Document that wal_sync_method open_* methods use O_DIRECT, if available.

Backpatch to 8.2.X.

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 9608f199fe0104c471951a6d29248c214218ee58..f8fa9c3c23c72dffdb963c0a8a14cf56d64daf10 100644 (file)
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1385,6 +1385,7 @@ SET ENABLE_SEQSCAN TO OFF;
         Not all of these choices are available on all platforms.
         The default is the first method in the above list that is supported
         by the platform.
+        The <literal>open_</>* options also use <literal>O_DIRECT</> if available.
         This parameter can only be set in the <filename>postgresql.conf</>
         file or on the server command line.
        </para>