PG17 compatibility: Fix Test Failure in local_dist_join_mixed (#7731)

PostgreSQL 16 adds an extra condition (id IS NOT NULL) to the subquery.
This condition is likely used to ensure that no null values are
processed in the subquery. Instead of using the condition id IS NOT
NULL, PostgreSQL 17 generates the subplan with a trivial condition
(WHERE true), indicating that it does not need to explicitly check for
non-null values.

PostgreSQL 17 likely includes optimizations to handle null checks more
efficiently. The WHERE (id IS NOT NULL) condition that was present in
PostgreSQL 16 may now be considered redundant by the planner, as it is
implicitly handled by the query execution engine.

postgres/postgres@b262ad44

```diff
 SELECT
        foo1.id
    FROM
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo9,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo8,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo7,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo6,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo5,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo4,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo3,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo2,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo10,
 (SELECT local.id, local.title FROM local, distributed WHERE local.id = distributed.id ) as foo1
 WHERE
  foo1.id =  foo9.id AND
  foo1.id =  foo8.id AND
  foo1.id =  foo7.id AND
  foo1.id =  foo6.id AND
  foo1.id =  foo5.id AND
  foo1.id =  foo4.id AND
  foo1.id =  foo3.id AND
  foo1.id =  foo2.id AND
  foo1.id =  foo10.id AND
  foo1.id =  foo1.id
ORDER BY 1;
...
-DEBUG:  generating subplan XXX_10 for subquery SELECT id FROM local_dist_join_mixed.local WHERE (id IS NOT NULL)
+DEBUG:  generating subplan XXX_10 for subquery SELECT id FROM local_dist_join_mixed.local WHERE true
...
```

src/test/regress/bin/normalize.sed

@@ -331,3 +331,7 @@ s/\| CHECK ([a-zA-Z])(.*)/| CHECK \(\1\2\)/g
 # supported Postgres version.
 
 /DEBUG:  drop auto-cascades to type [a-zA-Z_]*.pg_temp_[0-9]*/d
+
+# Normalize subquery condition in debug logs to standardize across PostgreSQL versions #7731
+# https://github.com/postgres/postgres/commit/b262ad44
+s/for subquery SELECT id FROM local_dist_join_mixed\.local WHERE \(id IS NOT NULL\)/for subquery SELECT id FROM local_dist_join_mixed.local WHERE true/g

src/test/regress/expected/local_dist_join_mixed.out

@@ -1244,8 +1244,7 @@ DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT local.id, dis
   foo1.id =  foo4.id AND
   foo1.id =  foo3.id AND
   foo1.id =  foo2.id AND
-  foo1.id =  foo10.id AND
-  foo1.id =  foo1.id
+  foo1.id =  foo10.id
 ORDER BY 1;
 DEBUG:  Wrapping relation "local" to a subquery
 DEBUG:  generating subplan XXX_1 for subquery SELECT id FROM local_dist_join_mixed.local WHERE true
@@ -1266,8 +1265,8 @@ DEBUG:  generating subplan XXX_8 for subquery SELECT id FROM local_dist_join_mix
 DEBUG:  Wrapping relation "local" to a subquery
 DEBUG:  generating subplan XXX_9 for subquery SELECT id FROM local_dist_join_mixed.local WHERE true
 DEBUG:  Wrapping relation "local" to a subquery
-DEBUG:  generating subplan XXX_10 for subquery SELECT id FROM local_dist_join_mixed.local WHERE (id IS NOT NULL)
-DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT foo1.id FROM (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo9, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo8, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_3'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo7, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_4'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo6, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_5'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo5, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_6'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo4, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_7'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo3, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_8'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo2, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_9'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo10, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_10'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo1 WHERE ((foo1.id OPERATOR(pg_catalog.=) foo9.id) AND (foo1.id OPERATOR(pg_catalog.=) foo8.id) AND (foo1.id OPERATOR(pg_catalog.=) foo7.id) AND (foo1.id OPERATOR(pg_catalog.=) foo6.id) AND (foo1.id OPERATOR(pg_catalog.=) foo5.id) AND (foo1.id OPERATOR(pg_catalog.=) foo4.id) AND (foo1.id OPERATOR(pg_catalog.=) foo3.id) AND (foo1.id OPERATOR(pg_catalog.=) foo2.id) AND (foo1.id OPERATOR(pg_catalog.=) foo10.id) AND (foo1.id OPERATOR(pg_catalog.=) foo1.id)) ORDER BY foo1.id
+DEBUG:  generating subplan XXX_10 for subquery SELECT id FROM local_dist_join_mixed.local WHERE true
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT foo1.id FROM (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo9, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo8, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_3'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo7, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_4'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo6, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_5'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo5, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_6'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo4, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_7'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo3, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_8'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo2, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_9'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo10, (SELECT local.id, local.title FROM (SELECT NULL::integer AS "dummy-1", local_1.id, NULL::integer AS "dummy-3", NULL::text AS title, NULL::integer AS "dummy-5" FROM (SELECT intermediate_result.id FROM read_intermediate_result('XXX_10'::text, 'binary'::citus_copy_format) intermediate_result(id bigint)) local_1) local, local_dist_join_mixed.distributed WHERE (local.id OPERATOR(pg_catalog.=) distributed.id)) foo1 WHERE ((foo1.id OPERATOR(pg_catalog.=) foo9.id) AND (foo1.id OPERATOR(pg_catalog.=) foo8.id) AND (foo1.id OPERATOR(pg_catalog.=) foo7.id) AND (foo1.id OPERATOR(pg_catalog.=) foo6.id) AND (foo1.id OPERATOR(pg_catalog.=) foo5.id) AND (foo1.id OPERATOR(pg_catalog.=) foo4.id) AND (foo1.id OPERATOR(pg_catalog.=) foo3.id) AND (foo1.id OPERATOR(pg_catalog.=) foo2.id) AND (foo1.id OPERATOR(pg_catalog.=) foo10.id)) ORDER BY foo1.id
  id
 ---------------------------------------------------------------------
    0

src/test/regress/sql/local_dist_join_mixed.sql

@@ -340,8 +340,7 @@ SELECT id, name FROM local LEFT JOIN distributed USING (id) ORDER BY 1 LIMIT 1;
   foo1.id =  foo4.id AND
   foo1.id =  foo3.id AND
   foo1.id =  foo2.id AND
-  foo1.id =  foo10.id AND
-  foo1.id =  foo1.id
+  foo1.id =  foo10.id
 ORDER BY 1;
 
 SELECT