By default, the
SAS Web Infrastructure Platform Data Server confirms each transaction is written to the WAL before a commit is complete.
When you have a high volume of insert, update, or delete statements, consider moving
the WAL to a separate disk resource, especially a solid-state drive (SSD) or other
fast storage device.
To move the WAL directory
to a separate drive or device, use symbolic links to point to the
new location. The following example shows the commands to execute
on a UNIX system:
pg_ctl stop $PGDATA
mkdir -p /mountpoint2/.../pg_xlog
mv /mountpoint1/.../pg_xlog/* /mountpoint2/.../pg_xlog/
rmdir /mountpoint1/.../pg_xlog
ln -s /mountpoint2/.../pg_xlog/ /mountpoint1/.../pg_xlog
pg_ctl start $PGDATA
where mountpoint1 is
the link name and mountpoint2 is
the new physical directory.
The following example
shows the commands to execute on a Windows system:
pg_ctl stop $PGDATA
mkdir -p /mountpoint2/.../pg_xlog
mv /mountpoint1/.../pg_xlog/* /mountpoint2/.../pg_xlog/
rmdir /mountpoint1/.../pg_xlog
mklink /J C:\PostgreSQL\8.3\data\pg_xlog Z:\pg_xlog
pg_ctl start $PGDATA