Re: Virtual generated columns

Dean Rasheed <dean.a.rasheed@gmail.com>

From: Dean Rasheed <dean.a.rasheed@gmail.com>

To: Peter Eisentraut <peter@eisentraut.org>

Cc: pgsql-hackers <pgsql-hackers@postgresql.org>, jian he <jian.universality@gmail.com>

Date: 2024-11-07T10:02:34Z

Lists: pgsql-hackers

Commits

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Expand virtual generated columns for ALTER COLUMN TYPE
- 5069fef1cfae 18.0 landed
Eliminate code duplication in replace_rte_variables callbacks
- 363a6e8c6fcf 18.0 landed
Expand virtual generated columns in the planner
- 1e4351af329f 18.0 landed
Virtual generated columns
- 83ea6c54025b 18.0 landed
Additional tests for stored generated columns
- 41084409f635 18.0 landed
Improve generated_stored test
- 44b61efb7928 18.0 landed
- 86749ea3b766 18.0 landed
Fix handling of CREATE DOMAIN with GENERATED constraint syntax
- 84a67725cd11 18.0 landed
Add pg_constraint rows for not-null constraints
- 14e87ffa5c54 18.0 cited
Put generated_stored test objects in a schema
- 894be11adfa6 18.0 landed
Rename regress test generated to generated_stored
- b9ed4969250d 18.0 landed
Small code simplification
- 7ff9afbbd1df 18.0 landed
Remove useless code
- e26d313bad92 18.0 landed
Remove useless initializations
- da2aeba8f533 18.0 landed
doc: Clarify that pg_attrdef also stores generation expressions
- da486d360103 18.0 landed
Clean out column-level pg_init_privs entries when dropping tables.
- 76618097a6c0 17.0 cited
Re-implement the ereport() macro using __VA_ARGS__.
- e3a87b4991cc 13.0 cited

On Tue, 5 Nov 2024 at 16:17, Peter Eisentraut <peter@eisentraut.org> wrote:
>
> New patch version.

In expand_generated_columns_in_expr():

+        /*
+         * XXX For the benefit of triggers, make two passes, so it covers
+         * PRS2_OLD_VARNO and PRS2_NEW_VARNO.
+         */
+        node = expand_generated_columns_internal(node, rel, 1, rte);
+        node = expand_generated_columns_internal(node, rel, 2, rte);

It seems a bit messy to be doing these two passes in
expand_generated_columns_in_expr(), when it is only needed for
triggers. I think it was better the way it was in the v7 patch,
passing rt_index to expand_generated_columns_in_expr(), so that
TriggerEnabled() did this:

+            tgqual = (Node *)
expand_generated_columns_in_expr(tgqual, relinfo->ri_RelationDesc,
PRS2_OLD_VARNO);
+            tgqual = (Node *)
expand_generated_columns_in_expr(tgqual, relinfo->ri_RelationDesc,
PRS2_NEW_VARNO);

Regards,
Dean