Thread: WAL FILES

WAL FILES

From
"Gershon M. Wolfe"
Date:
I am getting the following DEBUG message
XLogWrite: new log file created - consider increasing WAL_FILES

What would be a good number of files to shoot for, I am currently
using the default.  Some of my table are into the Gigabyte level.

Thanks.
Gary


Re: WAL FILES

From
Peter Eisentraut
Date:
Gershon M. Wolfe writes:

> I am getting the following DEBUG message
>
>     XLogWrite: new log file created - consider increasing WAL_FILES
>
> What would be a good number of files to shoot for, I am currently
> using the default.  Some of my table are into the Gigabyte level.

This depends on the amount of data modification you do per transaction.

If the transaction that caused this message is a typical work load (and
not just a one-time bulk load, for instance) you can try to raise
WAL_FILES until the message goes away.  I don't have a good formula at
hand, but basically WAL logs everything that you change during a
transaction.

You could perform a typical (long) transaction, hold off on the commit and
check the size of the accumulated logs under $PGDATA/pg_xlog.

-- 
Peter Eisentraut   peter_e@gmx.net