|
the columns referenced in the predicate need to reference columns whichimplement indexes to avert FTS Anyone else? Martin ______________________________________________ Disclaimer and confidentiality note Everything in this e-mail and any attachments relates to the official business of Sender. This transmission is of a confidential nature and Sender does not endorse distribution to any party other than intended recipient. Sender does not necessarily endorse content contained within this transmission. > Date: Thu, 14 Aug 2008 14:57:09 +0400 > From: dteslenko@xxxxxxxxx > To: pgsql-general@xxxxxxxxxxxxxx > Subject: [GENERAL] Strange query plan > > Hello! > > I have following table: > > CREATE TABLE table1 ( > field1 INTEGER NOT NULL, > field2 INTEGER NOT NULL, > field3 CHARACTER(30), > ... some more numeric fields) > > I have also those indexes: > > CREATE UNIQUE INDEX idx1 ON table1 USING btree (field3, field2, field1) > CREATE INDEX idx2 ON table1 USING btree (field1, field3) > > Then I query this table with something like this: > > SELECT SUM(...) FROM table1 WHERE field3 = 'ABC' AND field1 <> 1 > GROUP BY field2 > > And planner picks up a sequential scan of a table. Why does he? > > -- > A: Because it messes up the order in which people normally read text. > Q: Why is top-posting such a bad thing? > A: Top-posting. > Q: What is the most annoying thing in e-mail? > > -- > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general Got Game? Win Prizes in the Windows Live Hotmail Mobile Summer Games Trivia Contest Find out how. |
