Re: Unexpected "cache lookup failed for collation 0" failure

Manuel Rigger <rigger.manuel@gmail.com> writes:
> Is the error "cache lookup failed for collation 0" in this context expected?

> CREATE TABLE t0(c0 CHAR(2) COLLATE "C", c1 CHAR(2) COLLATE "POSIX");
> INSERT INTO t0 VALUES('', '');
> SELECT * FROM t0 WHERE t0.c1 NOT IN (t0.c0); -- unexpected: cache
> lookup failed for collation 0

No, that's never expected (except maybe in concurrent-drop scenarios).

> This looks like an internal error message to me.

I get an assertion failure :-(, although the assertion is just
complaining about the same thing, ie no-collation-assigned.
Used to work before v12, too.  Looking...

            regards, tom lane