Re: Add TOAST to system tables with ACL?

On 2017-10-03 14:19:09 -0400, Tom Lane wrote:
> Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> writes:
> > This topic was already discussed (at least one time) in 2011. See [1] for
> > details. I'd like to raise that again.
>
> I'm a bit worried about adding a toast table to pg_class, and more so
> about pg_database, because both of those have to be accessed in situations
> where it's not clear that we could successfully fetch from a toast table,
> because too little of the catalog access infrastructure is alive.
>
> pg_class is probably all right as long as only the ACL field could ever
> get toasted, since it's unlikely that any low-level accesses would be
> paying attention to that field anyway.

I think relpartbound, reloptions are pretty likely to be toasted too if
the pg_class tuple is wide enough due to acls. But that seems ok.

It'd be a lot easier to test if there were an easier way to force
columns to be toasted. Sometimes I wonder about making
TOAST_TUPLE_THRESHOLD configurable...

> For pg_database, you'd have to make sure that the startup-time check of
> database CONNECT privilege still works if the ACL's been pushed out of
> line.

Yep.

Greetings,

Andres Freund