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, 55 insertions, 23 deletions

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 808ffbd075a..1a0f4623978 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.123 2000/09/29 18:21:29 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.124 2000/10/05 19:11:27 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -176,7 +176,6 @@ _copyAppend(Append *from)
 	 * ----------------
 	 */
 	Node_Copy(from, newnode, appendplans);
-	Node_Copy(from, newnode, unionrtables);
 	newnode->inheritrelid = from->inheritrelid;
 	Node_Copy(from, newnode, inheritrtable);
 
@@ -565,6 +564,33 @@ _copyUnique(Unique *from)
 	return newnode;
 }
 
+/* ----------------
+ *		_copySetOp
+ * ----------------
+ */
+static SetOp *
+_copySetOp(SetOp *from)
+{
+	SetOp	   *newnode = makeNode(SetOp);
+
+	/* ----------------
+	 *	copy node superclass fields
+	 * ----------------
+	 */
+	CopyPlanFields((Plan *) from, (Plan *) newnode);
+
+	/* ----------------
+	 *	copy remainder of node
+	 * ----------------
+	 */
+	newnode->cmd = from->cmd;
+	newnode->numCols = from->numCols;
+	newnode->dupColIdx = palloc(from->numCols * sizeof(AttrNumber));
+	memcpy(newnode->dupColIdx, from->dupColIdx, from->numCols * sizeof(AttrNumber));
+	newnode->flagColIdx = from->flagColIdx;
+
+	return newnode;
+}
 
 /* ----------------
  *		_copyHash
@@ -1696,28 +1722,26 @@ _copyQuery(Query *from)
 	newnode->isPortal = from->isPortal;
 	newnode->isBinary = from->isBinary;
 	newnode->isTemp = from->isTemp;
-	newnode->unionall = from->unionall;
 	newnode->hasAggs = from->hasAggs;
 	newnode->hasSubLinks = from->hasSubLinks;
 
 	Node_Copy(from, newnode, rtable);
 	Node_Copy(from, newnode, jointree);
 
-	Node_Copy(from, newnode, targetList);
-
 	newnode->rowMarks = listCopy(from->rowMarks);
 
-	Node_Copy(from, newnode, distinctClause);
-	Node_Copy(from, newnode, sortClause);
+	Node_Copy(from, newnode, targetList);
+
 	Node_Copy(from, newnode, groupClause);
 	Node_Copy(from, newnode, havingQual);
-
-	/* why is intersectClause missing? */
-	Node_Copy(from, newnode, unionClause);
+	Node_Copy(from, newnode, distinctClause);
+	Node_Copy(from, newnode, sortClause);
 
 	Node_Copy(from, newnode, limitOffset);
 	Node_Copy(from, newnode, limitCount);
 
+	Node_Copy(from, newnode, setOperations);
+
 	/*
 	 * We do not copy the planner internal fields: base_rel_list,
 	 * join_rel_list, equi_key_list, query_pathkeys. Not entirely clear if
@@ -1734,17 +1758,9 @@ _copyInsertStmt(InsertStmt *from)
 	
 	if (from->relname)
 		newnode->relname = pstrdup(from->relname);
-	Node_Copy(from, newnode, distinctClause);
 	Node_Copy(from, newnode, cols);
 	Node_Copy(from, newnode, targetList);
-	Node_Copy(from, newnode, fromClause);
-	Node_Copy(from, newnode, whereClause);
-	Node_Copy(from, newnode, groupClause);
-	Node_Copy(from, newnode, havingClause);
-	Node_Copy(from, newnode, unionClause);
-	newnode->unionall = from->unionall;
-	Node_Copy(from, newnode, intersectClause);
-	Node_Copy(from, newnode, forUpdate);
+	Node_Copy(from, newnode, selectStmt);
 
 	return newnode;
 }
@@ -1790,15 +1806,11 @@ _copySelectStmt(SelectStmt *from)
 	Node_Copy(from, newnode, whereClause);
 	Node_Copy(from, newnode, groupClause);
 	Node_Copy(from, newnode, havingClause);
-	Node_Copy(from, newnode, intersectClause);
-	Node_Copy(from, newnode, exceptClause);
-	Node_Copy(from, newnode, unionClause);
 	Node_Copy(from, newnode, sortClause);
 	if (from->portalname)
 		newnode->portalname = pstrdup(from->portalname);
 	newnode->binary = from->binary;
 	newnode->istemp = from->istemp;
-	newnode->unionall = from->unionall;
 	Node_Copy(from, newnode, limitOffset);
 	Node_Copy(from, newnode, limitCount);
 	Node_Copy(from, newnode, forUpdate);
@@ -1806,6 +1818,20 @@ _copySelectStmt(SelectStmt *from)
 	return newnode;
 }
 
+static SetOperationStmt *
+_copySetOperationStmt(SetOperationStmt *from)
+{
+	SetOperationStmt *newnode = makeNode(SetOperationStmt);
+	
+	newnode->op = from->op;
+	newnode->all = from->all;
+	Node_Copy(from, newnode, larg);
+	Node_Copy(from, newnode, rarg);
+	newnode->colTypes = listCopy(from->colTypes);
+
+	return newnode;
+}
+
 static AlterTableStmt *
 _copyAlterTableStmt(AlterTableStmt *from)
 {
@@ -2553,6 +2579,9 @@ copyObject(void *from)
 		case T_Unique:
 			retval = _copyUnique(from);
 			break;
+		case T_SetOp:
+			retval = _copySetOp(from);
+			break;
 		case T_Hash:
 			retval = _copyHash(from);
 			break;
@@ -2700,6 +2729,9 @@ copyObject(void *from)
 		case T_SelectStmt:
 			retval = _copySelectStmt(from);
 			break;
+		case T_SetOperationStmt:
+			retval = _copySetOperationStmt(from);
+			break;
 		case T_AlterTableStmt:
 			retval = _copyAlterTableStmt(from);
 			break;