Re: How to make lazy VACUUM of one table run in several transactions ?

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Hannu Krosing <hannu@tm.ee>
Cc: Alvaro Herrera <alvherre@dcc.uchile.cl>, pgsql-hackers@postgresql.org
Date: 2005-04-26T21:54:44Z
Lists: pgsql-hackers
Hannu Krosing <hannu@tm.ee> writes:
> Could I avoid having a transaction at all?

Not really; too much of the database access infrastructure is tied to
transaction stuff ... even facilities as basic as memory management.

> As VACUUM is not "transactional" in the sense that it does not change
> anything visible to users ever, can't be undone by rollback, etc... ,
> could it be possible to create enough "transaction-like" environment for
> it to really run outside of transactions. Perhaps just advancing
> oldestXmin at certain intervals ?

I wonder whether you could avoid advertising the VACUUM's XID in PGPROC.
Not sure that this can work, but it would be a lot simpler than stopping
and starting transactions ...

			regards, tom lane