PG17 compatibility: fix multi-1 diffs caused by PG17 optimizer enhanc…

…ements (#7769)

This fix ensures that the expected DEBUG error messages from the router
planner in `multi_router_planner`, `multi_router_planner_fast_path` and
`query_single_shard_table` are present with PG17.

In `query_single_shard_table` the diff:
```
SELECT COUNT(*) FROM citus_local_table t1
 WHERE t1.b IN (
     SELECT b+1 FROM nullkey_c1_t1 t2 WHERE t2.b = t1.a
 );
-DEBUG:  router planner does not support queries that reference non-colocated distributed tables
+DEBUG:  Local tables cannot be used in distributed queries.
```
occurred because of[ this PG17
commit](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=9f1337639)
which enables the optimizer to pull up a correlated ANY subquery to a
join. The fix inhibits subquery pull up by including a volatile function
in the predicate involving the ANY subquery, preserving the pre-PG17
optimizer treatment of the query.

In the case of `multi_router_planner` and
`multi_router_planner_fast_path` the diffs:
```
-- partition_column is null clause does not prune out any shards,
 -- all shards remain after shard pruning, not router plannable
 SELECT *
 	FROM articles_hash a
 	WHERE a.author_id is null;
-DEBUG:  Router planner cannot handle multi-shard select queries
+DEBUG:  Creating router plan
```
are because of [this PG17
commit](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=b262ad440),
which enables the optimizer to detect and remove redundant IS (NOT) NULL
expressions. The fix is to adjust the table definition so the column
used for distribution is not marked NOT NULL, thus preserving the
pre-PG17 query planning behavior.

Finallly, a rule is added to `normalize.sed` to ignore DEBUG logging in CREATE MATERIALIZED
VIEW AS statements introduced by [this PG17
commit](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=b4da732fd64);
_when creating materialized views, use REFRESH logic to load data_, a
consequence of which is that with `client_min_messages` at `DEBUG2`
Postgres emits extra detail for CREATE MATERIALIZED VIEW AS statements.
```
CREATE MATERIALIZED VIEW mv_articles_hash_empty AS
 	SELECT * FROM articles_hash WHERE author_id = 1;
 DEBUG:  Creating router plan
 DEBUG:  query has a single distribution column value: 1
+DEBUG:  drop auto-cascades to type multi_router_planner.pg_temp_61391
+DEBUG:  drop auto-cascades to type multi_router_planner.pg_temp_61391[]
```
The rule can be changed to a normalization, or possibly dropped, when 17 becomes the minimum supported version.

src/test/regress/bin/normalize.sed

@@ -324,3 +324,10 @@ s/COPY delimiter must not appear in the DEFAULT specification/COPY delimiter cha
 # we add them back for pg15,pg16 compatibility
 # e.g. change CHECK other_col >= 100 to CHECK (other_col >= 100)
 s/\| CHECK ([a-zA-Z])(.*)/| CHECK \(\1\2\)/g
+
+# pg17 change: this is a rule that ignores additional DEBUG logging
+# for CREATE MATERIALIZED VIEW (commit b4da732fd64). This could be
+# changed to a normalization rule when 17 becomes the minimum
+# supported Postgres version.
+
+/DEBUG:  drop auto-cascades to type [a-zA-Z_]*.pg_temp_[0-9]*/d

src/test/regress/expected/multi_router_planner.out

@@ -10,7 +10,7 @@ CREATE SCHEMA multi_router_planner;
 SET search_path TO multi_router_planner;
 CREATE TABLE articles_hash (
 	id bigint NOT NULL,
-	author_id bigint NOT NULL,
+	author_id bigint,
 	title varchar(20) NOT NULL,
 	word_count integer
 );

src/test/regress/expected/multi_router_planner_fast_path.out

@@ -12,7 +12,7 @@ SET citus.enable_fast_path_router_planner TO true;
 -- ===================================================================
 CREATE TABLE articles_hash (
 	id bigint NOT NULL,
-	author_id bigint NOT NULL,
+	author_id bigint,
 	title varchar(20) NOT NULL,
 	word_count integer
 );

