Re: Virtual generated columns

jian he <jian.universality@gmail.com>

From: jian he <jian.universality@gmail.com>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>, Dean Rasheed <dean.a.rasheed@gmail.com>
Date: 2024-12-04T04:55:23Z
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__.

Attachments

On Fri, Nov 29, 2024 at 6:13 PM Peter Eisentraut <peter@eisentraut.org> wrote:
>
> - Added support for virtual columns in trigger column lists.  (For that,
> I renamed ExecInitStoredGenerated() to ExecInitGenerated(), which
> handles the computation of ri_extraUpdatedCols.)
>

why not duplicate some code from ExecInitStoredGenerated to
ExecGetExtraUpdatedCols?

* now the expression is that something initiated for the virtual
generated column. which may not be necessary for virtual columns.
let's make ResultRelInfo->ri_GeneratedExprsI,
ResultRelInfo->ri_GeneratedExprsU be NULL for virtual columns.

currently it may look like this:
(gdb) p resultRelInfo->ri_GeneratedExprsU
$20 = (ExprState **) 0x34f9638
(gdb) p resultRelInfo->ri_GeneratedExprsU[0]
$21 = (ExprState *) 0x0
(gdb) p resultRelInfo->ri_GeneratedExprsU[1]
$22 = (ExprState *) 0x0
(gdb) p resultRelInfo->ri_GeneratedExprsU[2]
$23 = (ExprState *) 0x40

* ExecInitStoredGenerated main used in ExecComputeStoredGenerated.
* we also need to slightly change ExecInitGenerated's comments.
* in InitResultRelInfo, do we need explicit set ri_Generated_valid to false?
* duplicate code won't have big performance issues, since
build_column_default will take most of the time.


the attached patch makes ExecInitStoredGenerated as is;
duplicate some code from ExecInitStoredGenerated to ExecGetExtraUpdatedCols.