go
index 10f3220..aa72461 100644
--- a/db_test.go
+++ b/db_test.go
@@ -5,8 +5,11 @@ import (
 	"flag"
 	"fmt"
 	"io/ioutil"
+	"math/rand"
 	"os"
 	"regexp"
+	"strconv"
+	"strings"
 	"testing"
 	"time"
 	"unsafe"
@@ -31,14 +34,14 @@ func TestOpen(t *testing.T) {
 }
 
 // Ensure that opening a database with a bad path returns an error.
-func TestOpenBadPath(t *testing.T) {
+func TestOpen_BadPath(t *testing.T) {
 	db, err := Open("/../bad-path", 0666)
 	assert.Error(t, err)
 	assert.Nil(t, db)
 }
 
 // Ensure that a database can be opened without error.
-func TestDBOpen(t *testing.T) {
+func TestDB_Open(t *testing.T) {
 	withTempPath(func(path string) {
 		db, err := Open(path, 0666)
 		assert.NotNil(t, db)
@@ -49,7 +52,7 @@ func TestDBOpen(t *testing.T) {
 }
 
 // Ensure that a re-opened database is consistent.
-func TestOpenCheck(t *testing.T) {
+func TestOpen_Check(t *testing.T) {
 	withTempPath(func(path string) {
 		db, err := Open(path, 0666)
 		assert.NoError(t, err)
@@ -64,7 +67,7 @@ func TestOpenCheck(t *testing.T) {
 }
 
 // Ensure that the database returns an error if the file handle cannot be open.
-func TestDBOpenFileError(t *testing.T) {
+func TestDB_Open_FileError(t *testing.T) {
 	withTempPath(func(path string) {
 		_, err := Open(path+"/youre-not-my-real-parent", 0666)
 		if err, _ := err.(*os.PathError); assert.Error(t, err) {
@@ -75,12 +78,12 @@ func TestDBOpenFileError(t *testing.T) {
 }
 
 // Ensure that write errors to the meta file handler during initialization are returned.
-func TestDBMetaInitWriteError(t *testing.T) {
+func TestDB_Open_MetaInitWriteError(t *testing.T) {
 	t.Skip("pending")
 }
 
 // Ensure that a database that is too small returns an error.
-func TestDBFileTooSmall(t *testing.T) {
+func TestDB_Open_FileTooSmall(t *testing.T) {
 	withTempPath(func(path string) {
 		db, err := Open(path, 0666)
 		assert.NoError(t, err)
@@ -95,7 +98,7 @@ func TestDBFileTooSmall(t *testing.T) {
 }
 
 // Ensure that corrupt meta0 page errors get returned.
-func TestDBCorruptMeta0(t *testing.T) {
+func TestDB_Open_CorruptMeta0(t *testing.T) {
 	withTempPath(func(path string) {
 		var m meta
 		m.magic = magic
@@ -119,16 +122,16 @@ func TestDBCorruptMeta0(t *testing.T) {
 }
 
 // Ensure that a corrupt meta page checksum causes the open to fail.
-func TestDBMetaChecksumError(t *testing.T) {
+func TestDB_Open_MetaChecksumError(t *testing.T) {
 	for i := 0; i < 2; i++ {
 		withTempPath(func(path string) {
 			db, err := Open(path, 0600)
 			pageSize := db.pageSize
 			db.Update(func(tx *Tx) error {
-				return tx.CreateBucket("widgets")
+				return tx.CreateBucket([]byte("widgets"))
 			})
 			db.Update(func(tx *Tx) error {
-				return tx.CreateBucket("woojits")
+				return tx.CreateBucket([]byte("woojits"))
 			})
 			db.Close()
 
@@ -152,7 +155,7 @@ func TestDBMetaChecksumError(t *testing.T) {
 }
 
 // Ensure that a database cannot open a transaction when it's not open.
-func TestDBTxErrDatabaseNotOpen(t *testing.T) {
+func TestDB_Begin_DatabaseNotOpen(t *testing.T) {
 	var db DB
 	tx, err := db.Begin(false)
 	assert.Nil(t, tx)
@@ -160,7 +163,7 @@ func TestDBTxErrDatabaseNotOpen(t *testing.T) {
 }
 
 // Ensure that a read-write transaction can be retrieved.
-func TestDBBeginRW(t *testing.T) {
+func TestDB_BeginRW(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		tx, err := db.Begin(true)
 		assert.NotNil(t, tx)
@@ -172,7 +175,7 @@ func TestDBBeginRW(t *testing.T) {
 }
 
 // Ensure that opening a transaction while the DB is closed returns an error.
-func TestDBRWTxOpenWithClosedDB(t *testing.T) {
+func TestDB_BeginRW_Closed(t *testing.T) {
 	var db DB
 	tx, err := db.Begin(true)
 	assert.Equal(t, err, ErrDatabaseNotOpen)
@@ -180,11 +183,11 @@ func TestDBRWTxOpenWithClosedDB(t *testing.T) {
 }
 
 // Ensure a database can provide a transactional block.
-func TestDBTxBlock(t *testing.T) {
+func TestDB_Update(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		err := db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			b := tx.Bucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
 			b.Put([]byte("foo"), []byte("bar"))
 			b.Put([]byte("baz"), []byte("bat"))
 			b.Delete([]byte("foo"))
@@ -192,8 +195,8 @@ func TestDBTxBlock(t *testing.T) {
 		})
 		assert.NoError(t, err)
 		err = db.View(func(tx *Tx) error {
-			assert.Nil(t, tx.Bucket("widgets").Get([]byte("foo")))
-			assert.Equal(t, []byte("bat"), tx.Bucket("widgets").Get([]byte("baz")))
+			assert.Nil(t, tx.Bucket([]byte("widgets")).Get([]byte("foo")))
+			assert.Equal(t, []byte("bat"), tx.Bucket([]byte("widgets")).Get([]byte("baz")))
 			return nil
 		})
 		assert.NoError(t, err)
@@ -201,20 +204,20 @@ func TestDBTxBlock(t *testing.T) {
 }
 
 // Ensure a closed database returns an error while running a transaction block
-func TestDBTxBlockWhileClosed(t *testing.T) {
+func TestDB_Update_Closed(t *testing.T) {
 	var db DB
 	err := db.Update(func(tx *Tx) error {
-		tx.CreateBucket("widgets")
+		tx.CreateBucket([]byte("widgets"))
 		return nil
 	})
 	assert.Equal(t, err, ErrDatabaseNotOpen)
 }
 
 // Ensure a panic occurs while trying to commit a managed transaction.
-func TestDBTxBlockWithManualCommitAndRollback(t *testing.T) {
+func TestDB_Update_ManualCommitAndRollback(t *testing.T) {
 	var db DB
 	db.Update(func(tx *Tx) error {
-		tx.CreateBucket("widgets")
+		tx.CreateBucket([]byte("widgets"))
 		assert.Panics(t, func() { tx.Commit() })
 		assert.Panics(t, func() { tx.Rollback() })
 		return nil
@@ -226,37 +229,58 @@ func TestDBTxBlockWithManualCommitAndRollback(t *testing.T) {
 	})
 }
 
+// Ensure a database can return an error through a read-only transactional block.
+func TestDB_View_Error(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		err := db.View(func(tx *Tx) error {
+			return errors.New("xxx")
+		})
+		assert.Equal(t, errors.New("xxx"), err)
+	})
+}
+
 // Ensure that the database can be copied to a file path.
-func TestDBCopyFile(t *testing.T) {
+func TestDB_CopyFile(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
+		var dest = tempfile()
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
-			tx.Bucket("widgets").Put([]byte("baz"), []byte("bat"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
+			tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte("bat"))
 			return nil
 		})
-		assert.NoError(t, os.RemoveAll("/tmp/bolt.copyfile.db"))
-		assert.NoError(t, db.CopyFile("/tmp/bolt.copyfile.db", 0666))
+		assert.NoError(t, db.CopyFile(dest, 0600))
 
-		db2, err := Open("/tmp/bolt.copyfile.db", 0666)
+		db2, err := Open(dest, 0600)
 		assert.NoError(t, err)
 		defer db2.Close()
 
 		db2.View(func(tx *Tx) error {
-			assert.Equal(t, []byte("bar"), tx.Bucket("widgets").Get([]byte("foo")))
-			assert.Equal(t, []byte("bat"), tx.Bucket("widgets").Get([]byte("baz")))
+			assert.Equal(t, []byte("bar"), tx.Bucket([]byte("widgets")).Get([]byte("foo")))
+			assert.Equal(t, []byte("bat"), tx.Bucket([]byte("widgets")).Get([]byte("baz")))
 			return nil
 		})
 	})
 }
 
 // Ensure that an error is returned when a database write fails.
-func TestDBWriteFail(t *testing.T) {
+func TestDB_Commit_WriteFail(t *testing.T) {
 	t.Skip("pending") // TODO(benbjohnson)
 }
 
+// Ensure that DB stats can be returned.
+func TestDB_Stats(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			return tx.CreateBucket([]byte("widgets"))
+		})
+		stats := db.Stats()
+		assert.Equal(t, 3, stats.TxStats.PageCount)
+	})
+}
+
 // Ensure that the mmap grows appropriately.
-func TestDBMmapSize(t *testing.T) {
+func TestDB_mmapSize(t *testing.T) {
 	db := &DB{pageSize: 4096}
 	assert.Equal(t, db.mmapSize(0), minMmapSize)
 	assert.Equal(t, db.mmapSize(16384), minMmapSize)
@@ -268,15 +292,15 @@ func TestDBMmapSize(t *testing.T) {
 }
 
 // Ensure that database pages are in expected order and type.
-func TestDBConsistency(t *testing.T) {
+func TestDB_Consistency(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			return tx.CreateBucket("widgets")
+			return tx.CreateBucket([]byte("widgets"))
 		})
 
 		for i := 0; i < 10; i++ {
 			db.Update(func(tx *Tx) error {
-				assert.NoError(t, tx.Bucket("widgets").Put([]byte("foo"), []byte("bar")))
+				assert.NoError(t, tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar")))
 				return nil
 			})
 		}
@@ -297,7 +321,7 @@ func TestDBConsistency(t *testing.T) {
 				assert.Equal(t, "freelist", p.Type)
 			}
 			if p, _ := tx.Page(5); assert.NotNil(t, p) {
-				assert.Equal(t, "buckets", p.Type)
+				assert.Equal(t, "leaf", p.Type) // root leaf
 			}
 			if p, _ := tx.Page(6); assert.NotNil(t, p) {
 				assert.Equal(t, "leaf", p.Type)
@@ -313,20 +337,187 @@ func TestDBConsistency(t *testing.T) {
 }
 
