Only consider pseudo constants for shortcuts (#4712)

It seems that we need to consider only pseudo constants while doing some
shortcuts in planning. For example there could be a false clause but it
can contribute to the result in which case it will not be a pseudo
constant.

src/backend/distributed/planner/local_distributed_join_planner.c

@@ -93,6 +93,7 @@
 #include "distributed/multi_router_planner.h"
 #include "distributed/multi_physical_planner.h"
 #include "distributed/multi_server_executor.h"
+#include "distributed/multi_router_planner.h"
 #include "distributed/query_colocation_checker.h"
 #include "distributed/query_pushdown_planning.h"
 #include "distributed/recursive_planning.h"
@@ -395,13 +396,17 @@ HasConstantFilterOnUniqueColumn(RangeTblEntry *rangeTableEntry,
 		 */
 		return false;
 	}
-	List *baseRestrictionList = relationRestriction->relOptInfo->baserestrictinfo;
+
-	List *restrictClauseList = get_all_actual_clauses(baseRestrictionList);
+	bool joinOnFalse = JoinConditionIsOnFalse(relationRestriction->relOptInfo->joininfo);
-	if (ContainsFalseClause(restrictClauseList))
+	if (joinOnFalse)
 	{
 		/* If there is a WHERE FALSE, we consider it as a constant filter. */
 		return true;
 	}
+
+	List *baseRestrictionList = relationRestriction->relOptInfo->baserestrictinfo;
+	List *restrictClauseList = get_all_actual_clauses(baseRestrictionList);
+
 	List *rteEqualityColumnsNos =
 		FetchEqualityAttrNumsForRTE((Node *) restrictClauseList);
 

src/backend/distributed/planner/multi_router_planner.c

@@ -2705,8 +2705,6 @@ TargetShardIntervalsForRestrictInfo(RelationRestrictionContext *restrictionConte
 		List *baseRestrictionList = relationRestriction->relOptInfo->baserestrictinfo;
 		List *restrictClauseList = get_all_actual_clauses(baseRestrictionList);
 		List *prunedShardIntervalList = NIL;
-		List *joinInfoList = relationRestriction->relOptInfo->joininfo;
-		List *pseudoRestrictionList = extract_actual_clauses(joinInfoList, true);
 
 		/*
 		 * Queries may have contradiction clauses like 'false', or '1=0' in
@@ -2714,8 +2712,9 @@ TargetShardIntervalsForRestrictInfo(RelationRestrictionContext *restrictionConte
 		 * inside relOptInfo->joininfo list. We treat such cases as if all
 		 * shards of the table are pruned out.
 		 */
-		bool whereFalseQuery = ContainsFalseClause(pseudoRestrictionList);
+		bool joinFalseQuery = JoinConditionIsOnFalse(
-		if (!whereFalseQuery && shardCount > 0)
+			relationRestriction->relOptInfo->joininfo);
+		if (!joinFalseQuery && shardCount > 0)
 		{
 			Const *restrictionPartitionValueConst = NULL;
 			prunedShardIntervalList = PruneShards(relationId, tableId, restrictClauseList,
@@ -2760,6 +2759,22 @@ TargetShardIntervalsForRestrictInfo(RelationRestrictionContext *restrictionConte
 }
 
 
+/*
+ * JoinConditionIsOnFalse returns true for queries that
+ * have contradiction clauses like 'false', or '1=0' in
+ * their filters. Such queries would have pseudo constant 'false'
+ * inside joininfo list.
+ */
+bool
+JoinConditionIsOnFalse(List *joinInfoList)
+{
+	List *pseudoJoinRestrictionList = extract_actual_clauses(joinInfoList, true);
+
+	bool joinFalseQuery = ContainsFalseClause(pseudoJoinRestrictionList);
+	return joinFalseQuery;
+}
+
+
 /*
  * RelationPrunesToMultipleShards returns true if the given list of
  * relation-to-shard mappings contains at least two mappings with

src/backend/distributed/planner/relation_restriction_equivalence.c

@@ -18,6 +18,7 @@
 #include "distributed/metadata_cache.h"
 #include "distributed/multi_logical_planner.h"
 #include "distributed/multi_logical_optimizer.h"
+#include "distributed/multi_router_planner.h"
 #include "distributed/pg_dist_partition.h"
 #include "distributed/query_utils.h"
 #include "distributed/relation_restriction_equivalence.h"
@@ -1859,11 +1860,10 @@ GetRestrictInfoListForRelation(RangeTblEntry *rangeTblEntry,
 	}
 
