pgsql-bugs@postgresql.org writes:
> explain select * from cim where utod_cim_id=0;
> NOTICE: QUERY PLAN:
> Seq Scan on cim (cost=0.00..6555.41 rows=253633 width=118)
> The query optimizer does not use my index..
How many rows are there where utod_cim_id=0? The planner guesses that
there are a lot (253633, to be exact) and concludes that using the index
is not profitable for this query.
regards, tom lane