 // Ensure that a database can return a string representation of itself.
-func TestDBString(t *testing.T) {
-	db := &DB{path: "/tmp/foo"}
-	assert.Equal(t, db.String(), `DB<"/tmp/foo">`)
-	assert.Equal(t, db.GoString(), `bolt.DB{path:"/tmp/foo"}`)
+func TestDB_String(t *testing.T) {
+	db := &DB{path: "/foo/bar"}
+	assert.Equal(t, db.String(), `DB<"/foo/bar">`)
+	assert.Equal(t, db.GoString(), `bolt.DB{path:"/foo/bar"}`)
 }
 
-// withTempPath executes a function with a database reference.
-func withTempPath(fn func(string)) {
+// Ensure that DB stats can be substracted from one another.
+func TestDBStats_Sub(t *testing.T) {
+	var a, b Stats
+	a.TxStats.PageCount = 3
+	b.TxStats.PageCount = 10
+	diff := b.Sub(&a)
+	assert.Equal(t, 7, diff.TxStats.PageCount)
+}
+
+// Benchmark the performance of single put transactions in random order.
+func BenchmarkDB_Put_Sequential(b *testing.B) {
+	value := []byte(strings.Repeat("0", 64))
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			return tx.CreateBucket([]byte("widgets"))
+		})
+		for i := 0; i < b.N; i++ {
+			db.Update(func(tx *Tx) error {
+				return tx.Bucket([]byte("widgets")).Put([]byte(strconv.Itoa(i)), value)
+			})
+		}
+	})
+}
+
+// Benchmark the performance of single put transactions in random order.
+func BenchmarkDB_Put_Random(b *testing.B) {
+	indexes := rand.Perm(b.N)
+	value := []byte(strings.Repeat("0", 64))
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			return tx.CreateBucket([]byte("widgets"))
+		})
+		for i := 0; i < b.N; i++ {
+			db.Update(func(tx *Tx) error {
+				return tx.Bucket([]byte("widgets")).Put([]byte(strconv.Itoa(indexes[i])), value)
+			})
+		}
+	})
+}
+
+func ExampleDB_Update() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Execute several commands within a write transaction.
+	err := db.Update(func(tx *Tx) error {
+		if err := tx.CreateBucket([]byte("widgets")); err != nil {
+			return err
+		}
+		b := tx.Bucket([]byte("widgets"))
+		if err := b.Put([]byte("foo"), []byte("bar")); err != nil {
+			return err
+		}
+		return nil
+	})
+
+	// If our transactional block didn't return an error then our data is saved.
+	if err == nil {
+		db.View(func(tx *Tx) error {
+			value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
+			fmt.Printf("The value of 'foo' is: %s\n", string(value))
+			return nil
+		})
+	}
+
+	// Output:
+	// The value of 'foo' is: bar
+}
+
+func ExampleDB_View() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Insert data into a bucket.
+	db.Update(func(tx *Tx) error {
+		tx.CreateBucket([]byte("people"))
+		b := tx.Bucket([]byte("people"))
+		b.Put([]byte("john"), []byte("doe"))
+		b.Put([]byte("susy"), []byte("que"))
+		return nil
+	})
+
+	// Access data from within a read-only transactional block.
+	db.View(func(tx *Tx) error {
+		v := tx.Bucket([]byte("people")).Get([]byte("john"))
+		fmt.Printf("John's last name is %s.\n", string(v))
+		return nil
+	})
+
+	// Output:
+	// John's last name is doe.
+}
+
+func ExampleDB_Begin_ReadOnly() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Create a bucket.
+	db.Update(func(tx *Tx) error {
+		return tx.CreateBucket([]byte("widgets"))
+	})
+
+	// Create several keys in a transaction.
+	tx, _ := db.Begin(true)
+	b := tx.Bucket([]byte("widgets"))
+	b.Put([]byte("john"), []byte("blue"))
+	b.Put([]byte("abby"), []byte("red"))
+	b.Put([]byte("zephyr"), []byte("purple"))
+	tx.Commit()
+
+	// Iterate over the values in sorted key order.
+	tx, _ = db.Begin(false)
+	c := tx.Bucket([]byte("widgets")).Cursor()
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		fmt.Printf("%s likes %s\n", string(k), string(v))
+	}
+	tx.Rollback()
+
+	// Output:
+	// abby likes red
+	// john likes blue
+	// zephyr likes purple
+}
+
+func ExampleDB_CopyFile() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Create a bucket and a key.
+	db.Update(func(tx *Tx) error {
+		tx.CreateBucket([]byte("widgets"))
+		tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
+		return nil
+	})
+
+	// Copy the database to another file.
+	toFile := tempfile()
+	db.CopyFile(toFile, 0666)
+	defer os.Remove(toFile)
+
+	// Open the cloned database.
+	db2, _ := Open(toFile, 0666)
+	defer db2.Close()
+
+	// Ensure that the key exists in the copy.
+	db2.View(func(tx *Tx) error {
+		value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
+		fmt.Printf("The value for 'foo' in the clone is: %s\n", string(value))
+		return nil
+	})
+
+	// Output:
+	// The value for 'foo' in the clone is: bar
+}
+
+// tempfile returns a temporary file path.
+func tempfile() string {
 	f, _ := ioutil.TempFile("", "bolt-")
-	path := f.Name()
 	f.Close()
-	os.Remove(path)
-	defer os.RemoveAll(path)
+	os.Remove(f.Name())
+	return f.Name()
+}
 
+// withTempPath executes a function with a database reference.
+func withTempPath(fn func(string)) {
+	path := tempfile()
+	defer os.RemoveAll(path)
 	fn(path)
 }
 
@@ -354,7 +545,8 @@ func withOpenDB(fn func(*DB, string)) {
 func mustCheck(db *DB) {
 	if err := db.Check(); err != nil {
 		// Copy db off first.
-		db.CopyFile("/tmp/check.db", 0600)
+		var path = tempfile()
+		db.CopyFile(path, 0600)
 
 		if errors, ok := err.(ErrorList); ok {
 			for _, err := range errors {
@@ -362,7 +554,7 @@ func mustCheck(db *DB) {
 			}
 		}
 		warn(err)
-		panic("check failure: see /tmp/check.db")
+		panic("check failure: " + path)
 	}
 }
 
