Anshaj <anshaj(at)in2m(dot)com> writes:
> when I try to do a query like
> explain analyze select * from foo where snumber > 1000;
> It do a sequence scan on table.
One-sided inequalities are frequently not selective enough to justify an
indexscan. A rule of thumb is that if the WHERE selects more than one
or two percent of the table, you will (and should) get a seqscan.
regards, tom lane