Royce Ausburn <royce...@inomial.com> writes:
> I have a problem with autovacuum apparently not doing the job I need it to do.
Hm, I wonder whether you're getting bit by bug #5759, which was fixed
after 8.3.12.
> I have a table named datasession that is frequently inserted, updated and
> deleted from. Typically the table will have a few thousand rows in it. Each
> row typically survives a few days and is updated every 5 - 10 mins. The
> application receives unreliable, potentially duplicate data from its source,
> so this table is heavily used for synchronising application threads as well.
> A typical access pattern is:
> - tx begin
> - SELECT FOR UPDATE on a single row
> - Do some application processing (1 - 100 ms)
> - Possibly UPDATE the row
> - tx commit
Transactions of that form would not interfere with autovacuum. You'd
need something that wants exclusive lock, like a schema change.
> I've read some recent threads and found a discussion (below) on auto vacuum
> that mentions auto vacuum will be cancelled when a client requests a lock
> that auto vacuum is usingÂ… My questions:
> 1) Does it look like I'm affected by the same problem as in the below
> discussion?
Not unless you're seeing a lot of "canceling autovacuum task" messages
in the postmaster log.
regards, tom lane
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