@@ -391,3 +583,11 @@ func logStats(db *DB) {
 func truncDuration(d time.Duration) string {
 	return regexp.MustCompile(`^(\d+)(\.\d+)`).ReplaceAllString(d.String(), "$1")
 }
+
+// copyAndFailNow copies a database to a new location and then fails then test.
+func copyAndFailNow(t *testing.T, db *DB) {
+	path := tempfile()
+	db.CopyFile(path, 0600)
+	fmt.Println("db copied to: ", path)
+	t.FailNow()
+}
diff --git a/example_test.go b/example_test.go
deleted file mode 100644
index 3e3758e..0000000
--- a/example_test.go
+++ /dev/null
@@ -1,251 +0,0 @@
-package bolt
-
-import (
-	"fmt"
-	"os"
-)
-
-func init() {
-	os.RemoveAll("/tmp/bolt")
-	os.MkdirAll("/tmp/bolt", 0777)
-}
-
-func ExampleDB_Update() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/db_do.db", 0666)
-	defer db.Close()
-
-	// Execute several commands within a write transaction.
-	err := db.Update(func(tx *Tx) error {
-		if err := tx.CreateBucket("widgets"); err != nil {
-			return err
-		}
-		b := tx.Bucket("widgets")
-		if err := b.Put([]byte("foo"), []byte("bar")); err != nil {
-			return err
-		}
-		return nil
-	})
-
-	// If our transactional block didn't return an error then our data is saved.
-	if err == nil {
-		db.View(func(tx *Tx) error {
-			value := tx.Bucket("widgets").Get([]byte("foo"))
-			fmt.Printf("The value of 'foo' is: %s\n", string(value))
-			return nil
-		})
-	}
-
-	// Output:
-	// The value of 'foo' is: bar
-}
-
-func ExampleDB_View() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/db_with.db", 0666)
-	defer db.Close()
-
-	// Insert data into a bucket.
-	db.Update(func(tx *Tx) error {
-		tx.CreateBucket("people")
-		tx.Bucket("people").Put([]byte("john"), []byte("doe"))
-		tx.Bucket("people").Put([]byte("susy"), []byte("que"))
-		return nil
-	})
-
-	// Access data from within a read-only transactional block.
-	db.View(func(tx *Tx) error {
-		v := tx.Bucket("people").Get([]byte("john"))
-		fmt.Printf("John's last name is %s.\n", string(v))
-		return nil
-	})
-
-	// Output:
-	// John's last name is doe.
-}
-
-func ExampleTx_Put() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/db_put.db", 0666)
-	defer db.Close()
-
-	// Start a write transaction.
-	db.Update(func(tx *Tx) error {
-		// Create a bucket.
-		tx.CreateBucket("widgets")
-
-		// Set the value "bar" for the key "foo".
-		tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
-		return nil
-	})
-
-	// Read value back in a different read-only transaction.
-	db.Update(func(tx *Tx) error {
-		value := tx.Bucket("widgets").Get([]byte("foo"))
-		fmt.Printf("The value of 'foo' is: %s\n", string(value))
-		return nil
-	})
-
-	// Output:
-	// The value of 'foo' is: bar
-}
-
-func ExampleTx_Delete() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/db_delete.db", 0666)
-	defer db.Close()
-
-	// Start a write transaction.
-	db.Update(func(tx *Tx) error {
-		// Create a bucket.
-		tx.CreateBucket("widgets")
-		b := tx.Bucket("widgets")
-
-		// Set the value "bar" for the key "foo".
-		b.Put([]byte("foo"), []byte("bar"))
-
-		// Retrieve the key back from the database and verify it.
-		value := b.Get([]byte("foo"))
-		fmt.Printf("The value of 'foo' was: %s\n", string(value))
-		return nil
-	})
-
-	// Delete the key in a different write transaction.
-	db.Update(func(tx *Tx) error {
-		return tx.Bucket("widgets").Delete([]byte("foo"))
-	})
-
-	// Retrieve the key again.
-	db.View(func(tx *Tx) error {
-		value := tx.Bucket("widgets").Get([]byte("foo"))
-		if value == nil {
-			fmt.Printf("The value of 'foo' is now: nil\n")
-		}
-		return nil
-	})
-
-	// Output:
-	// The value of 'foo' was: bar
-	// The value of 'foo' is now: nil
-}
-
-func ExampleTx_ForEach() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/tx_foreach.db", 0666)
-	defer db.Close()
-
-	// Insert data into a bucket.
-	db.Update(func(tx *Tx) error {
-		tx.CreateBucket("animals")
-		b := tx.Bucket("animals")
-		b.Put([]byte("dog"), []byte("fun"))
-		b.Put([]byte("cat"), []byte("lame"))
-		b.Put([]byte("liger"), []byte("awesome"))
-
-		// Iterate over items in sorted key order.
-		b.ForEach(func(k, v []byte) error {
-			fmt.Printf("A %s is %s.\n", string(k), string(v))
-			return nil
-		})
-		return nil
-	})
-
-	// Output:
-	// A cat is lame.
-	// A dog is fun.
-	// A liger is awesome.
-}
-
-func ExampleBegin_ReadOnly() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/tx.db", 0666)
-	defer db.Close()
-
-	// Create a bucket.
-	db.Update(func(tx *Tx) error {
-		return tx.CreateBucket("widgets")
-	})
-
-	// Create several keys in a transaction.
-	tx, _ := db.Begin(true)
-	b := tx.Bucket("widgets")
-	b.Put([]byte("john"), []byte("blue"))
-	b.Put([]byte("abby"), []byte("red"))
-	b.Put([]byte("zephyr"), []byte("purple"))
-	tx.Commit()
-
-	// Iterate over the values in sorted key order.
-	tx, _ = db.Begin(false)
-	c := tx.Bucket("widgets").Cursor()
-	for k, v := c.First(); k != nil; k, v = c.Next() {
-		fmt.Printf("%s likes %s\n", string(k), string(v))
-	}
-	tx.Rollback()
-
-	// Output:
-	// abby likes red
-	// john likes blue
-	// zephyr likes purple
-}
-
-func ExampleTx_rollback() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/tx_rollback.db", 0666)
-	defer db.Close()
-
-	// Create a bucket.
-	db.Update(func(tx *Tx) error {
-		return tx.CreateBucket("widgets")
-	})
-
-	// Set a value for a key.
-	db.Update(func(tx *Tx) error {
-		return tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
-	})
-
-	// Update the key but rollback the transaction so it never saves.
-	tx, _ := db.Begin(true)
-	b := tx.Bucket("widgets")
-	b.Put([]byte("foo"), []byte("baz"))
-	tx.Rollback()
-
-	// Ensure that our original value is still set.
-	db.View(func(tx *Tx) error {
-		value := tx.Bucket("widgets").Get([]byte("foo"))
-		fmt.Printf("The value for 'foo' is still: %s\n", string(value))
-		return nil
-	})
-
-	// Output:
-	// The value for 'foo' is still: bar
-}
-
-func ExampleDB_CopyFile() {
-	// Open the database.
-	db, _ := Open("/tmp/bolt/db_copy.db", 0666)
-	defer db.Close()
-
-	// Create a bucket and a key.
-	db.Update(func(tx *Tx) error {
-		tx.CreateBucket("widgets")
-		tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
-		return nil
-	})
-
-	// Copy the database to another file.
-	db.CopyFile("/tmp/bolt/db_copy_2.db", 0666)
-
-	// Open the cloned database.
-	db2, _ := Open("/tmp/bolt/db_copy_2.db", 0666)
-	defer db2.Close()
-
-	// Ensure that the key exists in the copy.
-	db2.View(func(tx *Tx) error {
-		value := tx.Bucket("widgets").Get([]byte("foo"))
-		fmt.Printf("The value for 'foo' in the clone is: %s\n", string(value))
-		return nil
-	})
-
-	// Output:
-	// The value for 'foo' in the clone is: bar
-}
diff --git a/freelist.go b/freelist.go
index cb58a54..ebe2810 100644
--- a/freelist.go
+++ b/freelist.go
@@ -62,6 +62,8 @@ func (f *freelist) free(txid txid, p *page) {
 		ids = append(ids, p.id+pgid(i))
 	}
 	f.pending[txid] = ids
+
+	// DEBUG ONLY: f.check()
 }
 
 // release moves all page ids for a transaction id (or older) to the freelist.
@@ -109,6 +111,29 @@ func (f *freelist) write(p *page) {
 	copy(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[:], ids)
 }
 
+// check verifies there are no double free pages.
+// This is slow so it should only be used while debugging.
+// If errors are found then a panic invoked.
+/*
+func (f *freelist) check() {
+	var lookup = make(map[pgid]txid)
+	for _, id := range f.ids {
+		if _, ok := lookup[id]; ok {
+			panic(fmt.Sprintf("page %d already freed", id))
+		}
+		lookup[id] = 0
+	}
+	for txid, m := range f.pending {
+		for _, id := range m {
+			if _, ok := lookup[id]; ok {
+				panic(fmt.Sprintf("tx %d: page %d already freed in tx %d", txid, id, lookup[id]))
+			}
+			lookup[id] = txid
+		}
+	}
+}
+*/
+
 type reverseSortedPgids []pgid
 
 func (s reverseSortedPgids) Len() int           { return len(s) }
diff --git a/freelist_test.go b/freelist_test.go
index 8421392..2b321a4 100644
--- a/freelist_test.go
+++ b/freelist_test.go
@@ -8,21 +8,21 @@ import (
 )
 
 // Ensure that a page is added to a transaction's freelist.
-func TestFreelistFree(t *testing.T) {
+func TestFreelist_free(t *testing.T) {
 	f := &freelist{pending: make(map[txid][]pgid)}
 	f.free(100, &page{id: 12})
 	assert.Equal(t, f.pending[100], []pgid{12})
 }
 
 // Ensure that a page and its overflow is added to a transaction's freelist.
-func TestFreelistFreeOverflow(t *testing.T) {
+func TestFreelist_free_overflow(t *testing.T) {
 	f := &freelist{pending: make(map[txid][]pgid)}
 	f.free(100, &page{id: 12, overflow: 3})
 	assert.Equal(t, f.pending[100], []pgid{12, 13, 14, 15})
 }
 
 // Ensure that a transaction's free pages can be released.
-func TestFreelistRelease(t *testing.T) {
+func TestFreelist_release(t *testing.T) {
 	f := &freelist{pending: make(map[txid][]pgid)}
 	f.free(100, &page{id: 12, overflow: 1})
 	f.free(100, &page{id: 9})
@@ -35,7 +35,7 @@ func TestFreelistRelease(t *testing.T) {
 }
 
 // Ensure that a freelist can find contiguous blocks of pages.
-func TestFreelistAllocate(t *testing.T) {
+func TestFreelist_allocate(t *testing.T) {
 	f := &freelist{ids: []pgid{18, 13, 12, 9, 7, 6, 5, 4, 3}}
 	assert.Equal(t, f.allocate(2), pgid(12))
 	assert.Equal(t, f.allocate(1), pgid(18))
@@ -48,7 +48,7 @@ func TestFreelistAllocate(t *testing.T) {
 }
 
 // Ensure that a freelist can deserialize from a freelist page.
-func TestFreelistRead(t *testing.T) {
+func TestFreelist_read(t *testing.T) {
 	// Create a page.
 	var buf [4096]byte
 	page := (*page)(unsafe.Pointer(&buf[0]))
@@ -71,7 +71,7 @@ func TestFreelistRead(t *testing.T) {
 }
 
 // Ensure that a freelist can serialize into a freelist page.
-func TestFreelistWrite(t *testing.T) {
+func TestFreelist_write(t *testing.T) {
 	// Create a freelist and write it to a page.
 	var buf [4096]byte
 	f := &freelist{ids: []pgid{12, 39}, pending: make(map[txid][]pgid)}
diff --git a/functional_test.go b/functional_test.go
deleted file mode 100644
index fdaecbb..0000000
--- a/functional_test.go
+++ /dev/null
@@ -1,144 +0,0 @@
-package bolt
-
-import (
-	"fmt"
-	"os"
-	"sync"
-	"testing"
-	"testing/quick"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-)
-
-// Ensure that multiple threads can use the DB without race detector errors.
-func TestParallelTxs(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test in short mode.")
-	}
-
-	var mutex sync.RWMutex
-
-	err := quick.Check(func(numReaders, batchSize uint, items testdata) bool {
-		// Limit the readers & writers to something reasonable.
-		numReaders = (numReaders % 10) + 1
-		batchSize = (batchSize % 50) + 1
-
-		// warn("")
-		// warn("================================================================")
-		// warn("numReaders:", numReaders, "batchSize", batchSize)
-
-		// Maintain the current dataset.
-		var current testdata
-
-		withOpenDB(func(db *DB, path string) {
-			db.Update(func(tx *Tx) error {
-				return tx.CreateBucket("widgets")
-			})
-
-			// Maintain a set of concurrent readers.
-			var wg sync.WaitGroup
-			var c = make(chan bool, 0)
-			go func() {
-				var readers = make(chan int, numReaders)
-				for {
-					wg.Add(1)
-
-					// Attempt to start a new reader unless we're stopped.
-					select {
-					case readers <- 0:
-					case <-c:
-						wg.Done()
-						return
-					}
-
-					go func() {
-						mutex.RLock()
-						local := make(map[string][]byte)
-						for _, item := range current {
-							local[string(item.Key)] = item.Value
-						}
-						tx, err := db.Begin(false)
-						mutex.RUnlock()
-						if err == ErrDatabaseNotOpen {
-							wg.Done()
-							return
-						} else if !assert.NoError(t, err) {
-							t.FailNow()
-						}
-
-						// Verify all data is in for local data list.
-						for k, v := range local {
-							value := tx.Bucket("widgets").Get([]byte(k))
-							if !assert.NoError(t, err) || !assert.Equal(t, value, v, fmt.Sprintf("reader (%p)", tx)) {
-								tx.Rollback()
-								wg.Done()
-								t.FailNow()
-							}
-						}
-
-						tx.Rollback()
-						wg.Done()
-						<-readers
-					}()
-				}
-			}()
-
-			// Batch insert items.
-			pending := items
-			for {
-				// Determine next batch.
-				currentBatchSize := int(batchSize)
-				if currentBatchSize > len(pending) {
-					currentBatchSize = len(pending)
-				}
-				batchItems := pending[0:currentBatchSize]
-				pending = pending[currentBatchSize:]
-
-				// Start write transaction.
-				tx, err := db.Begin(true)
-				if !assert.NoError(t, err) {
-					t.FailNow()
-				}
-
-				// warnf("[writer] BEGIN (%d)", currentBatchSize)
-
-				// Insert whole batch.
-				b := tx.Bucket("widgets")
-				for _, item := range batchItems {
-					// warnf("[writer] PUT %x: %x", trunc(item.Key, 3), trunc(item.Value, 3))
-					err := b.Put(item.Key, item.Value)
-					if !assert.NoError(t, err) {
-						t.FailNow()
-					}
-				}
-
-				// Commit and update the current list.
-				mutex.Lock()
-				// warnf("[writer] COMMIT\n\n")
-				err = tx.Commit()
-				current = append(current, batchItems...)
-				mutex.Unlock()
-				if !assert.NoError(t, err) {
-					t.FailNow()
-				}
-
-				// If there are no more left then exit.
-				if len(pending) == 0 {
-					break
-				}
-
-				time.Sleep(1 * time.Millisecond)
-			}
-
-			// Notify readers to stop.
-			close(c)
-
-			// Wait for readers to finish.
-			wg.Wait()
-		})
-		return true
-	}, qconfig())
-	assert.NoError(t, err)
-	fmt.Fprint(os.Stderr, "\n")
-}
diff --git a/meta.go b/meta.go
index abb2a93..4212252 100644
--- a/meta.go
+++ b/meta.go
@@ -25,7 +25,7 @@ type meta struct {
 	version  uint32
 	pageSize uint32
 	flags    uint32
-	buckets  pgid
+	root     bucket
 	freelist pgid
 	pgid     pgid
 	txid     txid
diff --git a/meta_test.go b/meta_test.go
index b229078..1a2d6b5 100644
--- a/meta_test.go
+++ b/meta_test.go
@@ -6,13 +6,13 @@ import (
 )
 
