Re: Index not used in certain nested views but not in others - Mailing list pgsql-general

From Tom Lane
Subject Re: Index not used in certain nested views but not in others
Date
Msg-id 3847.1747145566@sss.pgh.pa.us
Whole thread Raw
In response to Re: Index not used in certain nested views but not in others  (Markus Demleitner <msdemlei@ari.uni-heidelberg.de>)
List pgsql-general
Markus Demleitner <msdemlei@ari.uni-heidelberg.de> writes:
> You see, when creating the "big", 30-tables view, I do cast all
> columns to common types in the view statement that actually make up
> the view.  The original SQL fragments look like this:

>   SELECT
>     CAST(ssa_dstype AS text) AS dataproduct_type,
>     CAST(NULL AS text) AS dataproduct_subtype,
>     CAST(2 AS smallint) AS calib_level,
>     ...

> and have a common source, so I'd believe by the time the things end
> up in the view, they should type-align even though their source
> tables do not.

Oh, well, that's your problem.  The source tables' column types
need to match.  Otherwise the UNIONs don't get flattened and you
don't get indexscans.

            regards, tom lane



pgsql-general by date:

Previous
From: Magnus Hagander
Date:
Subject: Re: deb http://apt.postgresql.org/pub/repos/apt/ bookworm-pgdg main 15
Next
From: Andrej
Date:
Subject: Re: deb http://apt.postgresql.org/pub/repos/apt/ bookworm-pgdg main 15