Hi, On 2022-09-06 14:15:56 +0100, Dave Page wrote: > Vik and I looked at this a little, and found that we actually don't have > generally have GetCurrentTransactionStopTimestamp() at this point - a > simple 'select * from pg_class' will result in 9 passes of this code, none > of which have xactStopTimestamp != 0.
Huh, pgstat_report_stat() used GetCurrentTransactionStopTimestamp() has used for a long time. Wonder when that was broken. Looks like it's set only when a xid is assigned. We should fix this. > After discussing it a little, we came to the conclusion that for the stated > use case, xactStartTimestamp is actually accurate enough, provided that we > only ever update it with a newer value. It would only likely be in extreme > edge-cases where the difference between start and end transaction time > would have any bearing on whether or not one might drop a table/index for > lack of use. I don't at all agree with this. Since we already use GetCurrentTransactionStopTimestamp() in this path we should fix it. Greetings, Andres Freund
