Re: ALTER TABLE .. ALTER COLUMN .. ERROR: attribute .. has wrong type

Alvaro Herrera wrote:
> Tom Lane wrote:
>
> > We could probably fix the specific issue being seen here by passing the
> > expression tree through a suitable attno remapping,
>
> Here's a first attempt at fixing this. It makes the test pass, but I
> have the feeling that more complex ones might need more work.

Here's another one with three main differences:

1. Make the whole-row check an ereport() not elog(). You can use a
whole-row expression in USING, which makes it fire, so better make it
translatable. An artificial example is in the new regression tests,
ALTER TABLE test_type_diff2 ALTER COLUMN int_four TYPE int4 USING (pg_column_size(test_type_diff2));
but I suppose somebody with more imagination could come up with
something actually interesting.

2. The foreign table case was broken, as evidenced by the foreign_table
regression test.

3. If there is no USING expression, there is no need to do the whole
map_variable_attnos() dance.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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