Re: count(*) performance improvement ideas
От
Tom Lane
Тема
Re: count(*) performance improvement ideas
Дата
Msg-id
20927.1205895835@sss.pgh.pa.us
Ответ на
Re: count(*) performance improvement ideas (Stephen Denne)
Список
Дерево обсуждения
Re: count(*) performance improvement ideas "Stephen Denne" <Stephen.Denne@datamail.co.nz>
Re: count(*) performance improvement ideas Tom Lane <tgl@sss.pgh.pa.us>
Re: count(*) performance improvement ideas Magnus Hagander <magnus@hagander.net>
Re: count(*) performance improvement ideas Tom Lane <tgl@sss.pgh.pa.us>
Re: count(*) performance improvement ideas Bruce Momjian <bruce@momjian.us>
Re: count(*) performance improvement ideas Joe Conway <mail@joeconway.com>
Re: count(*) performance improvement ideas Tom Lane <tgl@sss.pgh.pa.us>
Re: count(*) performance improvement ideas "Stephen Denne" <Stephen.Denne@datamail.co.nz>
Re: count(*) performance improvement ideas Tom Lane <tgl@sss.pgh.pa.us>
Re: count(*) performance improvement ideas "Stephen Denne" <Stephen.Denne@datamail.co.nz>
Re: count(*) performance improvement ideas PFC <lists@peufeu.com>
Re: count(*) performance improvement ideas "Stephen Denne" <Stephen.Denne@datamail.co.nz>
Re: count(*) performance improvement ideas PFC <lists@peufeu.com>
Re: count(*) performance improvement ideas "Stephen Denne" <Stephen.Denne@datamail.co.nz>
Re: count(*) performance improvement ideas "Stephen Denne" <Stephen.Denne@datamail.co.nz>
Re: count(*) performance improvement ideas PFC <lists@peufeu.com>
"Stephen Denne" writes: > What I was asking about with those questions, is if a single row is inserted in transaction A, and updated 1000 times still within transaction A, then transaction A commits... does a single row version get written, or 1001, 1000 of which are removable? Umm ... AFAICS there is no need for an UPDATE to touch the count table at all. You'd only need ON INSERT and ON DELETE triggers. regards, tom lane
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