Skip site navigation (1) Skip section navigation (2)

Re: [HACKERS] Re: [PORTS] vacuum takes too long

From: The Hermit Hacker <scrappy(at)hub(dot)org>
To: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
Cc: "Jackson, DeJuan" <djackson(at)cpsgroup(dot)com>, dave(at)turbocat(dot)de, ports(at)postgreSQL(dot)org, hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] Re: [PORTS] vacuum takes too long
Date: 1999-01-08 06:17:03
Message-ID: Pine.BSF.4.05.9901080215430.417-100000@thelab.hub.org (view raw or flat)
Thread:
Lists: pgsql-hackerspgsql-ports
On Thu, 7 Jan 1999, Bruce Momjian wrote:

> > With MVCC an occasional 'vacuum analyze' should only be noticed from the
> > performance improvements.  As far as I can tell most of the work done by
> > an analyze is in reading the table data.  If you make sure to write the
> > new information at the end of the transaction you only lock the indexes
> > for the amount of time it takes to write them.
> > 
> > I see a 'vacuum analyze' being less of a problem than 'vacuum'.
> > Any of you experts can contradict my assumptions.
> 
> The problem is that vacuum analyze does both vacuum and analyze. 
> Analyze takes so long, we figured we might as well vacuum too.  Maybe we
> need to change that.

There is, IMHO, no problem with them being combined...in the past, the
problem was that the whole system was effectively locked up while a vacuum
analyze was being run because one of the 'statistics' tables was being
locked during the whole thing, instead of when required...

As DeJuan points out, though, this should no longer be a problem with
MVCC...

Marc G. Fournier                                
Systems Administrator @ hub.org 
primary: scrappy(at)hub(dot)org           secondary: scrappy(at){freebsd|postgresql}.org 


In response to

pgsql-ports by date

Next:From: Unprivileged userDate: 1999-01-08 08:23:48
Subject: Port Bug Report: EOL prob with documentation .tar.gz files
Previous:From: Unprivileged userDate: 1999-01-07 21:03:52
Subject: Port Bug Report:

pgsql-hackers by date

Next:From: Jose' SoaresDate: 1999-01-08 12:37:57
Subject: Re: [GENERAL] select using date
Previous:From: Thomas G. LockhartDate: 1999-01-08 05:32:01
Subject: Re: [HACKERS] Outer Joins (and need CASE help)

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group