Re: Please consider removing "select count(*)..."
От | Andreas Pflug |
---|---|
Тема | Re: Please consider removing "select count(*)..." |
Дата | |
Msg-id | 3ECEA54B.70406@web.de обсуждение исходный текст |
Ответ на | Re: Please consider removing "select count(*)..." ("Dave Page" <dpage@vale-housing.co.uk>) |
Список | pgadmin-hackers |
Dave Page wrote: > > >>-----Original Message----- >>From: Yurgis Baykshtis [mailto:ybaykshtis@aurigin.com] >>Sent: 23 May 2003 19:46 >>To: pgadmin-hackers@postgresql.org >>Subject: [pgadmin-hackers] Please consider removing "select >>count(*)..." >> >> >>In both pgAdmin 2 and 3, whenever I click on a table node in >>the object tree, for a table with relatively big number of >>rows, it's taking a very long time to update the property >>panel (up to a few minutes with very high CPU load by the >>postgres process) making practically impossible usage of the >>tool. The reason is in the "select count(*)" query pgAdmin >>use to get table row count. >>I am not sure whether there is another way to count table >>rows in Postgres, but I see it does not like 'select >>count(*)' much for large tables. >> >>I just commented out this query for myself forcing row count >>field to be always zero and it works just fine for me. >> >> > >Hi Yurgis, > >I've now added an option for this to the pgAdmin III CVS. > > Didn't think this would be an issue so early. I planned to implement this with a threshold level. We have rowsEstimated, which should (hopefully) be more or less up-to-date if VACUUMed properly, and if e.g. 100,000 rows (configurable) are exceeded a count(*) is suppressed and only performed on explicit refresh. Yurgis, you seem to have large tables, which default threshold seems reasonable to you? 10k rows? 100k? Regards, Andreas
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