Inline parseSelectUnionExtension() into parseSelectUnion() and optimize it

h2/src/main/org/h2/command/Parser.java

@@ -2308,39 +2308,25 @@ public class Parser {
     private Query parseSelectUnion() {
         int start = lastParseIndex;
         Query command = parseSelectSub();
-        return parseSelectUnionExtension(command, start, false);
-    }
-
-    private Query parseSelectUnionExtension(Query command, int start,
-            boolean unionOnly) {
-        while (true) {
+        for (;;) {
+            SelectUnion.UnionType type;
             if (readIf(UNION)) {
-                SelectUnion union = new SelectUnion(session, command);
                 if (readIf(ALL)) {
-                    union.setUnionType(SelectUnion.UnionType.UNION_ALL);
+                    type = SelectUnion.UnionType.UNION_ALL;
                 } else {
                     readIf(DISTINCT);
-                    union.setUnionType(SelectUnion.UnionType.UNION);
-                }
-                union.setRight(parseSelectSub());
-                command = union;
-            } else if (readIf(MINUS) || readIf(EXCEPT)) {
-                SelectUnion union = new SelectUnion(session, command);
-                union.setUnionType(SelectUnion.UnionType.EXCEPT);
-                union.setRight(parseSelectSub());
-                command = union;
+                    type = SelectUnion.UnionType.UNION;
+                }
+            } else if (readIf(EXCEPT) || readIf(MINUS)) {
+                type = SelectUnion.UnionType.EXCEPT;
             } else if (readIf(INTERSECT)) {
-                SelectUnion union = new SelectUnion(session, command);
-                union.setUnionType(SelectUnion.UnionType.INTERSECT);
-                union.setRight(parseSelectSub());
-                command = union;
+                type = SelectUnion.UnionType.INTERSECT;
             } else {
                 break;
             }
+            command = new SelectUnion(session, type, command, parseSelectSub());
         }
-        if (!unionOnly) {
-            parseEndOfQuery(command);
-        }
+        parseEndOfQuery(command);
         setSQL(command, null, start);
         return command;
     }

h2/src/main/org/h2/command/dml/SelectUnion.java

@@ -61,7 +61,7 @@ public class SelectUnion extends Query {
         INTERSECT
     }
 
-    private UnionType unionType;
+    private final UnionType unionType;
 
     /**
      * The left hand side of the union (the first subquery).
@@ -71,7 +71,7 @@ public class SelectUnion extends Query {
     /**
      * The right hand side of the union (the second subquery).
      */
-    Query right;
+    final Query right;
 
     private ArrayList<Expression> expressions;
     private Expression[] expressionArray;
@@ -80,9 +80,11 @@ public class SelectUnion extends Query {
     private boolean isPrepared, checkInit;
     private boolean isForUpdate;
 
-    public SelectUnion(Session session, Query query) {
+    public SelectUnion(Session session, UnionType unionType, Query query, Query right) {
         super(session);
+        this.unionType = unionType;
         this.left = query;
+        this.right = right;
     }
 
     @Override
@@ -96,18 +98,10 @@ public class SelectUnion extends Query {
         right.prepareJoinBatch();
     }
 
-    public void setUnionType(UnionType type) {
-        this.unionType = type;
-    }
-
     public UnionType getUnionType() {
         return unionType;
     }
 
-    public void setRight(Query select) {
-        right = select;
-    }
-
     public Query getLeft() {
         return left;
     }