 	RelOptInfo *relOptInfo = relationRestriction->relOptInfo;
-	List *joinRestrictInfo = relOptInfo->joininfo;
 	List *baseRestrictInfo = relOptInfo->baserestrictinfo;
 
-	List *joinRestrictClauseList = get_all_actual_clauses(joinRestrictInfo);
+	bool joinConditionIsOnFalse = JoinConditionIsOnFalse(relOptInfo->joininfo);
-	if (ContainsFalseClause(joinRestrictClauseList))
+	if (joinConditionIsOnFalse)
 	{
 		/* found WHERE false, no need  to continue, we just return a false clause */
 		bool value = false;

src/include/distributed/multi_router_planner.h

@@ -97,6 +97,7 @@ extern void GenerateSingleShardRouterTaskList(Job *job,
 extern PlannedStmt * FastPathPlanner(Query *originalQuery, Query *parse, ParamListInfo
 									 boundParams);
 extern bool FastPathRouterQuery(Query *query, Node **distributionKeyValue);
+extern bool JoinConditionIsOnFalse(List *relOptInfo);
 
 
 #endif /* MULTI_ROUTER_PLANNER_H */

src/test/regress/bin/normalize.sed

@@ -188,6 +188,12 @@ s/relation with OID [0-9]+ does not exist/relation with OID XXXX does not exist/
 # ignore DEBUG1 messages that Postgres generates
 /^DEBUG:  rehashing catalog cache id [0-9]+$/d
 
+# ignore JIT related messages
+/^DEBUG:  probing availability of JIT.*/d
+/^DEBUG:  provider not available, disabling JIT for current session.*/d
+
+
+
 # ignore timing statistics for VACUUM VERBOSE
 /CPU: user: .*s, system: .*s, elapsed: .*s/d
 

src/test/regress/expected/local_table_join.out

@@ -1010,20 +1010,19 @@ UPDATE reference_table SET key = 1 FROM (SELECT * FROM postgres_table) l WHERE l
 DEBUG:  generating subplan XXX_1 for subquery SELECT key, value, value_2 FROM local_table_join.postgres_table
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: UPDATE local_table_join.reference_table SET key = 1 FROM (SELECT intermediate_result.key, intermediate_result.value, intermediate_result.value_2 FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(key integer, value text, value_2 jsonb)) l WHERE (l.key OPERATOR(pg_catalog.=) 10)
 SELECT count(*) FROM postgres_table JOIN distributed_table USING(key) WHERE FALSE;
-DEBUG:  Wrapping relation "postgres_table" to a subquery
+DEBUG:  Wrapping relation "distributed_table" to a subquery
-DEBUG:  generating subplan XXX_1 for subquery SELECT key FROM local_table_join.postgres_table WHERE false
+DEBUG:  generating subplan XXX_1 for subquery SELECT key FROM local_table_join.distributed_table WHERE false
-DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM ((SELECT postgres_table_1.key, NULL::text AS value, NULL::jsonb AS value_2 FROM (SELECT intermediate_result.key FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(key integer)) postgres_table_1) postgres_table JOIN local_table_join.distributed_table USING (key)) WHERE false
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM (local_table_join.postgres_table JOIN (SELECT distributed_table_1.key, NULL::text AS value, NULL::jsonb AS value_2 FROM (SELECT intermediate_result.key FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(key integer)) distributed_table_1) distributed_table USING (key)) WHERE false
  count
 ---------------------------------------------------------------------
      0
 (1 row)
 
