TAJO-1511 Minimize memory usage of inMemoryTable in ExternalSortExec

tajo-common/src/main/java/org/apache/tajo/datum/DatumFactory.java

@@ -163,6 +163,8 @@ public static Datum createFromInt4(DataType type, int val) {
       return new Int4Datum(val);
     case DATE:
       return new DateDatum(val);
+    case INET4:
+      return new Inet4Datum(val);
     default:
       throw new UnsupportedOperationException("Cannot create " + type.getType().name() + " datum from INT4");
     }

tajo-common/src/main/java/org/apache/tajo/storage/EmptyTuple.java

@@ -18,6 +18,7 @@
 
 package org.apache.tajo.storage;
 
+import org.apache.tajo.common.TajoDataTypes;
 import org.apache.tajo.datum.Datum;
 import org.apache.tajo.datum.NullDatum;
 import org.apache.tajo.datum.ProtobufDatum;
@@ -50,6 +51,11 @@ public boolean contains(int fieldId) {
     return false;
   }
 
+  @Override
+  public TajoDataTypes.Type type(int fieldId) {
+    return TajoDataTypes.Type.NULL_TYPE;
+  }
+
   @Override
   public boolean isNull(int fieldid) {
     return true;

tajo-common/src/main/java/org/apache/tajo/storage/ReadableTuple.java

@@ -0,0 +1,57 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF 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.apache.tajo.storage;
+
+import org.apache.tajo.common.TajoDataTypes;
+import org.apache.tajo.datum.Datum;
+
+public interface ReadableTuple {
+
+  TajoDataTypes.Type type(int fieldId);
+
+  boolean isNull(int fieldId);
+
+  boolean getBool(int fieldId);
+
+  byte getByte(int fieldId);
+
+  char getChar(int fieldId);
+
+  byte[] getBytes(int fieldId);
+
+  short getInt2(int fieldId);
+
+  int getInt4(int fieldId);
+
+  long getInt8(int fieldId);
+
+  float getFloat4(int fieldId);
+
+  double getFloat8(int fieldId);
+
+  String getText(int fieldId);
+
+  Datum getProtobufDatum(int fieldId);
+
+  Datum getInterval(int fieldId);
+
+  char[] getUnicodeChars(int fieldId);
+
+  Datum get(int fieldId);
+}

tajo-common/src/main/java/org/apache/tajo/storage/Tuple.java

@@ -20,14 +20,12 @@
 
 import org.apache.tajo.datum.Datum;
 
-public interface Tuple extends Cloneable {
+public interface Tuple extends Cloneable, ReadableTuple {
 
 	int size();
 
 	boolean contains(int fieldid);
 
-  boolean isNull(int fieldid);
-
   @SuppressWarnings("unused")
   boolean isNotNull(int fieldid);
 
@@ -41,37 +39,9 @@ public interface Tuple extends Cloneable {
 
 	void put(Datum[] values);
 
-	Datum get(int fieldId);
-
 	void setOffset(long offset);
-
-	long getOffset();
-
-	boolean getBool(int fieldId);
 
-	byte getByte(int fieldId);
-
-  char getChar(int fieldId);
-
-	byte [] getBytes(int fieldId);
-
-	short getInt2(int fieldId);
-
-	int getInt4(int fieldId);
-
-	long getInt8(int fieldId);
-
-	float getFloat4(int fieldId);
-
-	double getFloat8(int fieldId);
-
-	String getText(int fieldId);
-
-  Datum getProtobufDatum(int fieldId);
-
-  Datum getInterval(int fieldId);
-
-  char [] getUnicodeChars(int fieldId);
+	long getOffset();
 
   Tuple clone() throws CloneNotSupportedException;
 

tajo-common/src/main/java/org/apache/tajo/storage/VTuple.java

@@ -19,6 +19,7 @@
 package org.apache.tajo.storage;
 
 import com.google.gson.annotations.Expose;
+import org.apache.tajo.common.TajoDataTypes;
 import org.apache.tajo.datum.Datum;
 import org.apache.tajo.datum.Inet4Datum;
 import org.apache.tajo.datum.IntervalDatum;
@@ -54,6 +55,11 @@ public boolean contains(int fieldId) {
 		return values[fieldId] != null;
 	}
 
+  @Override
+  public TajoDataTypes.Type type(int fieldId) {
+    return values[fieldId] == null ? TajoDataTypes.Type.NULL_TYPE : values[fieldId].type();
+  }
+
   @Override
   public boolean isNull(int fieldid) {
     return values[fieldid] == null || values[fieldid].isNull();

tajo-common/src/main/java/org/apache/tajo/util/ClassSize.java

@@ -121,6 +121,9 @@ public class ClassSize {
   /** Overhead for KeyValueSkipListSet */
   public static final int KEYVALUE_SKIPLIST_SET;
 
+  /** Overhead for BitSet */
+  public static final int BITSET;
+
   /* Are we running on jdk7? */
   private static final boolean JDK7;
   static {
@@ -212,6 +215,8 @@ public class ClassSize {
     TIMERANGE_TRACKER = align(ClassSize.OBJECT + Bytes.SIZEOF_LONG * 2);
 
     KEYVALUE_SKIPLIST_SET = align(OBJECT + REFERENCE);
+
+    BITSET = align(ARRAY + Bytes.SIZEOF_INT + Bytes.SIZEOF_BOOLEAN);
   }
 
   /**