Re: Bug #790: Optimizer does not want to use an index for large table

pgsql-bugs@postgresql.org writes:
> CREATE TABLE obj_props(obj_id int8,name text,value text);
                         ^^^^^^^^^^^

You need an explicit cast, like this:

EXPLAIN SELECT name,value FROM obj_props WHERE obj_id = 100::int8;

because the planner is not smart about converting cross-datatype
comparisons into indexscans, and unadorned "100" is taken as int4.

I think we will finally have a fix for this in 7.4.

            regards, tom lane