Re: PATCH to allow concurrent VACUUMs to not lock each

Hannu Krosing <hannu(at)skype(dot)net> writes:
> hel kenal peval, P, 2006-07-30 kell 14:11, kirjutas Alvaro Herrera:
>> What was idea behind moving vac_update_relstats to a separate
>> transaction? I'm wondering if it's still needed, if it further enhances
>> the system somehow, or your patch did something differently than what
>> was applied.

> The part of transactions which actually modified the data (iirc it updates
> relpages and reltuples in pg_class) is not safe to ignore by concurrent
> vacuum, say a vacuum on pg_class .

But that's done as a nontransactional update, or at least was the last
time I looked, so there's no need to do it in a separate xact.

Knew I should have taken time to review that patch before it went in ...

regards, tom lane