 // Ensure that meta with bad magic is invalid.
-func TestMetaValidateMagic(t *testing.T) {
+func TestMeta_validate_magic(t *testing.T) {
 	m := &meta{magic: 0x01234567}
 	assert.Equal(t, m.validate(), ErrInvalid)
 }
 
 // Ensure that meta with a bad version is invalid.
-func TestMetaValidateVersion(t *testing.T) {
+func TestMeta_validate_version(t *testing.T) {
 	m := &meta{magic: magic, version: 200}
 	assert.Equal(t, m.validate(), ErrVersionMismatch)
 }
diff --git a/node.go b/node.go
index 709c0ca..49de144 100644
--- a/node.go
+++ b/node.go
@@ -8,7 +8,7 @@ import (
 
 // node represents an in-memory, deserialized page.
 type node struct {
-	tx         *Tx
+	bucket     *Bucket
 	isLeaf     bool
 	unbalanced bool
 	key        []byte
@@ -45,18 +45,10 @@ func (n *node) pageElementSize() int {
 	return branchPageElementSize
 }
 
-// root returns the root node in the tree.
-func (n *node) root() *node {
-	if n.parent == nil {
-		return n
-	}
-	return n.parent.root()
-}
-
 // childAt returns the child node at a given index.
 func (n *node) childAt(index int) *node {
 	_assert(!n.isLeaf, "invalid childAt(%d) on a leaf node", index)
-	return n.tx.node(n.inodes[index].pgid, n)
+	return n.bucket.node(n.inodes[index].pgid, n)
 }
 
 // childIndex returns the index of a given child node.
@@ -95,7 +87,7 @@ func (n *node) prevSibling() *node {
 }
 
 // put inserts a key/value.
-func (n *node) put(oldKey, newKey, value []byte, pgid pgid) {
+func (n *node) put(oldKey, newKey, value []byte, pgid pgid, flags uint32) {
 	// Find insertion index.
 	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, oldKey) != -1 })
 
@@ -107,6 +99,7 @@ func (n *node) put(oldKey, newKey, value []byte, pgid pgid) {
 	}
 
 	inode := &n.inodes[index]
+	inode.flags = flags
 	inode.key = newKey
 	inode.value = value
 	inode.pgid = pgid
@@ -139,6 +132,7 @@ func (n *node) read(p *page) {
 		inode := &n.inodes[i]
 		if n.isLeaf {
 			elem := p.leafPageElement(uint16(i))
+			inode.flags = elem.flags
 			inode.key = elem.key()
 			inode.value = elem.value()
 		} else {
@@ -173,6 +167,7 @@ func (n *node) write(p *page) {
 		if n.isLeaf {
 			elem := p.leafPageElement(uint16(i))
 			elem.pos = uint32(uintptr(unsafe.Pointer(&b[0])) - uintptr(unsafe.Pointer(elem)))
+			elem.flags = item.flags
 			elem.ksize = uint32(len(item.key))
 			elem.vsize = uint32(len(item.value))
 		} else {
@@ -214,7 +209,7 @@ func (n *node) split(pageSize int) []*node {
 		if len(current.inodes) >= minKeysPerPage && i < len(inodes)-minKeysPerPage && size+elemSize > threshold {
 			size = pageHeaderSize
 			nodes = append(nodes, current)
-			current = &node{tx: n.tx, isLeaf: n.isLeaf}
+			current = &node{bucket: n.bucket, isLeaf: n.isLeaf}
 		}
 
 		size += elemSize
@@ -234,10 +229,10 @@ func (n *node) rebalance() {
 	n.unbalanced = false
 
 	// Update statistics.
-	n.tx.stats.Rebalance++
+	n.bucket.tx.stats.Rebalance++
 
 	// Ignore if node is above threshold (25%) and has enough keys.
-	var threshold = n.tx.db.pageSize / 4
+	var threshold = n.bucket.tx.db.pageSize / 4
 	if n.size() > threshold && len(n.inodes) > n.minKeys() {
 		return
 	}
@@ -247,20 +242,20 @@ func (n *node) rebalance() {
 		// If root node is a branch and only has one node then collapse it.
 		if !n.isLeaf && len(n.inodes) == 1 {
 			// Move child's children up.
-			child := n.tx.nodes[n.inodes[0].pgid]
+			child := n.bucket.nodes[n.inodes[0].pgid]
 			n.isLeaf = child.isLeaf
 			n.inodes = child.inodes[:]
 
 			// Reparent all child nodes being moved.
 			for _, inode := range n.inodes {
-				if child, ok := n.tx.nodes[inode.pgid]; ok {
+				if child, ok := n.bucket.nodes[inode.pgid]; ok {
 					child.parent = n
 				}
 			}
 
 			// Remove old child.
 			child.parent = nil
-			delete(n.tx.nodes, child.pgid)
+			delete(n.bucket.nodes, child.pgid)
 			child.free()
 		}
 
@@ -282,18 +277,18 @@ func (n *node) rebalance() {
 	if target.numChildren() > target.minKeys() {
 		if useNextSibling {
 			// Reparent and move node.
-			if child, ok := n.tx.nodes[target.inodes[0].pgid]; ok {
+			if child, ok := n.bucket.nodes[target.inodes[0].pgid]; ok {
 				child.parent = n
 			}
 			n.inodes = append(n.inodes, target.inodes[0])
 			target.inodes = target.inodes[1:]
 
 			// Update target key on parent.
-			target.parent.put(target.key, target.inodes[0].key, nil, target.pgid)
+			target.parent.put(target.key, target.inodes[0].key, nil, target.pgid, 0)
 			target.key = target.inodes[0].key
 		} else {
 			// Reparent and move node.
-			if child, ok := n.tx.nodes[target.inodes[len(target.inodes)-1].pgid]; ok {
+			if child, ok := n.bucket.nodes[target.inodes[len(target.inodes)-1].pgid]; ok {
 				child.parent = n
 			}
 			n.inodes = append(n.inodes, inode{})
@@ -303,7 +298,7 @@ func (n *node) rebalance() {
 		}
 
 		// Update parent key for node.
-		n.parent.put(n.key, n.inodes[0].key, nil, n.pgid)
+		n.parent.put(n.key, n.inodes[0].key, nil, n.pgid, 0)
 		n.key = n.inodes[0].key
 
 		return
@@ -313,7 +308,7 @@ func (n *node) rebalance() {
 	if useNextSibling {
 		// Reparent all child nodes being moved.
 		for _, inode := range target.inodes {
-			if child, ok := n.tx.nodes[inode.pgid]; ok {
+			if child, ok := n.bucket.nodes[inode.pgid]; ok {
 				child.parent = n
 			}
 		}
@@ -321,12 +316,12 @@ func (n *node) rebalance() {
 		// Copy over inodes from target and remove target.
 		n.inodes = append(n.inodes, target.inodes...)
 		n.parent.del(target.key)
-		delete(n.tx.nodes, target.pgid)
+		delete(n.bucket.nodes, target.pgid)
 		target.free()
 	} else {
 		// Reparent all child nodes being moved.
 		for _, inode := range n.inodes {
-			if child, ok := n.tx.nodes[inode.pgid]; ok {
+			if child, ok := n.bucket.nodes[inode.pgid]; ok {
 				child.parent = target
 			}
 		}
@@ -334,8 +329,8 @@ func (n *node) rebalance() {
 		// Copy over inodes to target and remove node.
 		target.inodes = append(target.inodes, n.inodes...)
 		n.parent.del(n.key)
-		n.parent.put(target.key, target.inodes[0].key, nil, target.pgid)
-		delete(n.tx.nodes, n.pgid)
+		n.parent.put(target.key, target.inodes[0].key, nil, target.pgid, 0)
+		delete(n.bucket.nodes, n.pgid)
 		n.free()
 	}
 
@@ -366,7 +361,7 @@ func (n *node) dereference() {
 // free adds the node's underlying page to the freelist.
 func (n *node) free() {
 	if n.pgid != 0 {
-		n.tx.db.freelist.free(n.tx.id(), n.tx.page(n.pgid))
+		n.bucket.tx.db.freelist.free(n.bucket.tx.id(), n.bucket.tx.page(n.pgid))
 	}
 }
 
@@ -381,6 +376,7 @@ func (s nodesByDepth) Less(i, j int) bool { return s[i].depth > s[j].depth }
 // It can be used to point to elements in a page or point
 // to an element which hasn't been added to a page yet.
 type inode struct {
+	flags uint32
 	pgid  pgid
 	key   []byte
 	value []byte
diff --git a/node_test.go b/node_test.go
index 8555223..e58a544 100644
--- a/node_test.go
+++ b/node_test.go
@@ -8,12 +8,12 @@ import (
 )
 
