Re: Select query takes long to execute
От | Nikolaus Dilger |
---|---|
Тема | Re: Select query takes long to execute |
Дата | |
Msg-id | 20030529194451.24416.h006.c001.wm@mail.dilger.cc.criticalpath.net обсуждение исходный текст |
Ответ на | Select query takes long to execute ("Kevin Schroeder" <mirage@mirageworks.com>) |
Список | pgsql-performance |
Kevin, How about creating a new index just on column6? That should be much more effective than the multicolumn index. Regards, Nikolaus On Thu, 29 May 2003 08:58:07 -0500, "Kevin Schroeder" wrote: > > Hello, > I'm running a simple query on a table and I'm > getting a very long > response time. The table has 56,000 rows in it. It > has a full text field, > but it is not being referenced in this query. The > query I'm running is > > select row_key, column1, column2, column3, column4, > column5 from table1 > where column6 = 1 order by column3 desc limit 21; > > There is an index on the table > > message_index btree (column6, column3, column7) > > Column 3 is a date type, column 6 is an integer and > column 7 is unused in > this query. > > The total query time is 6 seconds, but I can bring that > down to 4.5 if I > append "offset 0" to the end of the query. By checking > query using "explain > analyze" it shows that it is using the index. > > If anyone has any ideas as to why the query is taking > so long and what I can > do to make it more efficient I would love to know. > > Thanks > Kevin > > > ---------------------------(end of > broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org
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