am Fri, dem 10.08.2007, um 17:46:11 +0800 mailte carter ck folgendes: > Hi all, > > I am facing a performance issue here. Whenever I do a count(*) on a table > that contains about 300K records, it takes few minutes to complete. Whereas > my other application which is counting > 500K records just take less than > 10 seconds to complete. > > I have indexed all the essential columns and still it does not improve the > speed. Indexes don't help in this case, a 'select count(*)' forces a seq. scan. Do you realy need this information? An estimate for the number of rows can you find in the system catalog (reltuples in pg_class, see http://www.postgresql.org/docs/current/interactive/catalog-pg-class.html) Andreas -- Andreas Kretschmer Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header) GnuPG-ID: 0x3FFF606C, privat 0x7F4584DA http://wwwkeys.de.pgp.net ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
