Make _type use doc values

core/src/main/java/org/elasticsearch/index/mapper/internal/TypeFieldMapper.java

@@ -30,6 +30,8 @@
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.Version;
 import org.elasticsearch.common.Nullable;
+import org.elasticsearch.common.logging.ESLogger;
+import org.elasticsearch.common.logging.ESLoggerFactory;
 import org.elasticsearch.common.lucene.BytesRefs;
 import org.elasticsearch.common.lucene.Lucene;
 import org.elasticsearch.common.settings.Settings;
@@ -86,7 +88,7 @@ public Builder(MappedFieldType existing) {
 
         @Override
         public TypeFieldMapper build(BuilderContext context) {
-            fieldType.setNames(new MappedFieldType.Names(indexName, indexName, name));
+            fieldType.setNames(buildNames(context));
             return new TypeFieldMapper(fieldType, context.indexSettings());
         }
     }
@@ -146,12 +148,21 @@ public Query termQuery(Object value, @Nullable QueryShardContext context) {
     }
 
     public TypeFieldMapper(Settings indexSettings, MappedFieldType existing) {
-        this(existing == null ? Defaults.FIELD_TYPE.clone() : existing.clone(),
+        this(existing == null ? defaultFieldType(indexSettings) : existing.clone(),
              indexSettings);
     }
 
     public TypeFieldMapper(MappedFieldType fieldType, Settings indexSettings) {
-        super(NAME, fieldType, Defaults.FIELD_TYPE, indexSettings);
+        super(NAME, fieldType, defaultFieldType(indexSettings), indexSettings);
+    }
+
+    private static MappedFieldType defaultFieldType(Settings indexSettings) {
+        MappedFieldType defaultFieldType = Defaults.FIELD_TYPE.clone();
+        Version indexCreated = Version.indexCreated(indexSettings);
+        if (indexCreated.onOrAfter(Version.V_2_1_0)) {
+            defaultFieldType.setHasDocValues(true);
+        }
+        return defaultFieldType;
     }
 
     @Override

core/src/test/java/org/elasticsearch/index/mapper/internal/TypeFieldMapperTests.java

@@ -0,0 +1,48 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.index.mapper.internal;
+
+import org.elasticsearch.Version;
+import org.elasticsearch.cluster.metadata.IndexMetaData;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.index.mapper.DocumentMapper;
+import org.elasticsearch.test.ESSingleNodeTestCase;
+
+public class TypeFieldMapperTests extends ESSingleNodeTestCase {
+
+    public void testDocValues() throws Exception {
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type").endObject().endObject().string();
+
+        DocumentMapper docMapper = createIndex("test").mapperService().documentMapperParser().parse(mapping);
+        TypeFieldMapper typeMapper = docMapper.rootMapper(TypeFieldMapper.class);
+        assertTrue(typeMapper.fieldType().hasDocValues());
+    }
+
+    public void testDocValuesPre21() throws Exception {
+        // between 2.0 and 2.1, doc values was disabled for _type
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type").endObject().endObject().string();
+        Settings bwcSettings = Settings.builder().put(IndexMetaData.SETTING_VERSION_CREATED, Version.V_2_0_0_beta1.id).build();
+
+        DocumentMapper docMapper = createIndex("test", bwcSettings).mapperService().documentMapperParser().parse(mapping);
+        TypeFieldMapper typeMapper = docMapper.rootMapper(TypeFieldMapper.class);
+        assertFalse(typeMapper.fieldType().hasDocValues());
+    }
+}