Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/5758#discussion_r179182994
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/descriptors/TableDescriptor.scala
---
@@ -0,0 +1,75 @@
+/*
+ * 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.descriptors
+
+import org.apache.flink.table.descriptors.DescriptorProperties.toScala
+import
org.apache.flink.table.descriptors.StatisticsValidator.{STATISTICS_COLUMNS,
STATISTICS_ROW_COUNT, readColumnStats}
+import org.apache.flink.table.plan.stats.TableStats
+
+import scala.collection.JavaConverters._
+
+/**
+ * Common class for all descriptors describing table sources and sinks.
+ */
+abstract class TableDescriptor extends Descriptor {
+
+ protected var connectorDescriptor: Option[ConnectorDescriptor] = None
+ protected var formatDescriptor: Option[FormatDescriptor] = None
+ protected var schemaDescriptor: Option[Schema] = None
+ protected var statisticsDescriptor: Option[Statistics] = None
--- End diff --
Thanks for pointing this out. You are right. Sinks can have a schema but no
statistics. I was just wondering if we really need most of the refactorings in
this PR. We need to rework the `TableSourceDescriptor` class in the near future
because a Java user can access all `protected` field which is not very nice API
design.
---