 // Ensure that a node can insert a key/value.
-func TestNodePut(t *testing.T) {
+func TestNode_put(t *testing.T) {
 	n := &node{inodes: make(inodes, 0)}
-	n.put([]byte("baz"), []byte("baz"), []byte("2"), 0)
-	n.put([]byte("foo"), []byte("foo"), []byte("0"), 0)
-	n.put([]byte("bar"), []byte("bar"), []byte("1"), 0)
-	n.put([]byte("foo"), []byte("foo"), []byte("3"), 0)
+	n.put([]byte("baz"), []byte("baz"), []byte("2"), 0, 0)
+	n.put([]byte("foo"), []byte("foo"), []byte("0"), 0, 0)
+	n.put([]byte("bar"), []byte("bar"), []byte("1"), 0, 0)
+	n.put([]byte("foo"), []byte("foo"), []byte("3"), 0, leafPageFlag)
 	assert.Equal(t, len(n.inodes), 3)
 	assert.Equal(t, n.inodes[0].key, []byte("bar"))
 	assert.Equal(t, n.inodes[0].value, []byte("1"))
@@ -21,10 +21,11 @@ func TestNodePut(t *testing.T) {
 	assert.Equal(t, n.inodes[1].value, []byte("2"))
 	assert.Equal(t, n.inodes[2].key, []byte("foo"))
 	assert.Equal(t, n.inodes[2].value, []byte("3"))
+	assert.Equal(t, n.inodes[2].flags, uint32(leafPageFlag))
 }
 
 // Ensure that a node can deserialize from a leaf page.
-func TestNodeReadLeafPage(t *testing.T) {
+func TestNode_read_LeafPage(t *testing.T) {
 	// Create a page.
 	var buf [4096]byte
 	page := (*page)(unsafe.Pointer(&buf[0]))
@@ -55,12 +56,12 @@ func TestNodeReadLeafPage(t *testing.T) {
 }
 
 // Ensure that a node can serialize into a leaf page.
-func TestNodeWriteLeafPage(t *testing.T) {
+func TestNode_write_LeafPage(t *testing.T) {
 	// Create a node.
 	n := &node{isLeaf: true, inodes: make(inodes, 0)}
-	n.put([]byte("susy"), []byte("susy"), []byte("que"), 0)
-	n.put([]byte("ricki"), []byte("ricki"), []byte("lake"), 0)
-	n.put([]byte("john"), []byte("john"), []byte("johnson"), 0)
+	n.put([]byte("susy"), []byte("susy"), []byte("que"), 0, 0)
+	n.put([]byte("ricki"), []byte("ricki"), []byte("lake"), 0, 0)
+	n.put([]byte("john"), []byte("john"), []byte("johnson"), 0, 0)
 
 	// Write it to a page.
 	var buf [4096]byte
@@ -82,14 +83,14 @@ func TestNodeWriteLeafPage(t *testing.T) {
 }
 
 // Ensure that a node can split into appropriate subgroups.
-func TestNodeSplit(t *testing.T) {
+func TestNode_split(t *testing.T) {
 	// Create a node.
 	n := &node{inodes: make(inodes, 0)}
-	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000003"), []byte("00000003"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000004"), []byte("00000004"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000005"), []byte("00000005"), []byte("0123456701234567"), 0)
+	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000003"), []byte("00000003"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000004"), []byte("00000004"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000005"), []byte("00000005"), []byte("0123456701234567"), 0, 0)
 
 	// Split between 2 & 3.
 	nodes := n.split(100)
@@ -100,11 +101,11 @@ func TestNodeSplit(t *testing.T) {
 }
 
 // Ensure that a page with the minimum number of inodes just returns a single node.
-func TestNodeSplitWithMinKeys(t *testing.T) {
+func TestNode_split_MinKeys(t *testing.T) {
 	// Create a node.
 	n := &node{inodes: make(inodes, 0)}
-	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0)
+	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0, 0)
 
 	// Split.
 	nodes := n.split(20)
@@ -113,14 +114,14 @@ func TestNodeSplitWithMinKeys(t *testing.T) {
 }
 
 // Ensure that a node that has keys that all fit on a page just returns one leaf.
-func TestNodeSplitFitsInPage(t *testing.T) {
+func TestNode_split_SinglePage(t *testing.T) {
 	// Create a node.
 	n := &node{inodes: make(inodes, 0)}
-	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000003"), []byte("00000003"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000004"), []byte("00000004"), []byte("0123456701234567"), 0)
-	n.put([]byte("00000005"), []byte("00000005"), []byte("0123456701234567"), 0)
+	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000003"), []byte("00000003"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000004"), []byte("00000004"), []byte("0123456701234567"), 0, 0)
+	n.put([]byte("00000005"), []byte("00000005"), []byte("0123456701234567"), 0, 0)
 
 	// Split.
 	nodes := n.split(4096)
diff --git a/page.go b/page.go
index 0d46f09..56cf064 100644
--- a/page.go
+++ b/page.go
@@ -19,10 +19,13 @@ const (
 	branchPageFlag   = 0x01
 	leafPageFlag     = 0x02
 	metaPageFlag     = 0x04
-	bucketsPageFlag  = 0x08
 	freelistPageFlag = 0x10
 )
 
+const (
+	bucketLeafFlag = 0x01
+)
+
 type pgid uint64
 
 type page struct {
@@ -41,8 +44,6 @@ func (p *page) typ() string {
 		return "leaf"
 	} else if (p.flags & metaPageFlag) != 0 {
 		return "meta"
-	} else if (p.flags & bucketsPageFlag) != 0 {
-		return "buckets"
 	} else if (p.flags & freelistPageFlag) != 0 {
 		return "freelist"
 	}
diff --git a/page_test.go b/page_test.go
index 976af0d..be90096 100644
--- a/page_test.go
+++ b/page_test.go
@@ -6,16 +6,15 @@ import (
 )
 
 // Ensure that the page type can be returned in human readable format.
-func TestPageTyp(t *testing.T) {
+func TestPage_typ(t *testing.T) {
 	assert.Equal(t, (&page{flags: branchPageFlag}).typ(), "branch")
 	assert.Equal(t, (&page{flags: leafPageFlag}).typ(), "leaf")
 	assert.Equal(t, (&page{flags: metaPageFlag}).typ(), "meta")
-	assert.Equal(t, (&page{flags: bucketsPageFlag}).typ(), "buckets")
 	assert.Equal(t, (&page{flags: freelistPageFlag}).typ(), "freelist")
 	assert.Equal(t, (&page{flags: 20000}).typ(), "unknown<4e20>")
 }
 
 // Ensure that the hexdump debugging function doesn't blow up.
-func TestPageDump(t *testing.T) {
+func TestPage_dump(t *testing.T) {
 	(&page{id: 256}).hexdump(16)
 }
diff --git a/tx.go b/tx.go
index bfdcce1..9f86d5e 100644
--- a/tx.go
+++ b/tx.go
@@ -33,10 +33,8 @@ type Tx struct {
 	managed        bool
 	db             *DB
 	meta           *meta
-	buckets        *buckets
-	nodes          map[pgid]*node
+	root           Bucket
 	pages          map[pgid]*page
-	pending        []*node
 	stats          TxStats
 	commitHandlers []func()
 }
@@ -50,15 +48,14 @@ func (tx *Tx) init(db *DB) {
 	tx.meta = &meta{}
 	db.meta().copy(tx.meta)
 
-	// Read in the buckets page.
-	tx.buckets = &buckets{}
-	tx.buckets.read(tx.page(tx.meta.buckets))
+	// Copy over the root bucket.
+	tx.root = newBucket(tx)
+	tx.root.bucket = &bucket{}
+	*tx.root.bucket = tx.meta.root
 
+	// Increment the transaction id and add a page cache for writable transactions.
 	if tx.writable {
 		tx.pages = make(map[pgid]*page)
-		tx.nodes = make(map[pgid]*node)
-
-		// Increment the transaction id.
 		tx.meta.txid += txid(1)
 	}
 }
@@ -85,95 +82,38 @@ func (tx *Tx) Stats() TxStats {
 
 // Bucket retrieves a bucket by name.
 // Returns nil if the bucket does not exist.
-func (tx *Tx) Bucket(name string) *Bucket {
-	b := tx.buckets.get(name)
-	if b == nil {
-		return nil
-	}
-
-	return &Bucket{
-		bucket: b,
-		name:   name,
-		tx:     tx,
-	}
-}
-
-// Buckets retrieves a list of all buckets.
-func (tx *Tx) Buckets() []*Bucket {
-	buckets := make([]*Bucket, 0, len(tx.buckets.items))
-	for name, b := range tx.buckets.items {
-		bucket := &Bucket{
-			bucket: b,
-			name:   name,
-			tx:     tx,
-		}
-		buckets = append(buckets, bucket)
-	}
-	sort.Sort(bucketsByName(buckets))
-	return buckets
+func (tx *Tx) Bucket(name []byte) *Bucket {
+	return tx.root.Bucket(name)
 }
 
 // CreateBucket creates a new bucket.
 // Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long.
-func (tx *Tx) CreateBucket(name string) error {
-	if tx.db == nil {
-		return ErrTxClosed
-	} else if !tx.writable {
-		return ErrTxNotWritable
-	} else if b := tx.Bucket(name); b != nil {
-		return ErrBucketExists
-	} else if len(name) == 0 {
-		return ErrBucketNameRequired
-	} else if len(name) > MaxBucketNameSize {
-		return ErrBucketNameTooLarge
-	}
-
-	// Create a blank root leaf page.
-	p, err := tx.allocate(1)
-	if err != nil {
-		return err
-	}
-	p.flags = leafPageFlag
-
-	// Add bucket to buckets page.
-	tx.buckets.put(name, &bucket{root: p.id})
-
-	return nil
+func (tx *Tx) CreateBucket(name []byte) error {
+	return tx.root.CreateBucket(name)
 }
 
 // CreateBucketIfNotExists creates a new bucket if it doesn't already exist.
 // Returns an error if the bucket name is blank, or if the bucket name is too long.
-func (tx *Tx) CreateBucketIfNotExists(name string) error {
-	err := tx.CreateBucket(name)
-	if err != nil && err != ErrBucketExists {
-		return err
-	}
-	return nil
+func (tx *Tx) CreateBucketIfNotExists(name []byte) error {
+	return tx.root.CreateBucketIfNotExists(name)
 }
 
