Re: Virtual generated columns

On Wed, 8 Jan 2025 at 16:14, Peter Eisentraut <peter@eisentraut.org> wrote:
>
> Here is a new patch version

In expand_generated_columns_in_expr():

+       RangeTblEntry *rte;
+
+       rte = makeNode(RangeTblEntry);
+       rte->relid = RelationGetRelid(rel);
+
+       node = expand_generated_columns_internal(node, rel, rt_index, rte);

This dummy RTE is a bit too minimal.

I think it should explicitly set rte->rtekind to RTE_RELATION, even
though that's technically not necessary since RTE_RELATION is zero.

In addition, it needs to set rte->eref, because expandRTE() (called
from ReplaceVarsFromTargetList()) needs that when expanding whole-row
variables. Here's a simple reproducer which crashes:

CREATE TABLE foo (a int, b int GENERATED ALWAYS AS (a*2) VIRTUAL);
ALTER TABLE foo ADD CONSTRAINT foo_check CHECK (foo IS NOT NULL);

Regards,
Dean