Avoid trashing page cache on Tx.Copy().

This commit change the database copy to use O_DIRECT so that the Linux page
cache is not trashed during a backup. This is only available on Linux.

1 files changed, 1 insertions, 1 deletions

diff --git a/tx.go b/tx.go
index 823b06d..8791adf 100644
--- a/tx.go
+++ b/tx.go
@@ -240,7 +240,7 @@ func (tx *Tx) close() {
 // Copy will write exactly tx.Size() bytes into the writer.
 func (tx *Tx) Copy(w io.Writer) error {
 	// Open reader on the database.
-	f, err := os.Open(tx.db.path)
+	f, err := os.OpenFile(tx.db.path, os.O_RDONLY|odirect, 0)
 	if err != nil {
 		_ = tx.Rollback()
 		return err