 // DeleteBucket deletes a bucket.
-// Returns an error if the bucket cannot be found.
-func (tx *Tx) DeleteBucket(name string) error {
-	if tx.db == nil {
-		return ErrTxClosed
-	} else if !tx.writable {
-		return ErrTxNotWritable
-	}
-
-	b := tx.Bucket(name)
-	if b == nil {
-		return ErrBucketNotFound
-	}
-
-	// Remove from buckets page.
-	tx.buckets.del(name)
+// Returns an error if the bucket cannot be found or if the key represents a non-bucket value.
+func (tx *Tx) DeleteBucket(name []byte) error {
+	return tx.root.DeleteBucket(name)
+}
 
-	// Free all pages.
-	tx.forEachPage(b.root, 0, func(p *page, depth int) {
-		tx.db.freelist.free(tx.id(), p)
+// ForEach executes a function for each bucket in the root.
+// If the provided function returns an error then the iteration is stopped and
+// the error is returned to the caller.
+func (tx *Tx) ForEach(fn func(name []byte, b *Bucket) error) error {
+	return tx.root.ForEach(func(k, v []byte) error {
+		if err := fn(k, tx.root.Bucket(k)); err != nil {
+			return err
+		}
+		return nil
 	})
-
-	return nil
 }
 
 // OnCommit adds a handler function to be executed after the transaction successfully commits.
@@ -184,9 +124,8 @@ func (tx *Tx) OnCommit(fn func()) {
 // Commit writes all changes to disk and updates the meta page.
 // Returns an error if a disk write error occurs.
 func (tx *Tx) Commit() error {
-	if tx.managed {
-		panic("managed tx commit not allowed")
-	} else if tx.db == nil {
+	_assert(!tx.managed, "managed tx commit not allowed")
+	if tx.db == nil {
 		return ErrTxClosed
 	} else if !tx.writable {
 		return ErrTxNotWritable
@@ -196,33 +135,24 @@ func (tx *Tx) Commit() error {
 
 	// Rebalance nodes which have had deletions.
 	var startTime = time.Now()
-	tx.rebalance()
+	tx.root.rebalance()
 	tx.stats.RebalanceTime += time.Since(startTime)
 
 	// spill data onto dirty pages.
 	startTime = time.Now()
-	if err := tx.spill(); err != nil {
+	if err := tx.root.spill(); err != nil {
 		tx.close()
 		return err
 	}
 	tx.stats.SpillTime += time.Since(startTime)
 
-	// Spill buckets page.
-	p, err := tx.allocate((tx.buckets.size() / tx.db.pageSize) + 1)
-	if err != nil {
-		tx.close()
-		return err
-	}
-	tx.buckets.write(p)
-
-	// Free previous bucket page and update meta.
-	tx.db.freelist.free(tx.id(), tx.page(tx.meta.buckets))
-	tx.meta.buckets = p.id
+	// Free the old root bucket.
+	tx.meta.root.root = tx.root.root
 
 	// Free the freelist and allocate new pages for it. This will overestimate
 	// the size of the freelist but not underestimate the size (which would be bad).
-	tx.db.freelist.free(tx.id(), tx.page(tx.meta.freelist))
-	p, err = tx.allocate((tx.db.freelist.size() / tx.db.pageSize) + 1)
+	tx.db.freelist.free(tx.id(), tx.db.page(tx.meta.freelist))
+	p, err := tx.allocate((tx.db.freelist.size() / tx.db.pageSize) + 1)
 	if err != nil {
 		tx.close()
 		return err
@@ -257,9 +187,8 @@ func (tx *Tx) Commit() error {
 
 // Rollback closes the transaction and ignores all previous updates.
 func (tx *Tx) Rollback() error {
-	if tx.managed {
-		panic("managed tx rollback not allowed")
-	} else if tx.db == nil {
+	_assert(!tx.managed, "managed tx rollback not allowed")
+	if tx.db == nil {
 		return ErrTxClosed
 	}
 	tx.close()
@@ -268,13 +197,13 @@ func (tx *Tx) Rollback() error {
 
 func (tx *Tx) close() {
 	if tx.writable {
-		// Merge statistics.
-		tx.db.metalock.Lock()
-		tx.db.stats.TxStats.add(&tx.stats)
-		tx.db.metalock.Unlock()
-
 		// Remove writer lock.
 		tx.db.rwlock.Unlock()
+
+		// Merge statistics.
+		tx.db.statlock.Lock()
+		tx.db.stats.TxStats.add(&tx.stats)
+		tx.db.statlock.Unlock()
 	} else {
 		tx.db.removeTx(tx)
 	}
@@ -298,99 +227,6 @@ func (tx *Tx) allocate(count int) (*page, error) {
 	return p, nil
 }
 
-// rebalance attempts to balance all nodes.
-func (tx *Tx) rebalance() {
-	for _, n := range tx.nodes {
-		n.rebalance()
-	}
-}
-
-// spill writes all the nodes to dirty pages.
-func (tx *Tx) spill() error {
-	// Keep track of the current root nodes.
-	// We will update this at the end once all nodes are created.
-	type root struct {
-		node *node
-		pgid pgid
-	}
-	var roots []root
-
-	// Sort nodes by highest depth first.
-	nodes := make(nodesByDepth, 0, len(tx.nodes))
-	for _, n := range tx.nodes {
-		nodes = append(nodes, n)
-	}
-	sort.Sort(nodes)
-
-	// Spill nodes by deepest first.
-	for i := 0; i < len(nodes); i++ {
-		n := nodes[i]
-
-		// Save existing root buckets for later.
-		if n.parent == nil && n.pgid != 0 {
-			roots = append(roots, root{n, n.pgid})
-		}
-
-		// Split nodes into appropriate sized nodes.
-		// The first node in this list will be a reference to n to preserve ancestry.
-		newNodes := n.split(tx.db.pageSize)
-		tx.pending = newNodes
-
-		// If this is a root node that split then create a parent node.
-		if n.parent == nil && len(newNodes) > 1 {
-			n.parent = &node{tx: tx, isLeaf: false}
-			nodes = append(nodes, n.parent)
-		}
-
-		// Add node's page to the freelist.
-		if n.pgid > 0 {
-			tx.db.freelist.free(tx.id(), tx.page(n.pgid))
-		}
-
-		// Write nodes to dirty pages.
-		for i, newNode := range newNodes {
-			// Allocate contiguous space for the node.
-			p, err := tx.allocate((newNode.size() / tx.db.pageSize) + 1)
-			if err != nil {
-				return err
-			}
-
-			// Write the node to the page.
-			newNode.write(p)
-			newNode.pgid = p.id
-			newNode.parent = n.parent
-
-			// The first node should use the existing entry, other nodes are inserts.
-			var oldKey []byte
-			if i == 0 {
-				oldKey = n.key
-			} else {
-				oldKey = newNode.inodes[0].key
-			}
-
-			// Update the parent entry.
-			if newNode.parent != nil {
-				newNode.parent.put(oldKey, newNode.inodes[0].key, nil, newNode.pgid)
-			}
-
-			// Update the statistics.
-			tx.stats.Spill++
-		}
-
-		tx.pending = nil
-	}
-
-	// Update roots with new roots.
-	for _, root := range roots {
-		tx.buckets.updateRoot(root.pgid, root.node.root().pgid)
-	}
-
-	// Clear out nodes now that they are all spilled.
-	tx.nodes = make(map[pgid]*node)
-
-	return nil
-}
-
 // write writes any dirty pages to disk.
 func (tx *Tx) write() error {
 	// Sort pages by id.
@@ -443,43 +279,6 @@ func (tx *Tx) writeMeta() error {
 	return nil
 }
 
-// node creates a node from a page and associates it with a given parent.
-func (tx *Tx) node(pgid pgid, parent *node) *node {
-	// Retrieve node if it's already been created.
-	if tx.nodes == nil {
-		return nil
-	} else if n := tx.nodes[pgid]; n != nil {
-		return n
-	}
-
-	// Otherwise create a branch and cache it.
-	n := &node{tx: tx, parent: parent}
-	if n.parent != nil {
-		n.depth = n.parent.depth + 1
-	}
-	n.read(tx.page(pgid))
-	tx.nodes[pgid] = n
-
-	// Update statistics.
-	tx.stats.NodeCount++
-
-	return n
-}
-
-// dereference removes all references to the old mmap.
-func (tx *Tx) dereference() {
-	for _, n := range tx.nodes {
-		n.dereference()
-	}
-
-	for _, n := range tx.pending {
-		n.dereference()
-	}
-
-	// Update statistics
-	tx.stats.NodeDeref += len(tx.nodes) + len(tx.pending)
-}
-
 // page returns a reference to the page with a given id.
 // If page has been written to then a temporary bufferred page is returned.
 func (tx *Tx) page(id pgid) *page {
@@ -494,17 +293,6 @@ func (tx *Tx) page(id pgid) *page {
 	return tx.db.page(id)
 }
 
-// pageNode returns the in-memory node, if it exists.
-// Otherwise returns the underlying page.
-func (tx *Tx) pageNode(id pgid) (*page, *node) {
-	if tx.nodes != nil {
-		if n := tx.nodes[id]; n != nil {
-			return nil, n
-		}
-	}
-	return tx.page(id), nil
-}
-
 // forEachPage iterates over every page within a given page and executes a function.
 func (tx *Tx) forEachPage(pgid pgid, depth int, fn func(*page, int)) {
 	p := tx.page(pgid)
@@ -533,7 +321,7 @@ func (tx *Tx) Page(id int) (*PageInfo, error) {
 	}
 
 	// Build the page info.
-	p := tx.page(pgid(id))
+	p := tx.db.page(pgid(id))
 	info := &PageInfo{
 		ID:            id,
 		Count:         int(p.count),
diff --git a/tx_test.go b/tx_test.go
index 299cccc..036c0c5 100644
--- a/tx_test.go
+++ b/tx_test.go
@@ -5,27 +5,25 @@ import (
 	"fmt"
 	"math/rand"
 	"os"
-	"sort"
 	"strconv"
 	"strings"
 	"testing"
-	"testing/quick"
 
 	"github.com/stretchr/testify/assert"
 )
 
