Re: [HACKERS] Re: [SQL] Proposed Changes to PostgreSQL

> Bruce Momjian wrote:
>
> > > Well I see that pg_class has columns like "relhasindex". If we added a
> > > "relhassubclass", the overhead should be unmeasureable.
> >
> > Yes, but how do you keep that accurate? If I add indexes, then drop
> > them, does relhasindex go to false.
>
> I don't know. Does it?

Oops:

test=> create table test(x int);
CREATE
test=> create index i_test on test(x);
CREATE
test=> select relhasindex from pg_class where relname = 'test';
relhasindex
-------------
t
(1 row)

test=> drop index i_test;
DROP
test=> select relhasindex from pg_class where relname = 'test';
relhasindex
-------------
t
(1 row)

Let me add that to the TODO list.

>
> >Could you do that for relhassubclass?
>
> If we made it relnumsubclasses and incremented/decremented on
> CREATE/DROP, it seems easy in theory.

Yes, that would work. Seems hasindex has problems.

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