[BABEL-4673] Support View usage for PIVOT operator

This commit fixed an issue that view cannot be created or used by stmt
with pivot operator.

Task: BABEL-4673
Signed-off-by: Yanjie Xu <[email protected]>

Author: RIC06X

src/backend/executor/functions.c

@@ -1936,6 +1936,8 @@ check_sql_fn_retval(List *queryTreeLists,
 		newquery->querySource = parse->querySource;
 		newquery->canSetTag = true;
 		newquery->targetList = upper_tlist;
+		newquery->isPivot = false;
+		newquery->pivotInfoList = NIL;
 
 		/* We need a moderately realistic colnames list for the subquery RTE */
 		colnames = NIL;

src/backend/optimizer/plan/planner.c

@@ -6553,6 +6553,8 @@ plan_cluster_use_sort(Oid tableOid, Oid indexOid)
 	/* Set up mostly-dummy planner state */
 	query = makeNode(Query);
 	query->commandType = CMD_SELECT;
+	query->isPivot = false;
+	query->pivotInfoList = NIL;
 
 	glob = makeNode(PlannerGlobal);
 
@@ -6675,7 +6677,9 @@ plan_create_index_workers(Oid tableOid, Oid indexOid)
 	/* Set up largely-dummy planner state */
 	query = makeNode(Query);
 	query->commandType = CMD_SELECT;
-
+	query->isPivot = false;
+	query->pivotInfoList = NIL;
+	
 	glob = makeNode(PlannerGlobal);
 
 	root = makeNode(PlannerInfo);

src/backend/parser/analyze.c

@@ -407,11 +407,23 @@ transformStmt(ParseState *pstate, Node *parseTree)
 				SelectStmt *n = (SelectStmt *) parseTree;
 
 				if (n->valuesLists)
+				{
 					result = transformValuesClause(pstate, n);
+					result->isPivot = false;	
+					result->pivotInfoList = NIL;
+				}
+					
 				else if (n->op == SETOP_NONE)
+				{
 					result = transformSelectStmt(pstate, n);
+				}
 				else
+				{
 					result = transformSetOperationStmt(pstate, n);
+					result->isPivot = false;	
+					result->pivotInfoList = NIL;
+				}
+					
 			}
 			break;
 
@@ -459,6 +471,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
 			break;
 	}
 
+	if (nodeTag(parseTree) != T_SelectStmt)
+	{
+		result->isPivot = false;
+		result->pivotInfoList = NIL;
+	}
 	/* Mark as original query until we learn differently */
 	result->querySource = QSRC_ORIGINAL;
 	result->canSetTag = true;
@@ -1450,9 +1467,12 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
 	/* make WINDOW info available for window functions, too */
 	pstate->p_windowdefs = stmt->windowClause;
 
+	qry->isPivot = false;
+	qry->pivotInfoList = NIL;
+	
 	if (stmt->isPivot && transform_pivot_clause_hook)
 	{
-		(*transform_pivot_clause_hook)(pstate, stmt);
+		(*transform_pivot_clause_hook)(qry, pstate, stmt);					
 	}
 
 	/* process the FROM clause */

src/backend/parser/parse_utilcmd.c

@@ -3096,6 +3096,8 @@ transformRuleStmt(RuleStmt *stmt, const char *queryString,
 		nothing_qry->rtable = pstate->p_rtable;
 		nothing_qry->rteperminfos = pstate->p_rteperminfos;
 		nothing_qry->jointree = makeFromExpr(NIL, NULL);	/* no join wanted */
+		nothing_qry->isPivot = false;
+		nothing_qry->pivotInfoList = NIL;
 
 		*actions = list_make1(nothing_qry);
 	}

src/backend/rewrite/rewriteHandler.c

@@ -48,6 +48,9 @@
 
 bbfViewHasInsteadofTrigger_hook_type bbfViewHasInsteadofTrigger_hook = NULL; /** BBF Hook to check Instead Of trigger on View */
 
+/* Hooks for restoring PIVOT info from previously created view */
+rewrite_pivot_view_hook_type rewrite_pivot_view_hook = NULL;
+
 /* We use a list of these to detect recursion in RewriteQuery */
 typedef struct rewrite_event
 {
@@ -1826,6 +1829,16 @@ ApplyRetrieveRule(Query *parsetree,
 	 */
 	rule_action = copyObject(linitial(rule->actions));
 
+	/* 
+	 * If action query is a pivot stmt, we save the pivot related info to 
+	 * tsql_outmost_context
+	 */
+	if (sql_dialect == SQL_DIALECT_TSQL && rule_action->isPivot && rewrite_pivot_view_hook)
+	{
+		/* save information to tsql_outmost_context */
+		(*rewrite_pivot_view_hook)(rule_action);
+	}
+
 	AcquireRewriteLocks(rule_action, true, (rc != NULL));
 
 	/*

src/backend/rewrite/rewriteSearchCycle.c

@@ -279,6 +279,8 @@ rewriteSearchAndCycle(CommonTableExpr *cte)
 	newq1 = makeNode(Query);
 	newq1->commandType = CMD_SELECT;
 	newq1->canSetTag = true;
+	newq1->isPivot = false;
+	newq1->pivotInfoList = NIL;
 
 	newrte = makeNode(RangeTblEntry);
 	newrte->rtekind = RTE_SUBQUERY;
@@ -366,6 +368,8 @@ rewriteSearchAndCycle(CommonTableExpr *cte)
 	newq2 = makeNode(Query);
 	newq2->commandType = CMD_SELECT;
 	newq2->canSetTag = true;
+	newq2->isPivot = false;
+	newq2->pivotInfoList = NIL;
 
 	newrte = makeNode(RangeTblEntry);
 	newrte->rtekind = RTE_SUBQUERY;

src/include/nodes/parsenodes.h

@@ -235,6 +235,9 @@ typedef struct Query
 	int			stmt_location;
 	/* length in bytes; 0 means "rest of string" */
 	int			stmt_len pg_node_attr(query_jumble_ignore);
+
+	bool		isPivot pg_node_attr(query_jumble_ignore);
+	List		*pivotInfoList pg_node_attr(query_jumble_ignore);
 } Query;
 
 

src/include/parser/analyze.h

@@ -65,7 +65,7 @@ typedef void (*pre_transform_setop_sort_clause_hook_type) (ParseState *pstate, Q
 extern PGDLLEXPORT pre_transform_setop_sort_clause_hook_type pre_transform_setop_sort_clause_hook;
 
 /* Hook for transform pivot clause in tsql select stmt */
-typedef void (*transform_pivot_clause_hook_type)(ParseState *pstate, SelectStmt *stmt);
+typedef void (*transform_pivot_clause_hook_type)(Query *qry, ParseState *pstate, SelectStmt *stmt);
 extern PGDLLEXPORT transform_pivot_clause_hook_type transform_pivot_clause_hook;
 
 extern Query *parse_analyze_fixedparams(RawStmt *parseTree, const char *sourceText,

src/include/rewrite/rewriteHandler.h

@@ -32,4 +32,8 @@ extern int	relation_is_updatable(Oid reloid,
 								  bool include_triggers,
 								  Bitmapset *include_cols);
 
+/* Hooks for restoring PIVOT info from previously created view */
+typedef void (*rewrite_pivot_view_hook_type)(Query *qry);
+extern PGDLLEXPORT rewrite_pivot_view_hook_type rewrite_pivot_view_hook;
+
 #endif							/* REWRITEHANDLER_H */