Re: Add primary keys to system catalogs

On Fri, Jan 22, 2021, at 16:42, Tom Lane wrote:
>"Joel Jacobson" <joel(at)compiler(dot)org> writes:
>> I ran this query (on a patched database) to see if there are still any catalog tables without primary keys:
>> ...
>> pg_depend
>> pg_shdepend
>
>Yeah, this is noted in the patch's own regression tests.

Thanks. Looks good.

>> Wouldn't it be possible to add primary keys to these two as well?
>
>Neither of the existing indexes is suitable, not being unique.
>
>We could imagine adding a unique index across the whole column set,
>but that would be an awfully large price to pay for neatnik-ism.
>Also, at least for pg_depend (less sure about pg_shdepend), some code
>cleanup would be required, because I don't think that we try very
>hard to avoid making duplicate dependency entries. On the whole
>I feel this'd be counterproductive.
>
>regards, tom lane

I see, and I agree with you.

I'm very happy with this patch.

I've already found great use of it in a tool I'm working on:
https://github.com/truthly/pg-pit/blob/master/FUNCTIONS/add_primary_keys.sql#L23

Many thanks to all of you for all the great work!
Can't wait to use this functionality in production.

/Joel