Re: Seq scan vs index scan

> On Mar 22, 2024, at 20:55, arun chirappurath <arunsnmimt(at)gmail(dot)com> wrote:
> I am trying to force query to use indexes using query hints.

PostgreSQL does not have query hints. Enabling index scans using parameters doesn't *disable* other types of query nodes.

You can disable sequential scans using:

SET enable_seqscan = off;

... but more importantly, why do you want to force an index scan? Generally, PostgreSQL will pick a sequential scan over an index scan if the table is small, or the number of rows that come back from the query are a significant percentage of the rows of the table.

If you would like a more detailed answer, it would be a good idea to post an execution plan of the query with:

EXPLAIN ANALYZE SELECT * FROM users WHERE username = 'example_username';