 // Ensure that committing a closed transaction returns an error.
-func TestTxCommitClosed(t *testing.T) {
+func TestTx_Commit_Closed(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		tx, _ := db.Begin(true)
-		tx.CreateBucket("foo")
+		tx.CreateBucket([]byte("foo"))
 		assert.NoError(t, tx.Commit())
 		assert.Equal(t, tx.Commit(), ErrTxClosed)
 	})
 }
 
 // Ensure that rolling back a closed transaction returns an error.
-func TestTxRollbackClosed(t *testing.T) {
+func TestTx_Rollback_Closed(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		tx, _ := db.Begin(true)
 		assert.NoError(t, tx.Rollback())
@@ -34,114 +32,69 @@ func TestTxRollbackClosed(t *testing.T) {
 }
 
 // Ensure that committing a read-only transaction returns an error.
-func TestTxCommitReadOnly(t *testing.T) {
+func TestTx_Commit_ReadOnly(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		tx, _ := db.Begin(false)
 		assert.Equal(t, tx.Commit(), ErrTxNotWritable)
 	})
 }
 
-// Ensure that the database can retrieve a list of buckets.
-func TestTxBuckets(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("foo")
-			tx.CreateBucket("bar")
-			tx.CreateBucket("baz")
-			buckets := tx.Buckets()
-			if assert.Equal(t, len(buckets), 3) {
-				assert.Equal(t, buckets[0].Name(), "bar")
-				assert.Equal(t, buckets[1].Name(), "baz")
-				assert.Equal(t, buckets[2].Name(), "foo")
-			}
-			return nil
-		})
-	})
-}
-
 // Ensure that creating a bucket with a read-only transaction returns an error.
-func TestTxCreateBucketReadOnly(t *testing.T) {
+func TestTx_CreateBucket_ReadOnly(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.View(func(tx *Tx) error {
-			assert.Equal(t, tx.CreateBucket("foo"), ErrTxNotWritable)
+			assert.Equal(t, tx.CreateBucket([]byte("foo")), ErrTxNotWritable)
 			return nil
 		})
 	})
 }
 
 // Ensure that creating a bucket on a closed transaction returns an error.
-func TestTxCreateBucketClosed(t *testing.T) {
+func TestTx_CreateBucket_Closed(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		tx, _ := db.Begin(true)
 		tx.Commit()
-		assert.Equal(t, tx.CreateBucket("foo"), ErrTxClosed)
+		assert.Equal(t, tx.CreateBucket([]byte("foo")), ErrTxClosed)
 	})
 }
 
 // Ensure that a Tx can retrieve a bucket.
-func TestTxBucket(t *testing.T) {
+func TestTx_Bucket(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			b := tx.Bucket("widgets")
-			if assert.NotNil(t, b) {
-				assert.Equal(t, "widgets", b.Name())
-			}
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			assert.NotNil(t, b)
 			return nil
 		})
 	})
 }
 
 // Ensure that a Tx retrieving a non-existent key returns nil.
-func TestTxGetMissing(t *testing.T) {
+func TestTx_Get_Missing(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
-			value := tx.Bucket("widgets").Get([]byte("no_such_key"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
+			value := tx.Bucket([]byte("widgets")).Get([]byte("no_such_key"))
 			assert.Nil(t, value)
 			return nil
 		})
 	})
 }
 
-// Ensure that retrieving all buckets returns writable buckets.
-func TestTxWritableBuckets(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.CreateBucket("woojits")
-			return nil
-		})
-		db.Update(func(tx *Tx) error {
-			buckets := tx.Buckets()
-			assert.Equal(t, len(buckets), 2)
-			assert.Equal(t, buckets[0].Name(), "widgets")
-			assert.Equal(t, buckets[1].Name(), "woojits")
-			buckets[0].Put([]byte("foo"), []byte("0000"))
-			buckets[1].Put([]byte("bar"), []byte("0001"))
-			return nil
-		})
-		db.View(func(tx *Tx) error {
-			assert.Equal(t, []byte("0000"), tx.Bucket("widgets").Get([]byte("foo")))
-			assert.Equal(t, []byte("0001"), tx.Bucket("woojits").Get([]byte("bar")))
-			return nil
-		})
-	})
-}
-
 // Ensure that a bucket can be created and retrieved.
-func TestTxCreateBucket(t *testing.T) {
+func TestTx_CreateBucket(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		// Create a bucket.
 		db.Update(func(tx *Tx) error {
-			assert.NoError(t, tx.CreateBucket("widgets"))
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
 			return nil
 		})
 
 		// Read the bucket through a separate transaction.
 		db.View(func(tx *Tx) error {
-			b := tx.Bucket("widgets")
+			b := tx.Bucket([]byte("widgets"))
 			assert.NotNil(t, b)
 			return nil
 		})
@@ -149,18 +102,19 @@ func TestTxCreateBucket(t *testing.T) {
 }
 
 // Ensure that a bucket can be created if it doesn't already exist.
-func TestTxCreateBucketIfNotExists(t *testing.T) {
+func TestTx_CreateBucketIfNotExists(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			assert.NoError(t, tx.CreateBucketIfNotExists("widgets"))
-			assert.NoError(t, tx.CreateBucketIfNotExists("widgets"))
-			assert.Equal(t, tx.CreateBucketIfNotExists(""), ErrBucketNameRequired)
+			assert.NoError(t, tx.CreateBucketIfNotExists([]byte("widgets")))
+			assert.NoError(t, tx.CreateBucketIfNotExists([]byte("widgets")))
+			assert.Equal(t, ErrBucketNameRequired, tx.CreateBucketIfNotExists([]byte{}))
+			assert.Equal(t, ErrBucketNameRequired, tx.CreateBucketIfNotExists(nil))
 			return nil
 		})
 
 		// Read the bucket through a separate transaction.
 		db.View(func(tx *Tx) error {
-			b := tx.Bucket("widgets")
+			b := tx.Bucket([]byte("widgets"))
 			assert.NotNil(t, b)
 			return nil
 		})
@@ -168,64 +122,53 @@ func TestTxCreateBucketIfNotExists(t *testing.T) {
 }
 
 // Ensure that a bucket cannot be created twice.
-func TestTxRecreateBucket(t *testing.T) {
+func TestTx_CreateBucket_Exists(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		// Create a bucket.
 		db.Update(func(tx *Tx) error {
-			assert.NoError(t, tx.CreateBucket("widgets"))
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
 			return nil
 		})
 
 		// Create the same bucket again.
 		db.Update(func(tx *Tx) error {
-			assert.Equal(t, ErrBucketExists, tx.CreateBucket("widgets"))
+			assert.Equal(t, ErrBucketExists, tx.CreateBucket([]byte("widgets")))
 			return nil
 		})
 	})
 }
 
 // Ensure that a bucket is created with a non-blank name.
-func TestTxCreateBucketWithoutName(t *testing.T) {
+func TestTx_CreateBucket_NameRequired(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			assert.Equal(t, ErrBucketNameRequired, tx.CreateBucket(""))
-			return nil
-		})
-	})
-}
-
-// Ensure that a bucket name is not too long.
-func TestTxCreateBucketWithLongName(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			assert.NoError(t, tx.CreateBucket(strings.Repeat("X", 255)))
-			assert.Equal(t, ErrBucketNameTooLarge, tx.CreateBucket(strings.Repeat("X", 256)))
+			assert.Equal(t, ErrBucketNameRequired, tx.CreateBucket(nil))
 			return nil
 		})
 	})
 }
 
 // Ensure that a bucket can be deleted.
-func TestTxDeleteBucket(t *testing.T) {
+func TestTx_DeleteBucket(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		// Create a bucket and add a value.
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("foo"), []byte("bar"))
+			tx.CreateBucket([]byte("widgets"))
+			tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
 			return nil
 		})
 
 		// Save root page id.
 		var root pgid
 		db.View(func(tx *Tx) error {
-			root = tx.Bucket("widgets").root
+			root = tx.Bucket([]byte("widgets")).root
 			return nil
 		})
 
 		// Delete the bucket and make sure we can't get the value.
 		db.Update(func(tx *Tx) error {
-			assert.NoError(t, tx.DeleteBucket("widgets"))
-			assert.Nil(t, tx.Bucket("widgets"))
+			assert.NoError(t, tx.DeleteBucket([]byte("widgets")))
+			assert.Nil(t, tx.Bucket([]byte("widgets")))
 			return nil
 		})
 
@@ -234,257 +177,42 @@ func TestTxDeleteBucket(t *testing.T) {
 			assert.Equal(t, []pgid{7, 6, root, 2}, db.freelist.all())
 
 			// Create the bucket again and make sure there's not a phantom value.
-			assert.NoError(t, tx.CreateBucket("widgets"))
-			assert.Nil(t, tx.Bucket("widgets").Get([]byte("foo")))
+			assert.NoError(t, tx.CreateBucket([]byte("widgets")))
+			assert.Nil(t, tx.Bucket([]byte("widgets")).Get([]byte("foo")))
 			return nil
 		})
 	})
 }
 
 // Ensure that deleting a bucket on a closed transaction returns an error.
-func TestTxDeleteBucketClosed(t *testing.T) {
+func TestTx_DeleteBucket_Closed(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		tx, _ := db.Begin(true)
 		tx.Commit()
-		assert.Equal(t, tx.DeleteBucket("foo"), ErrTxClosed)
+		assert.Equal(t, tx.DeleteBucket([]byte("foo")), ErrTxClosed)
 	})
 }
 
 // Ensure that deleting a bucket with a read-only transaction returns an error.
-func TestTxDeleteBucketReadOnly(t *testing.T) {
+func TestTx_DeleteBucket_ReadOnly(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.View(func(tx *Tx) error {
-			assert.Equal(t, tx.DeleteBucket("foo"), ErrTxNotWritable)
-			return nil
-		})
-	})
-}
-
-// Ensure that an error is returned when deleting from a bucket that doesn't exist.
-func TestTxDeleteBucketNotFound(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			assert.Equal(t, ErrBucketNotFound, tx.DeleteBucket("widgets"))
+			assert.Equal(t, tx.DeleteBucket([]byte("foo")), ErrTxNotWritable)
 			return nil
 		})
 	})
 }
 
-// Ensure that a Tx cursor can iterate over an empty bucket without error.
-func TestTxCursorEmptyBucket(t *testing.T) {
+// Ensure that nothing happens when deleting a bucket that doesn't exist.
+func TestTx_DeleteBucket_NotFound(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			return tx.CreateBucket("widgets")
-		})
-		db.View(func(tx *Tx) error {
-			c := tx.Bucket("widgets").Cursor()
-			k, v := c.First()
-			assert.Nil(t, k)
-			assert.Nil(t, v)
+			assert.Equal(t, ErrBucketNotFound, tx.DeleteBucket([]byte("widgets")))
 			return nil
 		})
 	})
 }
 
