Re: [HACKERS] Re: [QUESTIONS] MySQL benchmark page

Bruce Momjian <maillist@candle.pha.pa.us>

From: Bruce Momjian <maillist@candle.pha.pa.us>
To: scrappy@hub.org (The Hermit Hacker)
Cc: herouth@oumail.openu.ac.il, pgsql-hackers@postgresql.org
Date: 1998-02-03T18:22:22Z
Lists: pgsql-hackers
> 
> 
> 
> Nobody likes to take the time to move discussions, do they?  And ya, I'm
> about as guilty *sigh*
> 
> Move to pgsql-hackers@postgresql.org...
> 
> 
> 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.

-- 
Bruce Momjian
maillist@candle.pha.pa.us