On Monday 15 October 2001 16:12 pm, Tom Lane wrote: > Stuart Grimshaw <[EMAIL PROTECTED]> writes: > > SELECT a.category, b.headline, b.added, c.friendlyname > > FROM caturljoin as a > > INNER JOIN stories as b ON (a.url = b.source) > > INNER JOIN urllist as c ON (a.url = d.urn) > > WHERE a.category = 93 ORDER BY b.added DESC LIMIT 1; > > (I assume "d.urn" is a typo for "c.urn"...) > > The query plan you show looks pretty reasonable if the planner's row > count estimates are in the right ballpark. How many caturljoin rows > have category = 93? How many stories rows will match each caturljoin > row? How many urllist rows ditto?
There are 194 rows in caturljoin where url = 93, 29806 rows in stories will match those 194 rows and only 1 row in urllist will match. -- | Stuart Grimshaw <[EMAIL PROTECTED]> | Chief Operations Officer | Football Networks Ltd |- | t:07976 625221 | f:0870 7060260 ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
