Devrim Gündüz <devrim@gunduz.org> writes:
> They wanted to change id column from uuid to int, so created this func first:
> CREATE FUNCTION foofunc_id_uuidtoint(chartoconvert uuid) RETURNS integer
> LANGUAGE sql IMMUTABLE STRICT
> AS $_$
> SELECT newid FROM foo1 WHERE tempuuid = $1 LIMIT 1;
> $_$;
> and ran this:
> ALTER TABLE foo1 ALTER COLUMN id TYPE INTEGER USING
> foofunc_id_uuidtoint(tempuuid);
> This command crashed postmaster.
The above isn't ever likely to work for any large value of "work",
because the function would be confused about what the table rowtype
is. I thought we had adequate defenses in there to throw an error
if you try to access a table that's in the middle of being altered,
but apparently this case isn't covered.
Why didn't they just doALTER TABLE foo1 ALTER COLUMN id TYPE INTEGER USING newid;
? The intermediate function sure seems like the hard way.
regards, tom lane
