Update journaling performance docs based on comments by Michael Renner.

diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml
index 3b013746a313306c2f0b3f8ba711fd47e7f3c35f..e69463a9e22ce5ccbcc2063f615879f9d2eac3fd 100644 (file)
--- a/doc/src/sgml/wal.sgml
+++ b/doc/src/sgml/wal.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Reliability and the Write-Ahead Log
@@ -139,13 +139,13 @@
     
      Because WAL restores database file
      contents after a crash, it is not necessary to use a
-     journaled filesystem;  in fact, journaling overhead can
-     reduce performance.  For best performance, turn off
-     data journaling as a filesystem mount
-     option, e.g. use data=writeback on Linux.
-     Meta-data journaling (e.g.  file creation and directory
-     modification) is still desirable for faster rebooting after
-     a crash.
+     journaled filesystem for reliability.  In fact, journaling
+     overhead can reduce performance, especially if journaling
+     causes file system data to be flushed
+     to disk.  Fortunately, data flushing during journaling can
+     often be disabled with a filesystem mount option, e.g.
+     data=writeback on a Linux ext3 file system.
+     Journaled file systems do improve boot speed after a crash.