Re: Add primary keys to system catalogs

Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:

> On 2021-01-17 23:07, Tom Lane wrote:

>> I've reviewed this patch.  It looks pretty solid to me, with a couple

>> trivial nits as mentioned below, and one bigger thing that's perhaps

>> in the category of bikeshedding.  Namely, do we really want to prefer

>> using the OID indexes as the primary keys?

> I chose this because the notional foreign keys point to the OID.

> If you design some basic business database with customer IDs, product 

> IDs, etc., you'd also usually make the ID the primary key, even if you 

> have, say, a unique constraint on the product name.  But this is of 

> course a matter of taste to some degree.

Fair enough.  As I said upthread, I just wanted to be sure we'd considered

the alternative.  I'm content to use the OIDs as pkeys, although I think

that decision should be explicitly recorded somewhere (cf attachment).

>> The contents of system_constraints.sql seem pretty randomly ordered,

>> and I bet the order isn't stable across machines.

> They follow the order in which the catalogs are processed byt genbki.pl. 

Looking closer, I see the data structure is an array not a hash, so

I withdraw the concern about instability.

After reading the patch again, I have a couple more nits about comments,

which I'll just present as a proposed delta patch.  Otherwise it's good.

I'll mark it RFC.

regards, tom lane