Message-ID: <48B1AB17.9010905@zeut.net>
Date: Sun, 24 Aug 2008 14:40:23 -0400
From: "Matthew T. O'Connor" <matthew@zeut.net>
User-Agent: Thunderbird 2.0.0.16 (Windows/20080708)
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To: "Joshua D. Drake" <jd@commandprompt.com>
CC: Merlin Moncure <mmoncure@gmail.com>, Bruce Momjian <bruce@momjian.us>,
	Pavan Deolasee <pavan.deolasee@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>,
	Pgsql Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [PATCHES] VACUUM Improvements - WIP Patch
References: <2e78013d0807132050j16cdc558s4dc3f889371a937d@mail.gmail.com>	
	<200808230336.m7N3aOc15945@momjian.us>
	<b42b73150808240630r59ad34f3l24a980280cdc52d9@mail.gmail.com>
	<48B1831F.7010002@commandprompt.com>
In-Reply-To: <48B1831F.7010002@commandprompt.com>
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Joshua D. Drake wrote:
> Merlin Moncure wrote:
>> Well, there doesn't seem to be a TODO for partial/restartable vacuums,
>> which were mentioned upthread.  This is a really desirable feature for
>> big databases and removes one of the reasons to partition large
>> tables.
> I would agree that partial vacuums would be very useful. 


I think everyone agrees that partial vacuums would be useful / *A Good 
Thing* but it's the implementation that is the issue.  I was thinking 
about Alvaro's recent work to make vacuum deal with TOAST tables 
separately, which is almost like a partial vacuum since it effectively 
splits the vacuum work up into multiple independent blocks of work, the 
limitation obviously being that it can only split the work around 
TOAST.  Is there anyway that vacuum could work per relfile since we 
already split tables into files that are never greater than 1G?  I would 
think that if Vacuum never had more than 1G of work to do at any given 
moment it would make it much more manageable.