Re: Is temporary functions feature official/supported? Found some issues with it.

On Thu, Jan 10, 2019 at 12:45 PM Michael Paquier <michael(at)paquier(dot)xyz> wrote:
>
> On Thu, Jan 10, 2019 at 11:47:32AM +0900, Masahiko Sawada wrote:
> > Yes, I was confused that in spite of the relation is a kind of
> > database object we separate two cases, relation and database objects
> > other than relation. So I thought that we can merge these flags to
> > something like XACT_FLAGS_ACCESSEDTEMPOBJ tracking whether the
> > transaction created, locked or dropped objects such as tables,
> > functions and datatypes on a temoprary namespace.
>
> Sure. For HEAD I don't mind doing so and that makes sense. On
> back-branches though that's another story...

Agreed.

>
> > I've found a corner-case issue with this patch; this issue still
> > happens when we create the extension on the temprary namespace,
> > because it can be done without accessing the namespace if the
> > temporary namespace is already created.
> >
> > postgres(1:59232)=# create table pg_temp.e(c int);
> > CREATE TABLE
> > postgres(1:59232)=# begin;
> > BEGIN
> > postgres(1:59232)=# create extension pgcrypto schema pg_temp_3;
> > CREATE EXTENSION
> > postgres(1:59232)=# prepare transaction 'a';
> > PREPARE TRANSACTION
> > postgres(1:59232)=# create extension pgcrypto;
> > (hang..)
>
> There is a reason why I have split that part into a separate patch and
> a separate thread:
> https://commitfest.postgresql.org/22/1969/
>
> The thing is that this behavior is rather unstable, for example I bump
> easily into that:
> =# create extension dblink schema pg_temp_3;
> ERROR: 42883: function dblink_connect_u(text) does not exist

Yes, IIUC this issue happen only when creating the extension that
doesn't access the function after created it. For example, dblink does
REVOKE for dblink_connect_u() after creation.

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center