Re: BUG #17351: Altering a composite type created for a partitioned table can lead to a crash

PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> When executing the following queries:
> create table pt (a int, b int) partition by list (b);
> create table t(a pt, check (a = '(1, 2)'::pt));
> alter table pt alter column a type char(4);
> \d+ t
> The server crashes with the following stack:

Hmm. We really ought to reject the ALTER TABLE. We do if "pt"
is a plain table:

regression=# create table pt (a int, b int);
CREATE TABLE
regression=# create table t(a pt);
CREATE TABLE
regression=# alter table pt alter column a type char(4);
ERROR: cannot alter table "pt" because column "t.a" uses its row type

So something is mistakenly skipping that check for partitioned
tables.

I think we're also failing to worry about the rowtype of the
constant in t's check constraint; it seems like that has to
be complained of as well, even if the underyling columns
aren't of type "pt".

regards, tom lane