Add a syntax to create Incrementally Maintainable Materialized Views

Allow to create Incrementally Maintainable Materialized View (IMMV)
by using INCREMENTAL option in CREATE MATERIALIZED VIEW command
as follow:

     CREATE [INCREMANTAL] MATERIALIZED VIEW xxxxx AS SELECT ....;

Author: yugo-n

src/backend/parser/gram.y

@@ -491,6 +491,7 @@ static void check_expressions_in_partition_key(PartitionSpec *spec, core_yyscan_
 
 %type <range>	OptTempTableName
 %type <into>	into_clause create_as_target create_mv_target
+%type <boolean>	incremental
 
 %type <defelt>	createfunc_opt_item common_func_opt_item dostmt_opt_item
 %type <fun_param> func_arg func_arg_with_default table_func_column aggr_arg
@@ -769,7 +770,7 @@ static void check_expressions_in_partition_key(PartitionSpec *spec, core_yyscan_
 	HANDLER HAVING HEADER_P HOLD HOUR_P
 
 	IDENTITY_P IF_P ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IMPORT_P IN_P INCLUDE
-	INCLUDING INCREMENT INDEX INDEXES INHERIT INHERITS INITIALLY INLINE_P
+	INCLUDING INCREMENT INCREMENTAL INDEX INDEXES INHERIT INHERITS INITIALLY INLINE_P
 	INNER_P INOUT INPUT_P INSENSITIVE INSERT INSTEAD INT_P INTEGER
 	INTERSECT INTERVAL INTO INVOKER IS ISNULL ISOLATION
 
@@ -6839,31 +6840,33 @@ ext_opt_encoding_item:
  *****************************************************************************/
 
 CreateMatViewStmt:
-		CREATE OptNoLog MATERIALIZED VIEW create_mv_target AS SelectStmt opt_with_data OptDistributedBy
+		CREATE OptNoLog incremental MATERIALIZED VIEW create_mv_target AS SelectStmt opt_with_data OptDistributedBy
 				{
 					CreateTableAsStmt *ctas = makeNode(CreateTableAsStmt);
-					ctas->query = $7;
-					ctas->into = $5;
+					ctas->query = $8;
+					ctas->into = $6;
 					ctas->objtype = OBJECT_MATVIEW;
 					ctas->is_select_into = false;
 					ctas->if_not_exists = false;
 					/* cram additional flags into the IntoClause */
-					$5->rel->relpersistence = $2;
-					$5->skipData = !($8);
-					ctas->into->distributedBy = $9;
+					$6->rel->relpersistence = $2;
+					$6->skipData = !($9);
+					$6->ivm = $3;
+					ctas->into->distributedBy = $10;
 					$$ = (Node *) ctas;
 				}
-		| CREATE OptNoLog MATERIALIZED VIEW IF_P NOT EXISTS create_mv_target AS SelectStmt opt_with_data
+		| CREATE OptNoLog incremental MATERIALIZED VIEW IF_P NOT EXISTS create_mv_target AS SelectStmt opt_with_data
 				{
 					CreateTableAsStmt *ctas = makeNode(CreateTableAsStmt);
-					ctas->query = $10;
-					ctas->into = $8;
+					ctas->query = $11;
+					ctas->into = $9;
 					ctas->objtype = OBJECT_MATVIEW;
 					ctas->is_select_into = false;
 					ctas->if_not_exists = true;
 					/* cram additional flags into the IntoClause */
-					$8->rel->relpersistence = $2;
-					$8->skipData = !($11);
+					$9->rel->relpersistence = $2;
+					$9->skipData = !($12);
+					$9->ivm = $3;
 					$$ = (Node *) ctas;
 				}
 		;
@@ -6880,11 +6883,16 @@ create_mv_target:
 					$$->tableSpaceName = $5;
 					$$->viewQuery = NULL;		/* filled at analysis time */
 					$$->skipData = false;		/* might get changed later */
+					$$->ivm = false;
 
 					$$->accessMethod = greenplumLegacyAOoptions($$->accessMethod, &$$->options);
 				}
 		;
 
+incremental:	INCREMENTAL					{ $$ = true; }
+			| /*EMPTY*/						{ $$ = false; }
+		;
+
 OptNoLog:	UNLOGGED					{ $$ = RELPERSISTENCE_UNLOGGED; }
 			| /*EMPTY*/					{ $$ = RELPERSISTENCE_PERMANENT; }
 		;
@@ -18794,6 +18802,7 @@ unreserved_keyword:
 			| INCLUDING
 			| INCLUSIVE
 			| INCREMENT
+			| INCREMENTAL
 			| INDEX
 			| INDEXES
 			| INHERIT
@@ -19730,6 +19739,7 @@ bare_label_keyword:
 			| INCLUDING
 			| INCLUSIVE
 			| INCREMENT
+			| INCREMENTAL
 			| INDEX
 			| INDEXES
 			| INHERIT

src/include/nodes/primnodes.h

@@ -122,6 +122,7 @@ typedef struct IntoClause
 	Node	   *viewQuery;		/* materialized view's SELECT query */
 	bool		skipData;		/* true for WITH NO DATA */
 	Node       *distributedBy;  /* GPDB: columns to distribubte the data on. */
+	bool            ivm;		/* true for WITH IVM */
 } IntoClause;
 
 typedef struct CopyIntoClause

src/include/parser/kwlist.h

@@ -232,6 +232,7 @@ PG_KEYWORD("include", INCLUDE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("including", INCLUDING, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("inclusive", INCLUSIVE, UNRESERVED_KEYWORD, BARE_LABEL)    /* GPDB */
 PG_KEYWORD("increment", INCREMENT, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("incremental", INCREMENTAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("index", INDEX, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("indexes", INDEXES, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("inherit", INHERIT, UNRESERVED_KEYWORD, BARE_LABEL)