Re: Query Plan choice with timestamps

Giorgio Valoti wrote:
> Hi, I have a timestamptz field that I want to use with a query, but I
> don’t need the full timestamp resolution, so I’ve created a
> day_trunc(timestamptz) immutable function which I’ll use with the query
> and with a new index:
>
> logs=> create index test_idx on blackbox (day_trunc(ts));
>
> However, the query plan doesn’t use the index:

Does it use it ever? e.g. with
   SELECT * FROM blackbox WHERE day_trunk(ts) = '...'

--
   Richard Huxton
   Archonet Ltd