Re: totally different plan when using partitions + request

Scara Maccai wrote:
> I'm still looking into it, but it seems the difference in the 2 plans is due to the fact that when using partitions, the planner adds the time it would take to index-scan the empty "root" table.
> But that table will never contain any data...
>
> Is there any chance to have the partitioning mechanism know that a table will always contain no data, because only inheriting table will contain data?
>
> Having the planner line:
> -> Index Scan using teststscell13_pkey on teststscell13 data1 (cost=0.0..3.9 rows=1 width=16) (actual time=0.006..0.006 rows=0 loops=285)
>
> doesn't make any sense: that table will never have any data.
> I'd like to have a way to tell that to Postgresql...

It's one index probe and takes virtually no time at all. That's not your
problem.

--
Richard Huxton
Archonet Ltd