From: Bruce Momjian <pgman@candle.pha.pa.us>
Message-Id: <200408071739.i77HdKk00742@candle.pha.pa.us>
Subject: Re: Vacuum Cost Documentation?
In-Reply-To: <4114DC23.6090108@Yahoo.com>
To: Jan Wieck <JanWieck@Yahoo.com>
Date: Sat, 7 Aug 2004 13:39:20 -0400 (EDT)
Cc: "Matthew T. O'Connor" <matthew@zeut.net>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
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Jan Wieck wrote:
> On 8/6/2004 11:34 PM, Bruce Momjian wrote:
> 
> > Jan Wieck wrote:
> >> On 8/6/2004 9:04 PM, Bruce Momjian wrote:
> >> 
> >> > Updated.  Thanks.
> >> 
> >> I thought we want to have the feature activated ... I reversed your 
> >> change and brought guc.c in sync instead.
> > 
> > Uh, if the guy is doing a vacuum at night, does he want the delay? 
> > Seems someone should have to enable the delay by default, or does your
> > setup recoginize when it is being run on a lightly loaded system?
> > 
> > 
> 
> Those people will instantly realize what is going on and either change 
> the delay setting or start running vacuum at daytime too.
> 
> What this buys us is that over time we will see less researches and 
> articles telling people that you have to bring down a PostgreSQL DB 
> frequently for vacuum maintenance because those "testers" run their fair 
> comparisions with out of the box configuration settings.

I am not in favor of adding a delay in VACUUM unless people ask for it. 
Imagine either night vacuum or a vacuum you run in your application
after you delete and just before you load a table.  Neither want a
vacuum.  I think people who want a delay will think to ask for it while
people who want a quick vacuum will just think that vacuum is slow.

-- 
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