Re: more problems with count(*) on large table
От | A. Kretschmer |
---|---|
Тема | Re: more problems with count(*) on large table |
Дата | |
Msg-id | 20070928163817.GA20354@a-kretschmer.de обсуждение исходный текст |
Ответ на | more problems with count(*) on large table (Mike Charnoky <noky@nextbus.com>) |
Ответы |
Re: more problems with count(*) on large table
Re: more problems with count(*) on large table |
Список | pgsql-general |
am Fri, dem 28.09.2007, um 11:56:46 -0400 mailte Mike Charnoky folgendes: > Hi, > > I am still having problems performing a count(*) on a large table. This > > Now, certain count(*) queries are failing to complete for certain time > ranges (I killed the query after about 24 hours). The table is indexed > on a timestamp field. Here is one query that hangs: Again: an index can't help! Because of MVCC: 'select count(*)' without WHERE-condition forces an seq. table-scan. Andreas -- Andreas Kretschmer Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header) GnuPG-ID: 0x3FFF606C, privat 0x7F4584DA http://wwwkeys.de.pgp.net
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