Re: [Patch] Temporary tables that do not bloat pg_catalog (a.k.a fast temp tables)

On Sat, Aug 6, 2016 at 4:05 AM, Dmitry Dolgov <9erthalion6(at)gmail(dot)com> wrote:
>> For example, suppose I create a fast temporary table and then I create a
>> functional index on the fast temporary table that uses some SQL function
>> defined in pg_proc.
> Just to clarify, did you mean something like this?
> ```
> create fast temp table fasttab(x int, s text);
> create or replace function test_function_for_index(t text) returns text as
> $$
> begin
> return lower(t);
> end;
> $$ language plpgsql immutable;
> create index fasttab_s_idx on fasttab (test_function_for_index(s));
> drop function test_function_for_index(t text);
> ```
> As far as I understand dependencies should protect in case of fasttable too,
> because everything is visible as in regular case, isn't it?

I think the whole idea of a fast temporary table is that there are no
catalog entries. If there are no catalog entries, then dependencies
are not visible. If there ARE catalog entries, to what do they refer?
Without a pg_class entry for the table, there's no table OID upon
which to depend.

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