Re: [HACKERS] Re: [QUESTIONS] MySQL benchmark page
Marc G. Fournier <scrappy@hub.org>
From: The Hermit Hacker <scrappy@hub.org>
To: Bruce Momjian <maillist@candle.pha.pa.us>
Cc: herouth@oumail.openu.ac.il, pgsql-hackers@postgresql.org
Date: 1998-02-03T18:46:22Z
Lists: pgsql-hackers
On Tue, 3 Feb 1998, Bruce Momjian wrote: > > On Tue, 3 Feb 1998, Herouth Maoz wrote: > > > > > At 15:01 +0200 on 2/2/98, The Hermit Hacker wrote: > > > > > > I think the garbage collection should be separated from the statistics. > > > Garbage collection needs a write lock, statistics only a read lock. If they > > > are not done at the same time, the various tables would be locked for > > > shorter periods. > > > > Hrmmmm...good point, I think. Bruce? Vadim? When vacuum'ng a > > large table, how much time is spend 'garbage collecting' vs 'statistics'? > > I thought that 'vacuum analyze' *was* the statistics aspect of it? Where > > just 'vacuum' was only garbage collection...? > > This is correct. Vacuum is fast, vacuum analyze is pretty slow. We > could separate them, I guess, and that would eliminate the write-lock > and be only a readlock. Possible to slip it in for v6.3? Would make it so that an analyze could be done nightly, to keep statistics up, and then a vacuum once a week or so just for garbage collection...?