On Tue, Nov 28, 2017 at 1:36 PM, Feike Steenbergen <feikesteenber...@gmail.com> wrote: > On a server with a very frequent xid wraparound I can see that the > anti-wraparound vacuum is finished very quickly with the heap, yet it still > scans all the indexes, which causes it to still have to read a lot of data, > which takes a considerable amount of time.
BTW, a good short term solution for you might be to change the vacuum cost delay settings. They're pretty conservative by default. There is a good chance that your indexes are mostly in memory even on large tables, and B-Tree indexes are read sequentially during VACUUM. Often, autovacuum runs at a much slower rate than is actually possible, which isn't necessarily the right trade-off. -- Peter Geoghegan