 SELECT count(*) FROM (SELECT * FROM distributed_table JOIN postgres_table USING(key) WHERE false) foo JOIN local_partitioned_table USING(key);
-DEBUG:  Wrapping relation "postgres_table" to a subquery
+DEBUG:  Wrapping relation "distributed_table" to a subquery
-DEBUG:  generating subplan XXX_1 for subquery SELECT key FROM local_table_join.postgres_table WHERE false
+DEBUG:  generating subplan XXX_1 for subquery SELECT key FROM local_table_join.distributed_table WHERE false
-DEBUG:  Wrapping relation "local_partitioned_table" to a subquery
+DEBUG:  generating subplan XXX_2 for subquery SELECT distributed_table.key, distributed_table.value, distributed_table.value_2, postgres_table.value, postgres_table.value_2 FROM ((SELECT distributed_table_1.key, NULL::text AS value, NULL::jsonb AS value_2 FROM (SELECT intermediate_result.key FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(key integer)) distributed_table_1) distributed_table JOIN local_table_join.postgres_table USING (key)) WHERE false
-DEBUG:  generating subplan XXX_2 for subquery SELECT key FROM local_table_join.local_partitioned_table WHERE false
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM ((SELECT intermediate_result.key, intermediate_result.value, intermediate_result.value_2, intermediate_result.value_1 AS value, intermediate_result.value_2_1 AS value_2 FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(key integer, value text, value_2 jsonb, value_1 text, value_2_1 jsonb)) foo(key, value, value_2, value_1, value_2_1) JOIN local_table_join.local_partitioned_table USING (key))
-DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM ((SELECT distributed_table.key, distributed_table.value, distributed_table.value_2, postgres_table.value, postgres_table.value_2 FROM (local_table_join.distributed_table JOIN (SELECT postgres_table_1.key, NULL::text AS value, NULL::jsonb AS value_2 FROM (SELECT intermediate_result.key FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(key integer)) postgres_table_1) postgres_table USING (key)) WHERE false) foo(key, value, value_2, value_1, value_2_1) JOIN (SELECT local_partitioned_table_1.key, NULL::text AS value FROM (SELECT intermediate_result.key FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(key integer)) local_partitioned_table_1) local_partitioned_table USING (key))
  count
 ---------------------------------------------------------------------
      0
@@ -1506,8 +1505,111 @@ where a + b + c > 0;
      1
 (1 row)
 
