code data type is int2. I am sorry that I did not mention the version number I am using 7.4.7. Thanks, -Prasanth. Tom Lane wrote: > Prasanth <dbadmin@xxxxxxxxxxx> writes: > >>A where condition I always use is shown below. This is bringing down the number >>of rows from 6.5m to 1210. I have an index on code also. Even here it is going >>for seq scan. > > >>EXPLAIN ANALYZE SELECT count(*) fROM a where Code >2; >> QUERY PLAN >>------------------------------------------------------------------------------------------------------------------------------- >> Aggregate (cost=141321.09..141321.09 rows=1 width=0) (actual >>time=6454.063..6454.064 rows=1 loops=1) >> -> Seq Scan on a (cost=0.00..141318.40 rows=1076 width=0) (actual >>time=15.687..6453.292 rows=1210 loops=1) >> Filter: (code > 2) >> Total runtime: 6454.140 ms >>(4 rows) > > > I'm going to hazard a guess that "code" is not of type integer, and that > you're using a pre-8.0 PG release. Cross-type comparisons are not > indexable before 8.0, so you need to cast the integer constant 2 to > whatever type "code" is. > > regards, tom lane > >
