Re: pg_plan_advice

On Wed, Jan 21, 2026 at 6:52 AM Ajay Pal <ajay(dot)pal(dot)k(at)gmail(dot)com> wrote:
> Subsequent testing revealed that UNION operations involving constants
> which enforce empty subplans result in the generated partition-wise
> plan not being recognized by the planner.

Good catch, thank you. Should be fixed in this version.

Changes in v11:

- What was previously 0004 has been promoted to 0001. This is the
pgs_mask stuff to allow extensions to control the planner more easily,
which seems separately committable based on reviews to this point.
- Fixed a bug found by Jacob wherein GATHER() and some other tags
permitted multiple levels of nested sublists instead of, as intended,
only a single one.
- Added a test for that case, too.
- Fixed JOIN_ORDER(justonerel) so that it correctly reports "matched"
instead of incorrectly reporting "partially matched" even when
justonerel was part of a join problem.
- Add tests for specifying a prefix of the join order list.
- Removed an XXX comment from the join order tests that now seems bogus to me.
- Fixed a bug in pg_plan_advice_explain_text_multiline that caused it
to display nothing in text format when the label was empty, instead of
when the value was empty.
- Add COSTS OFF to various tests in syntax.sql. I initially omitted
this because I thought it wouldn't be necessary, but I should know
better.
- Add a test for EXPLAIN (PLAN_ADVICE) in non-text format.
- Add tests for SEMIJOIN_UNIQUE() and SEMIJOIN_NON_UNIQUE().
- Rewrite a bunch of buggy logic related to SEMIJOIN_UNIQUE() and
SEMIJOIN_NON_UNIQUE().
- Show the join type in pg_plan_advice.trace_mask output.
- Per this email from Ajay, apply the unique_nonjoin_rtekind() test to
elided (Merge)Append nodes as we do to non-elided ones.

--
Robert Haas
EDB: http://www.enterprisedb.com