Greg Smith <greg@xxxxxxxxxxxxxxx> writes: > If anything, I'd expect people to want to increase how often it runs, > for tables where much less than 20% dead is a problem. The most common > situation I've seen where that's the case is when you have a hotspot of > heavily updated rows in a large table, and this may match some of the > situations that Robert was alluding to seeing. Let's say you have a big > table where 0.5% of the users each update their respective records > heavily, averaging 30 times each. That's only going to result in 15% > dead rows, so no autovacuum. But latency for those users will suffer > greatly, because they might have to do lots of seeking around to get > their little slice of the data. With a little luck, HOT will alleviate that case, since HOT updates can be reclaimed without running vacuum per se. I agree there's a risk there though. Now that partial vacuum is available, it'd be a real good thing to revisit these numbers. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
