On Monday 26 September 2011 19:39, Marc Cousin wrote: > Because Index Scans are sorted, not Bitmap Index Scans, which builds a > list of pages to visit, to be then visited by the Bitmap Heap Scan step. > > Marc. Where does this bitmap index scan come from? It seems to negate the advantages of b-tree indexes described in the section "Indexes and ORDER BY" of the manual. If I do "set enable_bitmapscan = off;" the query runs a bit faster although with a larger time range it reverts to a sequential scan. -- Anthony Shipman | Consider the set of blacklists that Anthony.Shipman@xxxxxxxxxxxxx | do not blacklist themselves... -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
