On Tue, 2004-09-07 at 22:32, Jeremy M. Guthrie wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > I have a problem where I have the table format listed below. I have the > primary key tsyslog_id and the index built against it. However, when I > select a unique row, it will only ever do a seq scan even after I turn off > all other types except indexscan. I understand you cannot fully turn off seq > scan. ... > I cannot run vacuum more than once a day because of its heavy IO penalty. I > run analyze once an hour. However, if I run analyze then explain, I see no > difference in the planners decisions. What am I missing? > > > TSyslog=# \d syslog_tarchive; > Table "public.syslog_tarchive" > Column | Type | > Modifiers > - > ------------+------------------------+------------------------------------------------------------------------- > tsyslog_id | bigint | not null default ... > > TSyslog=# explain select * from tsyslog where tsyslog_id=431650835;
That constant is INTEGER, whereas the column is BIGINT; there is no automatic conversion in this case, so the planner does not realise the index is usable for this query (I think 8.0 solves this). Try: select * from tsyslog where tsyslog_id=431650835::BIGINT; -- Oliver Elphick [EMAIL PROTECTED] Isle of Wight http://www.lfix.co.uk/oliver GPG: 1024D/A54310EA 92C8 39E7 280E 3631 3F0E 1EC0 5664 7A2F A543 10EA ======================================== "I am crucified with Christ; nevertheless I live; yet not I, but Christ liveth in me; and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me." Galatians 2:20 ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
