Re: Virtual generated columns

Peter Eisentraut <peter@eisentraut.org>

From: Peter Eisentraut <peter@eisentraut.org>

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

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

Date: 2024-09-09T06:02:54Z

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 →

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 04.09.24 12:33, Dean Rasheed wrote:
>> I left the 0001 patch alone for now and put the new rewriting
>> implementation into 0002.  (Unfortunately, the diff is kind of useless
>> for visual inspection.)  Let me know if this matches what you had in
>> mind, please.  Also, is this the right place in fireRIRrules()?
> Yes, that's what I had in mind except that it has to be called from
> the second loop in fireRIRrules(), after any RLS policies have been
> added, because it's possible for a RLS policy expression to refer to
> virtual generated columns. It's OK to do it in the same loop that
> expands RLS policies, because such policies can only refer to columns
> of the same relation, so once the RLS policies have been expanded for
> a given relation, nothing else should get added to the query that can
> refer to columns of that relation, at that query level, so at that
> point it should be safe to expand virtual generated columns.

If I move the code like that, then the postgres_fdw test fails.  So 
there is some additional interaction there that I need to study.