fsynch of pg_log write..

After the discussion about implementing a flag that
would selectively disable fsynch on the pg_log file,
I visited xact.c and tried a little test.

The code in RecordTransactionCommit looks essentially like
(ignoring stuff related to leaks)

FlushBufferPool /* flush and fsync the data blocks */
TransactionIdCommit /* log the fact that the transaction's done */
FlushBufferPool /* flush and fsync pg_log and whatever else
has changed during this brief period of time */

I just added a couple of lines of code that saves
disableFsync and sets it true before the second call
to FlushBufferPool, restoring it to its original state
afterwards.

Running without "-F", my disk is blessedly silent when
I access my web pages that hit the database several times
with read-only selects used to customize the presentation
to the user.

Cool!

So...does it sound like I'm doing the right thing?

- Don Baccus, Portland OR <dhogaza(at)pacifier(dot)com>
Nature photos, on-line guides, and other goodies at
http://donb.photo.net