Horton

Re: Virtual generated columns

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Richard Guo <guofenglinux@gmail.com>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, Zhang Mingli <zmlpostgres@gmail.com>, Alexander Lakhin <exclusion@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2025-02-24T06:50:19Z
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 Sat, Feb 22, 2025 at 11:12 PM Richard Guo <guofenglinux@gmail.com> wrote:
>
> On Sat, Feb 22, 2025 at 11:55 PM Richard Guo <guofenglinux@gmail.com> wrote:
> > Attached are the updated patches to fix all the mentioned issues.  I
> > plan to push them early next week after staring at the code for a bit
> > longer, barring any objections.
>
> Sign... I neglected to make the change in 0001 that a Var newnode
> compares its varlevelsup with 0 when deciding to wrap it in a
> ReturningExpr.  I made this change in 0002 though, so maybe we're good
> here.  Still, I'll fix this later.
>
i also noticed this issue...

some minor comments about v7.

         * In order to be able to cache the results, we always generate the
         * expansion with varlevelsup = 0.  The caller is responsible for
         * adjusting it if needed.
         *
        expandRTE(target_rte,
                  var->varno, 0 /* not varlevelsup */ ,
                  var->varreturningtype, var->location,
                  (var->vartype != RECORDOID),
                  &colnames, &fields);
the above comments should be put on top of ReplaceVarFromTargetList?
so people can easily catch it.
when using ReplaceVarFromTargetList,
they’ll be aware that they might need to call IncrementVarSublevelsUp
in the caller.



src/include/nodes/primnodes.h
 * ReturningExpr nodes never appear in a parsed Query --- they are only ever
 * inserted by the rewriter.
 */
typedef struct ReturningExpr
this comment needs to change?



on top of src/test/regress/sql/generated_virtual.sql, we have:
-- keep these tests aligned with generated_stored.sql

but gtest32 is only related to virtual generated column.
maybe add a comment saying gtest32 related tests do not
apply to stored generated column.