Re: get_constraint_index() and conindid

On Tue, Dec 08, 2020 at 01:28:39PM -0500, Tom Lane wrote:
> Matthias van de Meent <boekewurm+postgres@gmail.com> writes:
>> On Mon, 7 Dec 2020 at 11:09, Peter Eisentraut
>> <peter.eisentraut@enterprisedb.com> wrote:
>>> get_constraint_index() does its work by going through pg_depend.  It was
>>> added before pg_constraint.conindid was added, and some callers are
>>> still not changed.  Are there reasons for that?  Probably not.  The
>>> attached patch changes get_constraint_index() to an lsyscache-style
>>> lookup instead.
> 
>> This looks quite reasonable, and it passes "make installcheck-world".
> 
> +1, LGTM.

Nice cleanup!

>> Only thing I could think of is that it maybe could use a (small)
>> comment in the message on that/why get_constraint_index is moved to
>> utils/lsyscache from catalog/dependency, as that took me some time to
>> understand.
> 
> commit message could reasonably say that maybe, but I don't think we
> need to memorialize it in a comment.  lsyscache.c *is* where one
> would expect to find a simple catalog-field-fetch function like this.
> The previous implementation was not that, so it didn't belong there.

Agreed.
--
Michael