Re: [Proposal] Global temporary tables

On Mon, Jan 27, 2020 at 4:11 AM Konstantin Knizhnik
<k(dot)knizhnik(at)postgrespro(dot)ru> wrote:
> I do not see any reasons to allow build local indexes for global table. Yes,it can happen that some session will have small amount of data in particular GTT and another - small amount of data in this table. But if access pattern is the same (and nature of GTT assumes it), then index in either appreciate, either useless in both cases.

I agree. I think allowing different backends to have different indexes
is overly complicated.

Regarding another point that was raised, I think it's not a good idea
to prohibit DDL on global temporary tables altogether. It should be
fine to change things when no sessions are using the GTT. Going
further and allowing changes when there are attached sessions would be
nice, but I think we shouldn't try. Getting this feature committed is
going to be a huge amount of work with even a minimal feature set;
complicating the problem by adding what are essentially new
DDL-concurrency features on top of the basic feature seems very much
unwise.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company