Reimplementation of UNION/INTERSECT/EXCEPT. INTERSECT/EXCEPT now meet the

SQL92 semantics, including support for ALL option.  All three can be used
in subqueries and views.  DISTINCT and ORDER BY work now in views, too.
This rewrite fixes many problems with cross-datatype UNIONs and INSERT/SELECT
where the SELECT yields different datatypes than the INSERT needs.  I did
that by making UNION subqueries and SELECT in INSERT be treated like
subselects-in-FROM, thereby allowing an extra level of targetlist where the
datatype conversions can be inserted safely.
INITDB NEEDED!

1 files changed, 27 insertions, 59 deletions

diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index bcb8e396ede..ab8779cb375 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.74 2000/09/29 18:21:29 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.75 2000/10/05 19:11:27 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -33,8 +33,6 @@
 #include "utils/datum.h"
 
 
-static bool equali(List *a, List *b);
-
 /* Macro for comparing string fields that might be NULL */
 #define equalstr(a, b)  \
 	(((a) != NULL && (b) != NULL) ? (strcmp(a, b) == 0) : (a) == (b))
@@ -600,8 +598,6 @@ _equalQuery(Query *a, Query *b)
 		return false;
 	if (a->isTemp != b->isTemp)
 		return false;
-	if (a->unionall != b->unionall)
-		return false;
 	if (a->hasAggs != b->hasAggs)
 		return false;
 	if (a->hasSubLinks != b->hasSubLinks)
@@ -610,26 +606,24 @@ _equalQuery(Query *a, Query *b)
 		return false;
 	if (!equal(a->jointree, b->jointree))
 		return false;
-	if (!equal(a->targetList, b->targetList))
-		return false;
 	if (!equali(a->rowMarks, b->rowMarks))
 		return false;
-	if (!equal(a->distinctClause, b->distinctClause))
-		return false;
-	if (!equal(a->sortClause, b->sortClause))
+	if (!equal(a->targetList, b->targetList))
 		return false;
 	if (!equal(a->groupClause, b->groupClause))
 		return false;
 	if (!equal(a->havingQual, b->havingQual))
 		return false;
-	if (!equal(a->intersectClause, b->intersectClause))
+	if (!equal(a->distinctClause, b->distinctClause))
 		return false;
-	if (!equal(a->unionClause, b->unionClause))
+	if (!equal(a->sortClause, b->sortClause))
 		return false;
 	if (!equal(a->limitOffset, b->limitOffset))
 		return false;
 	if (!equal(a->limitCount, b->limitCount))
 		return false;
+	if (!equal(a->setOperations, b->setOperations))
+		return false;
 
 	/*
 	 * We do not check the internal-to-the-planner fields: base_rel_list,
@@ -645,27 +639,11 @@ _equalInsertStmt(InsertStmt *a, InsertStmt *b)
 {
 	if (!equalstr(a->relname, b->relname))
 		return false;
-	if (!equal(a->distinctClause, b->distinctClause))
-		return false;
 	if (!equal(a->cols, b->cols))
 		return false;
 	if (!equal(a->targetList, b->targetList))
 		return false;
-	if (!equal(a->fromClause, b->fromClause))
-		return false;
-	if (!equal(a->whereClause, b->whereClause))
-		return false;
-	if (!equal(a->groupClause, b->groupClause))
-		return false;
-	if (!equal(a->havingClause, b->havingClause))
-		return false;
-	if (!equal(a->unionClause, b->unionClause))
-		return false;
-	if (a->unionall != b->unionall)
-		return false;
-	if (!equal(a->intersectClause, b->intersectClause))
-		return false;
-	if (!equal(a->forUpdate, b->forUpdate))
+	if (!equal(a->selectStmt, b->selectStmt))
 		return false;
 
 	return true;
@@ -718,12 +696,6 @@ _equalSelectStmt(SelectStmt *a, SelectStmt *b)
 		return false;
 	if (!equal(a->havingClause, b->havingClause))
 		return false;
-	if (!equal(a->intersectClause, b->intersectClause))
-		return false;
-	if (!equal(a->exceptClause, b->exceptClause))
-		return false;
-	if (!equal(a->unionClause, b->unionClause))
-		return false;
 	if (!equal(a->sortClause, b->sortClause))
 		return false;
 	if (!equalstr(a->portalname, b->portalname))
@@ -732,8 +704,6 @@ _equalSelectStmt(SelectStmt *a, SelectStmt *b)
 		return false;
 	if (a->istemp != b->istemp)
 		return false;
-	if (a->unionall != b->unionall)
-		return false;
 	if (!equal(a->limitOffset, b->limitOffset))
 		return false;
 	if (!equal(a->limitCount, b->limitCount))
@@ -745,6 +715,23 @@ _equalSelectStmt(SelectStmt *a, SelectStmt *b)
 }
 
 static bool
+_equalSetOperationStmt(SetOperationStmt *a, SetOperationStmt *b)
+{
+	if (a->op != b->op)
+		return false;
+	if (a->all != b->all)
+		return false;
+	if (!equal(a->larg, b->larg))
+		return false;
+	if (!equal(a->rarg, b->rarg))
+		return false;
+	if (!equali(a->colTypes, b->colTypes))
+		return false;
+
+	return true;
+}
+
+static bool
 _equalAlterTableStmt(AlterTableStmt *a, AlterTableStmt *b)
 {
 	if (a->subtype != b->subtype)
@@ -1929,6 +1916,9 @@ equal(void *a, void *b)
 		case T_SelectStmt:
 			retval = _equalSelectStmt(a, b);
 			break;
+		case T_SetOperationStmt:
+			retval = _equalSetOperationStmt(a, b);
+			break;
 		case T_AlterTableStmt:
 			retval = _equalAlterTableStmt(a, b);
 			break;
@@ -2159,25 +2149,3 @@ equal(void *a, void *b)
 
 	return retval;
 }
-
-/*
- * equali
- *	  compares two lists of integers
- */
-static bool
-equali(List *a, List *b)
-{
-	List	   *l;
-
-	foreach(l, a)
-	{
-		if (b == NIL)
-			return false;
-		if (lfirsti(l) != lfirsti(b))
-			return false;
-		b = lnext(b);
-	}
-	if (b != NIL)
-		return false;
-	return true;
-}