employ append mode for MVPlainTempResult

h2/src/main/org/h2/mvstore/db/MVPlainTempResult.java

@@ -61,14 +61,15 @@ class MVPlainTempResult extends MVTempResult {
     MVPlainTempResult(Database database, Expression[] expressions, int visibleColumnCount) {
         super(database, expressions.length, visibleColumnCount);
         ValueDataType valueType = new ValueDataType(database.getCompareMode(), database, new int[columnCount]);
-        Builder<Long, ValueArray> builder = new MVMap.Builder<Long, ValueArray>().valueType(valueType);
+        Builder<Long, ValueArray> builder = new MVMap.Builder<Long, ValueArray>()
+                                                .valueType(valueType).singleWriter();
         map = store.openMap("tmp", builder);
     }
 
     @Override
     public int addRow(Value[] values) {
         assert parent == null;
-        map.put(counter++, ValueArray.get(values));
+        map.append(counter++, ValueArray.get(values));
         return ++rowCount;
     }
 

h2/src/main/org/h2/mvstore/db/MVTempResult.java

@@ -160,7 +160,7 @@ public abstract class MVTempResult implements ResultExternal {
     MVTempResult(Database database, int columnCount, int visibleColumnCount) {
         try {
             String fileName = FileUtils.createTempFile("h2tmp", Constants.SUFFIX_TEMP_FILE, false, true);
-            Builder builder = new MVStore.Builder().fileName(fileName);
+            Builder builder = new MVStore.Builder().fileName(fileName).cacheSize(0);
             byte[] key = database.getFileEncryptionKey();
             if (key != null) {
                 builder.encryptionKey(MVTableEngine.decodePassword(key));