Ravi Kiran <ravi(dot)kolanpaka(at)gmail(dot)com> writes:
> I tried modifying the postgresql.conf file where I set the value
> enable_hashjoin=off and also enable_mergejoin=off, so that I could force
> postgres to use nested loop.
> but postgres is still using the hash join algorithm even after modifying
> the postgresql code.
Did you remember "pg_ctl reload"? enable_hashjoin=off will most certainly
work if it's active.
regards, tom lane