Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/5441#discussion_r167896355
--- Diff:
flink-libraries/flink-sql-client/src/main/java/org/apache/flink/table/client/gateway/CollectTableSink.java
---
@@ -0,0 +1,116 @@
+/*
+ * 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.flink.table.client.gateway;
+
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.common.typeinfo.Types;
+import org.apache.flink.api.common.typeutils.TypeSerializer;
+import org.apache.flink.api.java.tuple.Tuple2;
+import org.apache.flink.api.java.typeutils.TupleTypeInfo;
+import org.apache.flink.streaming.api.datastream.DataStream;
+import org.apache.flink.streaming.experimental.CollectSink;
+import org.apache.flink.streaming.experimental.SocketStreamIterator;
+import org.apache.flink.table.client.SqlClientException;
+import org.apache.flink.table.sinks.RetractStreamTableSink;
+import org.apache.flink.table.sinks.TableSink;
+import org.apache.flink.types.Row;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.util.Iterator;
+
+/**
+ * Table sink for collecting the results locally.
+ */
+public class CollectTableSink implements RetractStreamTableSink<Row>,
Iterator<Tuple2<Boolean, Row>> {
--- End diff --
I would move the `Iterator` out of the `TableSink` for better separation of
concerns. A `TableSink` should only be responsible to emit the data, not for
receiving it.
---
