Change native hash function with worker_hash

src/backend/distributed/planner/multi_router_planner.c

@@ -651,7 +651,7 @@ AddShardIntervalRestrictionToSelect(Query *subqery, ShardInterval *shardInterval
 
 	/* generate hashfunc(partCol) expression */
 	hashFunctionExpr = makeNode(FuncExpr);
-	hashFunctionExpr->funcid = typeEntry->hash_proc_finfo.fn_oid;
+	hashFunctionExpr->funcid = CitusWorkerHashFunctionId();
 	hashFunctionExpr->args = list_make1(targetPartitionColumnVar);
 
 	/* hash functions always return INT4 */

src/backend/distributed/utils/metadata_cache.c

@@ -26,8 +26,10 @@
 #include "commands/extension.h"
 #include "commands/trigger.h"
 #include "distributed/colocation_utils.h"
+#include "distributed/citus_ruleutils.h"
 #include "distributed/master_metadata_utility.h"
 #include "distributed/metadata_cache.h"
+#include "distributed/multi_logical_optimizer.h"
 #include "distributed/pg_dist_local_group.h"
 #include "distributed/pg_dist_node.h"
 #include "distributed/pg_dist_partition.h"
@@ -99,6 +101,7 @@ static Oid distShardPlacementNodeidIndexId = InvalidOid;
 static Oid distTransactionRelationId = InvalidOid;
 static Oid distTransactionGroupIndexId = InvalidOid;
 static Oid extraDataContainerFuncId = InvalidOid;
+static Oid workerHashFunctionId = InvalidOid;
 
 /* Citus extension version variables */
 bool EnableVersionChecks = true; /* version checks are enabled */
@@ -1452,6 +1455,24 @@ CitusExtraDataContainerFuncId(void)
 }
 
 
+/* return oid of the worker_hash function */
+Oid
+CitusWorkerHashFunctionId(void)
+{
+	if (workerHashFunctionId == InvalidOid)
+	{
+		Oid citusExtensionOid = get_extension_oid("citus", false);
+		Oid citusSchemaOid = get_extension_schema(citusExtensionOid);
+		char *citusSchemaName = get_namespace_name(citusSchemaOid);
+		const int argCount = 1;
+
+		workerHashFunctionId = FunctionOid(citusSchemaName, "worker_hash", argCount);
+	}
+
+	return workerHashFunctionId;
+}
+
+
 /*
  * CitusExtensionOwner() returns the owner of the 'citus' extension. That user
  * is, amongst others, used to perform actions a normal user might not be
@@ -2193,6 +2214,7 @@ InvalidateDistRelationCacheCallback(Datum argument, Oid relationId)
 		distTransactionRelationId = InvalidOid;
 		distTransactionGroupIndexId = InvalidOid;
 		extraDataContainerFuncId = InvalidOid;
+		workerHashFunctionId = InvalidOid;
 	}
 }
 

src/include/distributed/metadata_cache.h

@@ -99,6 +99,7 @@ extern Oid DistShardPlacementNodeidIndexId(void);
 
 /* function oids */
 extern Oid CitusExtraDataContainerFuncId(void);
+extern Oid CitusWorkerHashFunctionId(void);
 
 /* user related functions */
 extern Oid CitusExtensionOwner(void);

src/test/regress/sql/multi_insert_select.sql

@@ -1573,6 +1573,29 @@ INSERT INTO text_table (part_col) SELECT val FROM text_table;
 INSERT INTO text_table (part_col) SELECT val::text FROM text_table;
 insert into table_with_starts_with_defaults (b,c) select b,c FROM table_with_starts_with_defaults;
 
+-- Test on partition column without native hash function 
+CREATE TABLE raw_table
+(
+    id BIGINT,
+    time DATE
+);
+
+CREATE TABLE summary_table
+(
+    time DATE,
+    count BIGINT
+);
+
+SELECT create_distributed_table('raw_table', 'time');
+SELECT create_distributed_table('summary_table', 'time');
+
+INSERT INTO raw_table VALUES(1, '11-11-1980');
+INSERT INTO summary_table SELECT time, COUNT(*) FROM raw_table GROUP BY time;
+
+SELECT * FROM summary_table;
+
+DROP TABLE raw_table;
+DROP TABLE summary_table;
 DROP TABLE raw_events_first CASCADE;
 DROP TABLE raw_events_second;
 DROP TABLE reference_table;