Horton

Re: Virtual generated columns

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Richard Guo <guofenglinux@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, Zhang Mingli <zmlpostgres@gmail.com>, Alexander Lakhin <exclusion@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2025-02-20T04:57:38Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Expand virtual generated columns for ALTER COLUMN TYPE

  2. Eliminate code duplication in replace_rte_variables callbacks

  3. Expand virtual generated columns in the planner

  4. Virtual generated columns

  5. Additional tests for stored generated columns

  6. Improve generated_stored test

  7. Fix handling of CREATE DOMAIN with GENERATED constraint syntax

  8. Add pg_constraint rows for not-null constraints

  9. Put generated_stored test objects in a schema

  10. Rename regress test generated to generated_stored

  11. Small code simplification

  12. Remove useless code

  13. Remove useless initializations

  14. doc: Clarify that pg_attrdef also stores generation expressions

  15. Clean out column-level pg_init_privs entries when dropping tables.

  16. Re-implement the ereport() macro using __VA_ARGS__.

On Wed, Feb 19, 2025 at 11:25 PM Dean Rasheed <dean.a.rasheed@gmail.com> wrote:
>
> On Wed, 19 Feb 2025 at 01:42, Dean Rasheed <dean.a.rasheed@gmail.com> wrote:
> >
> > One thing I don't like about this is that it's introducing more code
> > duplication between pullup_replace_vars() and
> > ReplaceVarsFromTargetList(). Those already had a lot of code in common
> > before RETURNING OLD/NEW was added, and this is duplicating even more
> > code. I think it'd be better to refactor so that they share common
> > code, since it has become quite complex, and it would be better to
> > have just one place to maintain. Attached is an updated patch doing
> > that.
> >
>
> I've been doing some more testing of this, and attached is another
> update, improving a few comments and adding regression tests based on
> the cases discussed so far here.
>

hi.
patch v4, seems still not bullet-proof.

create table t (
     a int primary key,
     b int generated always as (1 + 1),
     c int generated always as (a),
     d int generated always as (a * 10),
     e int generated always as (coalesce(a, 100))
);
insert into t values (1), (2);
select a,c from t group by grouping sets (a,c) having c = 2;
a | c
---+---
 2 |

we should expect
 a | c
---+---
   | 2