Re: Do not lock temp relations

Yes. Our implementation restrictions preclude access to the contents
of another session's temp tables, but it is not forbidden to do DDL
on them so long as no content access is required. (Without this,
it'd be problematic for example to clean out a crashed session's temp
tables. See the "orphan temporary tables" logic in autovacuum.c.)

Indeed, a potentially dangerous situation may arise when both the
autovacuum and client process attempt to delete the contents of a temporary
namespace. But there is a patch (6faca9ae2878c8f642a2e5748d2dbb2b91341bec)
that protects us from race condition in this case. -- Best regards,
Daniil Davydov.