Re: Automatic free space map filling

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От Jim C. Nasby
Тема Re: Automatic free space map filling
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Msg-id 20060304022648.GB82012@pervasive.com
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Ответ на Re: Automatic free space map filling  (Tom Lane <tgl@sss.pgh.pa.us>)
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On Fri, Mar 03, 2006 at 11:37:00AM -0500, Tom Lane wrote:
> Bruce and I were discussing this the other day; it'd be pretty easy to
> make plain VACUUM start a fresh transaction immediately after it
> finishes a scan heap/clean indexes/clean heap cycle.  The infrastructure
> for this (in particular, session-level locks that won't be lost by
> closing the xact) is all there.  You'd have to figure out how often to
> start a new xact ... every cycle is probably too often, at least for
> smaller maintenance_work_mem settings ... but it'd not be hard or

If maintenance_work_mem is small you're likely to have poor performance
anyway; I'm suspicious that the overhead of starting a new xact would be
all that important. If you care about performance, you'll probably have
increased maintenance_work_mem anyway.
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461


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