Re: Seq scan vs index scan

arun chirappurath <arunsnmimt@gmail.com> writes:
> I have a table named  users with index on user name.
> ...
> When I try to do below select query it's taking seq scan and query returns
> in 5ms.

5ms is an okay runtime, I would think.  Is the table empty?

> I am trying to force query to use indexes  using query hints.

The way to force it would be enable_seqscan = off.  I would not
be surprised to hear that that makes it slower, though.  The
planner will prefer not to use an index if it thinks that will
be slower, and in this case it sounds like that could be right.
(Don't ever assume that what the planner does with a small table
is what it will do with a large table.)

            regards, tom lane