-// Ensure that a Tx cursor can reverse iterate over an empty bucket without error.
-func TestCursorEmptyBucketReverse(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			return tx.CreateBucket("widgets")
-		})
-		db.View(func(tx *Tx) error {
-			c := tx.Bucket("widgets").Cursor()
-			k, v := c.Last()
-			assert.Nil(t, k)
-			assert.Nil(t, v)
-			return nil
-		})
-	})
-}
-
-// Ensure that a Tx cursor can iterate over a single root with a couple elements.
-func TestTxCursorLeafRoot(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("baz"), []byte{})
-			tx.Bucket("widgets").Put([]byte("foo"), []byte{0})
-			tx.Bucket("widgets").Put([]byte("bar"), []byte{1})
-			return nil
-		})
-		tx, _ := db.Begin(false)
-		c := tx.Bucket("widgets").Cursor()
-
-		k, v := c.First()
-		assert.Equal(t, string(k), "bar")
-		assert.Equal(t, v, []byte{1})
-
-		k, v = c.Next()
-		assert.Equal(t, string(k), "baz")
-		assert.Equal(t, v, []byte{})
-
-		k, v = c.Next()
-		assert.Equal(t, string(k), "foo")
-		assert.Equal(t, v, []byte{0})
-
-		k, v = c.Next()
-		assert.Nil(t, k)
-		assert.Nil(t, v)
-
-		k, v = c.Next()
-		assert.Nil(t, k)
-		assert.Nil(t, v)
-
-		tx.Rollback()
-	})
-}
-
-// Ensure that a Tx cursor can iterate in reverse over a single root with a couple elements.
-func TestTxCursorLeafRootReverse(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("baz"), []byte{})
-			tx.Bucket("widgets").Put([]byte("foo"), []byte{0})
-			tx.Bucket("widgets").Put([]byte("bar"), []byte{1})
-			return nil
-		})
-		tx, _ := db.Begin(false)
-		c := tx.Bucket("widgets").Cursor()
-
-		k, v := c.Last()
-		assert.Equal(t, string(k), "foo")
-		assert.Equal(t, v, []byte{0})
-
-		k, v = c.Prev()
-		assert.Equal(t, string(k), "baz")
-		assert.Equal(t, v, []byte{})
-
-		k, v = c.Prev()
-		assert.Equal(t, string(k), "bar")
-		assert.Equal(t, v, []byte{1})
-
-		k, v = c.Prev()
-		assert.Nil(t, k)
-		assert.Nil(t, v)
-
-		k, v = c.Prev()
-		assert.Nil(t, k)
-		assert.Nil(t, v)
-
-		tx.Rollback()
-	})
-}
-
-// Ensure that a Tx cursor can restart from the beginning.
-func TestTxCursorRestart(t *testing.T) {
-	withOpenDB(func(db *DB, path string) {
-		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			tx.Bucket("widgets").Put([]byte("bar"), []byte{})
-			tx.Bucket("widgets").Put([]byte("foo"), []byte{})
-			return nil
-		})
-
-		tx, _ := db.Begin(false)
-		c := tx.Bucket("widgets").Cursor()
-
-		k, _ := c.First()
-		assert.Equal(t, string(k), "bar")
-
-		k, _ = c.Next()
-		assert.Equal(t, string(k), "foo")
-
-		k, _ = c.First()
-		assert.Equal(t, string(k), "bar")
-
-		k, _ = c.Next()
-		assert.Equal(t, string(k), "foo")
-
-		tx.Rollback()
-	})
-}
-
-// Ensure that a Tx can iterate over all elements in a bucket.
-func TestTxCursorIterate(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test in short mode.")
-	}
-
-	f := func(items testdata) bool {
-		withOpenDB(func(db *DB, path string) {
-			// Bulk insert all values.
-			tx, _ := db.Begin(true)
-			tx.CreateBucket("widgets")
-			b := tx.Bucket("widgets")
-			for _, item := range items {
-				assert.NoError(t, b.Put(item.Key, item.Value))
-			}
-			assert.NoError(t, tx.Commit())
-
-			// Sort test data.
-			sort.Sort(items)
-
-			// Iterate over all items and check consistency.
-			var index = 0
-			tx, _ = db.Begin(false)
-			c := tx.Bucket("widgets").Cursor()
-			for k, v := c.First(); k != nil && index < len(items); k, v = c.Next() {
-				assert.Equal(t, k, items[index].Key)
-				assert.Equal(t, v, items[index].Value)
-				index++
-			}
-			assert.Equal(t, len(items), index)
-			tx.Rollback()
-		})
-		return true
-	}
-	if err := quick.Check(f, qconfig()); err != nil {
-		t.Error(err)
-	}
-	fmt.Fprint(os.Stderr, "\n")
-}
-
-// Ensure that a transaction can iterate over all elements in a bucket in reverse.
-func TestTxCursorIterateReverse(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test in short mode.")
-	}
-
-	f := func(items testdata) bool {
-		withOpenDB(func(db *DB, path string) {
-			// Bulk insert all values.
-			tx, _ := db.Begin(true)
-			tx.CreateBucket("widgets")
-			b := tx.Bucket("widgets")
-			for _, item := range items {
-				assert.NoError(t, b.Put(item.Key, item.Value))
-			}
-			assert.NoError(t, tx.Commit())
-
-			// Sort test data.
-			sort.Sort(revtestdata(items))
-
-			// Iterate over all items and check consistency.
-			var index = 0
-			tx, _ = db.Begin(false)
-			c := tx.Bucket("widgets").Cursor()
-			for k, v := c.Last(); k != nil && index < len(items); k, v = c.Prev() {
-				assert.Equal(t, k, items[index].Key)
-				assert.Equal(t, v, items[index].Value)
-				index++
-			}
-			assert.Equal(t, len(items), index)
-			tx.Rollback()
-		})
-		return true
-	}
-	if err := quick.Check(f, qconfig()); err != nil {
-		t.Error(err)
-	}
-	fmt.Fprint(os.Stderr, "\n")
-}
-
 // Ensure that Tx commit handlers are called after a transaction successfully commits.
 func TestTx_OnCommit(t *testing.T) {
 	var x int
@@ -492,7 +220,7 @@ func TestTx_OnCommit(t *testing.T) {
 		db.Update(func(tx *Tx) error {
 			tx.OnCommit(func() { x += 1 })
 			tx.OnCommit(func() { x += 2 })
-			return tx.CreateBucket("widgets")
+			return tx.CreateBucket([]byte("widgets"))
 		})
 	})
 	assert.Equal(t, 3, x)
@@ -505,7 +233,7 @@ func TestTx_OnCommit_Rollback(t *testing.T) {
 		db.Update(func(tx *Tx) error {
 			tx.OnCommit(func() { x += 1 })
 			tx.OnCommit(func() { x += 2 })
-			tx.CreateBucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
 			return errors.New("rollback this commit")
 		})
 	})
@@ -526,8 +254,8 @@ func benchmarkTxCursor(b *testing.B, total int) {
 	withOpenDB(func(db *DB, path string) {
 		// Write data to bucket.
 		db.Update(func(tx *Tx) error {
-			tx.CreateBucket("widgets")
-			bucket := tx.Bucket("widgets")
+			tx.CreateBucket([]byte("widgets"))
+			bucket := tx.Bucket([]byte("widgets"))
 			for i := 0; i < total; i++ {
 				bucket.Put([]byte(fmt.Sprintf("%016d", indexes[i])), value)
 			}
@@ -539,7 +267,7 @@ func benchmarkTxCursor(b *testing.B, total int) {
 		for i := 0; i < b.N; i++ {
 			db.View(func(tx *Tx) error {
 				count := 0
-				c := tx.Bucket("widgets").Cursor()
+				c := tx.Bucket([]byte("widgets")).Cursor()
 				for k, _ := c.First(); k != nil; k, _ = c.Next() {
 					count++
 				}
@@ -564,7 +292,7 @@ func benchmarkTxPutRandom(b *testing.B, total int) {
 	value := []byte(strings.Repeat("0", 64))
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			return tx.CreateBucket("widgets")
+			return tx.CreateBucket([]byte("widgets"))
 		})
 		var tx *Tx
 		var bucket *Bucket
@@ -575,7 +303,7 @@ func benchmarkTxPutRandom(b *testing.B, total int) {
 						tx.Commit()
 					}
 					tx, _ = db.Begin(true)
-					bucket = tx.Bucket("widgets")
+					bucket = tx.Bucket([]byte("widgets"))
 				}
 				bucket.Put([]byte(strconv.Itoa(indexes[i])), value)
 			}
@@ -595,10 +323,10 @@ func benchmarkTxPutSequential(b *testing.B, total int) {
 	value := []byte(strings.Repeat("0", 64))
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
-			return tx.CreateBucket("widgets")
+			return tx.CreateBucket([]byte("widgets"))
 		})
 		db.Update(func(tx *Tx) error {
-			bucket := tx.Bucket("widgets")
+			bucket := tx.Bucket([]byte("widgets"))
 			for j := 0; j < b.N; j++ {
 				for i := 0; i < total; i++ {
 					bucket.Put([]byte(strconv.Itoa(i)), value)
@@ -608,3 +336,36 @@ func benchmarkTxPutSequential(b *testing.B, total int) {
 		})
 	})
 }
+
+func ExampleTx_Rollback() {
+	// Open the database.
+	db, _ := Open(tempfile(), 0666)
+	defer os.Remove(db.Path())
+	defer db.Close()
+
+	// Create a bucket.
+	db.Update(func(tx *Tx) error {
+		return tx.CreateBucket([]byte("widgets"))
+	})
+
+	// Set a value for a key.
+	db.Update(func(tx *Tx) error {
+		return tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar"))
+	})
+
+	// Update the key but rollback the transaction so it never saves.
+	tx, _ := db.Begin(true)
+	b := tx.Bucket([]byte("widgets"))
+	b.Put([]byte("foo"), []byte("baz"))
+	tx.Rollback()
+
+	// Ensure that our original value is still set.
+	db.View(func(tx *Tx) error {
+		value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
+		fmt.Printf("The value for 'foo' is still: %s\n", string(value))
+		return nil
+	})
+
+	// Output:
+	// The value for 'foo' is still: bar
+}