Re: Inverse of pg_get_serial_sequence?

On 2014-08-29 17:55:38 -0700, David G Johnston wrote:
> Andres Freund-3 wrote
> > Hi,
> >
> > We have pg_get_serial_sequence() mapping (relation, colum) to the
> > sequence. What I'm missing right now is the inverse. I.e. given a
> > sequence tell me the owner.
> > describe.c has a query for that, and it's not too hard to write, but it
> > still seems 'unfriendly' not to provide it.
> >
> > Does anybody dislike adding a function for that?
> >
> >
> > I can't really think of a good name (not that pg_get_serial_sequence is
> > well named). pg_get_serial_sequence_owner(serial regclass, OUT rel
> > regclass, OUT colname name) maybe?
>
> On a pure consistency basis: pg_get_sequence_serial(...) [though probably
> plural: _serials(...)]

Yea, but that's just horrid.

> I'd drop the serial part altogether for the more appropriate:
>
> pg_get_sequence_ownedby(...)

My problem is that that possibly be confused with the user owning the
sequence :/

> Reminder: sequences can be unowned.

Don't you say.

> Ownership and usage via default are separate things though: do you have need
> to know all users of a sequence or only the single one that is defined as
> it's owner?

I'd rather know all its users, but that's not really possible in the
general case without guessing. I'll settle for the column that's
declared as owning it. Even if we had a interface for guessing I'd not
want it to be the same as the one returning the declared owner.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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