Re: Pg_upgrade and toast tables bug discovered

On Thu, Jul 10, 2014 at 06:17:14PM -0400, Bruce Momjian wrote:
> Well, we are going to need to call internal C functions, often bypassing
> their typical call sites and the assumption about locking, etc.  Perhaps
> this could be done from a plpgsql function.  We could add and drop a
> dummy column to force TOAST table creation --- we would then only need a
> way to detect if a function _needs_ a TOAST table, which was skipped in
> binary upgrade mode previously.
> 
> That might be a minimalistic approach.

I have thought some more on this.  I thought I would need to open
pg_class in C and do complex backend stuff, but I now realize I can do
it from libpq, and just call ALTER TABLE and I think that always
auto-checks if a TOAST table is needed.  All I have to do is query
pg_class from libpq, then construct ALTER TABLE commands for each item,
and it will optionally create the TOAST table if needed.  I just have to
use a no-op ALTER TABLE command, like SET STATISTICS.

I am in Asia the next two weeks but will work on it after I return.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + Everyone has their own god. +