Hi Gaël, On Fri, Aug 21, 2009 at 3:37 PM, Gaël Le Mignot<gael@xxxxxxxxxxxxxxxx> wrote: > With 8.3 :: > > Limit (cost=752.67..752.67 rows=1 width=24) > (11 rows) > > With 8.4 :: > (8 rows) Could you provide us the EXPLAIN *ANALYZE* output of both plans? >From what I can see, one of the difference is that the estimates of the number of rows are / 3 for this part of the query: 8.3 -> Bitmap Index Scan on keywords_index (cost=0.00..48.97 rows=574 width=0) 8.4 -> Bitmap Index Scan on keywords_index (cost=0.00..14.03 rows=192 width=0) It might be interesting to see if 8.4 is right or not. Before 8.4, the selectivity for full text search was a constant (as you can see it in your 8.3 plan: the number of rows are equal in both bitmap index scan). 8.4 is smarter which might lead to other plans. -- Guillaume -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
