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

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: exclusion@gmail.com
Cc: pgsql-bugs@lists.postgresql.org
Date: 2022-01-01T21:27:05Z
Lists: pgsql-bugs
PG Bug reporting form <noreply@postgresql.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



Commits

  1. Prevent altering partitioned table's rowtype, if it's used elsewhere.