Re: blocking automatic vacuum

Uwe Bartels  writes:
> i'm pretty sure there is no repetitive ddl happen on this or any other
> table. i checked this with the developers.

Well, *something* was blocking that RowExclusiveLock request, and for
sure it wasn't autovacuum.  There has to be something else going on.

> but if i had an anti-wraparound vacuum, then i should see warnings like
> these in the log. am i right? I don't have any warnings that day.

> WARNING:  database "mydb" must be vacuumed within 177009986 transactions
> HINT:  To avoid a database shutdown, execute a database-wide VACUUM in "mydb".

Uh, no.  Anti-wraparound vacuums are performed long before you would get
to the point of seeing any actual warnings.

			regards, tom lane