+--issue 4706
+CREATE TABLE table1(a int);
+CREATE TABLE table2(a int);
+INSERT INTO table1 VALUES (1);
+INSERT INTO table2 VALUES (1);
+-- make sure all the followings give the same result as postgres tables.
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+ res
+---------------------------------------------------------------------
+   1
+(1 row)
+
 SET client_min_messages to DEBUG1;
+BEGIN;
+SELECT create_distributed_table('table1', 'a');
+NOTICE:  Copying data from local table...
+DEBUG:  Copied 1 rows
+NOTICE:  copying the data has completed
+DETAIL:  The local data in the table is no longer visible, but is still on disk.
+HINT:  To remove the local data, run: SELECT truncate_local_data_after_distributing_table($$local_table_join.table1$$)
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+DEBUG:  Wrapping relation "table2" to a subquery
+DEBUG:  generating subplan XXX_1 for subquery SELECT NULL::integer AS "dummy-1" FROM local_table_join.table2 WHERE true
+DEBUG:  Wrapping relation "table2" to a subquery
+DEBUG:  generating subplan XXX_2 for subquery SELECT NULL::integer AS "dummy-1" FROM local_table_join.table2 WHERE true
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT 1 AS res FROM ((SELECT NULL::integer AS a FROM (SELECT intermediate_result."dummy-1" FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result("dummy-1" integer)) table2_1) table2 RIGHT JOIN (SELECT 1 FROM local_table_join.table1, (SELECT NULL::integer AS a FROM (SELECT intermediate_result."dummy-1" FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result("dummy-1" integer)) table2_2) table2_1) sub1("?column?") ON (false))
+ res
+---------------------------------------------------------------------
+   1
+(1 row)
+
+ROLLBACK;
+BEGIN;
+SELECT create_distributed_table('table2', 'a');
+NOTICE:  Copying data from local table...
+DEBUG:  Copied 1 rows
+NOTICE:  copying the data has completed
+DETAIL:  The local data in the table is no longer visible, but is still on disk.
+HINT:  To remove the local data, run: SELECT truncate_local_data_after_distributing_table($$local_table_join.table2$$)
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- currently not supported
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+DEBUG:  Wrapping relation "table1" to a subquery
+DEBUG:  generating subplan XXX_1 for subquery SELECT NULL::integer AS "dummy-1" FROM local_table_join.table1 WHERE true
+DEBUG:  generating subplan XXX_2 for subquery SELECT 1 FROM (SELECT NULL::integer AS a FROM (SELECT intermediate_result."dummy-1" FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result("dummy-1" integer)) table1_1) table1, local_table_join.table2
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT 1 AS res FROM (local_table_join.table2 RIGHT JOIN (SELECT intermediate_result."?column?" FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result("?column?" integer)) sub1("?column?") ON (false))
+ERROR:  cannot pushdown the subquery
+DETAIL:  Complex subqueries and CTEs cannot be in the outer part of the outer join
+ROLLBACK;
+BEGIN;
+SELECT create_reference_table('table1');
+NOTICE:  Copying data from local table...
+DEBUG:  Copied 1 rows
+NOTICE:  copying the data has completed
+DETAIL:  The local data in the table is no longer visible, but is still on disk.
+HINT:  To remove the local data, run: SELECT truncate_local_data_after_distributing_table($$local_table_join.table1$$)
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+DEBUG:  Wrapping relation "table2" to a subquery
+DEBUG:  generating subplan XXX_1 for subquery SELECT NULL::integer AS "dummy-1" FROM local_table_join.table2 WHERE true
+DEBUG:  Wrapping relation "table2" to a subquery
+DEBUG:  generating subplan XXX_2 for subquery SELECT NULL::integer AS "dummy-1" FROM local_table_join.table2 WHERE true
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT 1 AS res FROM ((SELECT NULL::integer AS a FROM (SELECT intermediate_result."dummy-1" FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result("dummy-1" integer)) table2_1) table2 RIGHT JOIN (SELECT 1 FROM local_table_join.table1, (SELECT NULL::integer AS a FROM (SELECT intermediate_result."dummy-1" FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result("dummy-1" integer)) table2_2) table2_1) sub1("?column?") ON (false))
+ res
+---------------------------------------------------------------------
+   1
+(1 row)
+
+ROLLBACK;
+BEGIN;
+SELECT create_reference_table('table2');
+NOTICE:  Copying data from local table...
+DEBUG:  Copied 1 rows
+NOTICE:  copying the data has completed
+DETAIL:  The local data in the table is no longer visible, but is still on disk.
+HINT:  To remove the local data, run: SELECT truncate_local_data_after_distributing_table($$local_table_join.table2$$)
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+DEBUG:  Wrapping relation "table1" to a subquery
+DEBUG:  generating subplan XXX_1 for subquery SELECT NULL::integer AS "dummy-1" FROM local_table_join.table1 WHERE true
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT 1 AS res FROM (local_table_join.table2 RIGHT JOIN (SELECT 1 FROM (SELECT NULL::integer AS a FROM (SELECT intermediate_result."dummy-1" FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result("dummy-1" integer)) table1_1) table1, local_table_join.table2 table2_1) sub1("?column?") ON (false))
+ res
+---------------------------------------------------------------------
+   1
+(1 row)
+
+ROLLBACK;
 RESET client_min_messages;
 \set VERBOSITY terse
 DROP SCHEMA local_table_join CASCADE;
-NOTICE:  drop cascades to 20 other objects
+NOTICE:  drop cascades to 22 other objects

src/test/regress/sql/local_table_join.sql

@@ -437,8 +437,40 @@ select COUNT(*) from
   inner join tbl1 on (select 1 from custom_pg_type) >= d
   left join pg_dist_rebalance_strategy on 'by_shard_count' = name
 where a + b + c > 0;
+
+--issue 4706
+CREATE TABLE table1(a int);
+CREATE TABLE table2(a int);
+
+INSERT INTO table1 VALUES (1);
+INSERT INTO table2 VALUES (1);
+
+-- make sure all the followings give the same result as postgres tables.
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+
 SET client_min_messages to DEBUG1;
 
+BEGIN;
+SELECT create_distributed_table('table1', 'a');
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+ROLLBACK;
+
+BEGIN;
+SELECT create_distributed_table('table2', 'a');
+-- currently not supported
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+ROLLBACK;
+
+BEGIN;
+SELECT create_reference_table('table1');
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+ROLLBACK;
+
+BEGIN;
+SELECT create_reference_table('table2');
+SELECT 1 AS res FROM table2 RIGHT JOIN (SELECT 1 FROM table1, table2) AS sub1 ON false;
+ROLLBACK;
+
 
 RESET client_min_messages;
 \set VERBOSITY terse