On Jun 21, 2007, at 3:37 PM, Steven Flatt wrote:
Thanks everyone. It appears that we had hacked the 502.pgsql script for our 8.1 build to disable the daily vacuum. I was not aware of this when building and upgrading to 8.2.

Much better to change stuff in a config file than to hack installed scripts, for this very reason. :)

So it looks like for the past two weeks, that 36 hour db-wide vacuum has been running every 24 hours. Good for it for being reasonably non-intrusive and going unnoticed until now. :)

Although apparently not related anymore, I still think it was a good move to change autovacuum_freeze_max_age from 200 million to 2 billion.

If you set that to 2B, that means you're 2^31-"2 billion"-1000000 transactions away from a shutdown when autovac finally gets around to trying to run a wraparound vacuum on a table. If you have any number of large tables, that could be a big problem, as autovac could get tied up on a large table for a long enough period that the table needing to be frozen doesn't get frozen in time.

I suspect 1B is a much better setting. I probably wouldn't go past 1.5B.
--
Jim Nasby                                            [EMAIL PROTECTED]
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)



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