Github user QiangCai commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/3001#discussion_r243164638
--- Diff:
integration/presto/src/main/java/org/apache/carbondata/presto/streaming/CarbondataStreamPageSource.java
---
@@ -0,0 +1,243 @@
+/*
+ * 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.carbondata.presto.streaming;
+
+import java.io.IOException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.List;
+import java.util.Objects;
+
+import org.apache.carbondata.common.logging.LogServiceFactory;
+import org.apache.carbondata.core.cache.dictionary.Dictionary;
+import org.apache.carbondata.core.datastore.impl.FileFactory;
+import
org.apache.carbondata.core.keygenerator.directdictionary.DirectDictionaryGenerator;
+import
org.apache.carbondata.core.keygenerator.directdictionary.DirectDictionaryKeyGeneratorFactory;
+import org.apache.carbondata.core.metadata.datatype.DataType;
+import org.apache.carbondata.core.metadata.datatype.DataTypes;
+import org.apache.carbondata.core.metadata.datatype.StructField;
+import org.apache.carbondata.core.metadata.encoder.Encoding;
+import org.apache.carbondata.core.scan.model.ProjectionDimension;
+import org.apache.carbondata.core.scan.model.ProjectionMeasure;
+import org.apache.carbondata.core.scan.model.QueryModel;
+import
org.apache.carbondata.core.scan.result.vector.impl.CarbonColumnVectorImpl;
+import org.apache.carbondata.hadoop.CarbonInputSplit;
+import org.apache.carbondata.presto.CarbonDictionaryDecodeReadSupport;
+import org.apache.carbondata.presto.CarbonVectorBatch;
+import org.apache.carbondata.presto.CarbondataSplit;
+import org.apache.carbondata.presto.impl.CarbonLocalInputSplit;
+import org.apache.carbondata.presto.readers.PrestoVectorBlockBuilder;
+import
org.apache.carbondata.processing.loading.exception.CarbonDataLoadingException;
+
+import
com.facebook.presto.hadoop.$internal.com.google.common.base.Throwables;
+import com.facebook.presto.spi.ColumnHandle;
+import com.facebook.presto.spi.ConnectorPageSource;
+import com.facebook.presto.spi.Page;
+import com.facebook.presto.spi.PrestoException;
+import com.facebook.presto.spi.block.Block;
+import org.apache.hadoop.mapreduce.RecordReader;
+import org.apache.hadoop.mapreduce.TaskAttemptID;
+import org.apache.hadoop.mapreduce.TaskType;
+import org.apache.hadoop.mapreduce.task.TaskAttemptContextImpl;
+import org.apache.log4j.Logger;
+
+/**
+ * Carbondata Page Source class for custom Carbondata RecordSet Iteration.
+ */
+public class CarbondataStreamPageSource implements ConnectorPageSource {
--- End diff --
The streaming files are row format, it is hard to lazy load column data for
each column.
---
