Re: [EXTERNAL] Need help with performance tuning pg12 on linux

On Wed, Dec 27, 2023 at 2:11 PM Wilson, Maria Louise (LARC-E301)[RSES] <
m(dot)l(dot)wilson(at)nasa(dot)gov> wrote:

> Thanks for the reply!! Having some issues due to nulls…. Any other
> thoughts?
>
>
>
> i=# ALTER TABLE granule_file ADD PRIMARY KEY (granule_uuid, file_id);
>
> ERROR: column "granule_uuid" contains null values
>
>
>

Seems like an odd design for your table. Check if those rows with null
value make any sense for your design.

In any case, for performance, you can try a plain index:

CREATE INDEX ON granule_file (granule_uuid);

Since you are filtering for granule_uuid first, an index starting with this
column seems to make more sense (that is why I made the PK starting with it
before).

A composite index is not really necessary, but could help if you get an
index-only scan, if you wanna try:

CREATE INDEX ON granule_file (granule_uuid, file_id);

Best regards,
--
Matheus de Oliveira