Re: query optimiser changes 6.5->7.0
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Simon Hardingham" <simon@netxtra.net>
Cc: pgsql-general@postgresql.org
Date: 2000-06-02T02:39:47Z
Lists: pgsql-general
"Simon Hardingham" <simon@netxtra.net> writes: > I have run explain on the query and it shows that it is just > performed a sequential scan on version 7.0 > Seq Scan on gazet (cost.....) > On the old version (6.5.1) it reports > Index Scan using gazet_index on gazet (cost=.... > Any suggestions as to how I can improve performance on this databases new > server? Unfortunately you have been careful to suppress any information that might actually let someone give you useful advice ;-). There are several threads in the archives about undesirable index-vs-sequential- scan choices in 7.0; check pgsql-sql as well as pgsql-general for the last month or so. Also, 7.0.1, propagating now to an archive near you, contains some fudge-factor twiddling to make it more willing to choose an indexscan. We shall soon find out whether that made things better or worse for typical uses... regards, tom lane