src/test/regress/expected/query_single_shard_table.out

@@ -1183,7 +1183,7 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  skipping recursive planning for the subquery since it contains references to outer queries
 ERROR:  direct joins between distributed and local tables are not supported
 SELECT COUNT(*) FROM nullkey_c1_t1 t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM citus_local_table t2 WHERE t2.b = t1.a
 );
 DEBUG:  router planner does not support queries that reference non-colocated distributed tables
@@ -1258,7 +1258,7 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  skipping recursive planning for the subquery since it contains references to outer queries
 ERROR:  direct joins between distributed and local tables are not supported
 SELECT COUNT(*) FROM citus_local_table t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM nullkey_c1_t1 t2 WHERE t2.b = t1.a
 );
 DEBUG:  router planner does not support queries that reference non-colocated distributed tables
@@ -1312,7 +1312,7 @@ DEBUG:  skipping recursive planning for the subquery since it contains reference
 ERROR:  direct joins between distributed and local tables are not supported
 HINT:  Use CTE's or subqueries to select from local tables and use them in joins
 SELECT COUNT(*) FROM nullkey_c1_t1 t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM postgres_local_table t2 WHERE t2.b = t1.a
 );
 DEBUG:  found no worker with all shard placements
@@ -1344,7 +1344,7 @@ DEBUG:  skipping recursive planning for the subquery since it contains reference
 ERROR:  direct joins between distributed and local tables are not supported
 HINT:  Use CTE's or subqueries to select from local tables and use them in joins
 SELECT COUNT(*) FROM postgres_local_table t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM nullkey_c1_t1 t2 WHERE t2.b = t1.a
 );
 DEBUG:  found no worker with all shard placements

src/test/regress/sql/multi_router_planner.sql

@@ -15,7 +15,7 @@ SET search_path TO multi_router_planner;
 
 CREATE TABLE articles_hash (
 	id bigint NOT NULL,
-	author_id bigint NOT NULL,
+	author_id bigint,
 	title varchar(20) NOT NULL,
 	word_count integer
 );

src/test/regress/sql/multi_router_planner_fast_path.sql

@@ -18,7 +18,7 @@ SET citus.enable_fast_path_router_planner TO true;
 
 CREATE TABLE articles_hash (
 	id bigint NOT NULL,
-	author_id bigint NOT NULL,
+	author_id bigint,
 	title varchar(20) NOT NULL,
 	word_count integer
 );
@@ -803,7 +803,6 @@ CREATE MATERIALIZED VIEW mv_articles_hash_empty AS
 	SELECT * FROM articles_hash WHERE author_id = 1;
 SELECT * FROM mv_articles_hash_empty;
 
-
 SELECT id
 	FROM articles_hash
 	WHERE author_id = 1;

src/test/regress/sql/query_single_shard_table.sql

@@ -502,7 +502,7 @@ WHERE NOT EXISTS (
 );
 
 SELECT COUNT(*) FROM nullkey_c1_t1 t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM citus_local_table t2 WHERE t2.b = t1.a
 );
 
@@ -543,7 +543,7 @@ WHERE EXISTS (
 );
 
 SELECT COUNT(*) FROM citus_local_table t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM nullkey_c1_t1 t2 WHERE t2.b = t1.a
 );
 
@@ -573,7 +573,7 @@ WHERE NOT EXISTS (
 );
 
 SELECT COUNT(*) FROM nullkey_c1_t1 t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM postgres_local_table t2 WHERE t2.b = t1.a
 );
 
@@ -593,7 +593,7 @@ WHERE EXISTS (
 );
 
 SELECT COUNT(*) FROM postgres_local_table t1
-WHERE t1.b IN (
+WHERE t1.b + random() IN (
     SELECT b+1 FROM nullkey_c1_t1 t2 WHERE t2.b = t1.a
 );