On Sat, Jul 7, 2012 at 3:52 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Jul 7, 2012, at 9:07 AM, Euler Taveira <eu...@timbira.com> wrote: >> On 07-07-2012 09:00, Satoshi Nagayasu wrote: >>> I've created new patch to get/reset statistics of WAL buffer >>> writes (flushes) caused by WAL buffer full. >>> >> This new statistic doesn't solve your problem (tune wal_buffers). It doesn't >> give you the wal_buffers value. It only says "hey, I needed more buffers so I >> write those dirty ones". It doesn't say how many. I would like to have >> something that says "hey, you have 1000 buffers available and you are using >> 100 buffers (10%)". This new statistic is only useful for decreasing the >> WALWriteLock contention. > > The number of WAL buffers that you are using is going to change so quickly as > to be utterly meaningless. I don't really see that there's any statistic we > could gather that would tell us how many WAL buffers are needed. This patch > seems like it's on the right track, at least telling you how often you're > running out.
We could keep a high watermark of "what's the largest percentage we've used", perhaps? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
