connector/catalog/StagedTable.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.sql.connector.catalog;
0019
0020 import java.util.Map;
0021
0022 import org.apache.spark.annotation.Evolving;
0023 import org.apache.spark.sql.connector.expressions.Transform;
0024 import org.apache.spark.sql.connector.write.LogicalWriteInfo;
0025 import org.apache.spark.sql.types.StructType;
0026
0027 /**
0028  * Represents a table which is staged for being committed to the metastore.
0029  * <p>
0030  * This is used to implement atomic CREATE TABLE AS SELECT and REPLACE TABLE AS SELECT queries. The
0031  * planner will create one of these via
0032  * {@link StagingTableCatalog#stageCreate(Identifier, StructType, Transform[], Map)} or
0033  * {@link StagingTableCatalog#stageReplace(Identifier, StructType, Transform[], Map)} to prepare the
0034  * table for being written to. This table should usually implement {@link SupportsWrite}. A new
0035  * writer will be constructed via {@link SupportsWrite#newWriteBuilder(LogicalWriteInfo)}, and the
0036  * write will be committed. The job concludes with a call to {@link #commitStagedChanges()}, at
0037  * which point implementations are expected to commit the table's metadata into the metastore along
0038  * with the data that was written by the writes from the write builder this table created.
0039  *
0040  * @since 3.0.0
0041  */
0042 @Evolving
0043 public interface StagedTable extends Table {
0044
0045   /**
0046    * Finalize the creation or replacement of this table.
0047    */
0048   void commitStagedChanges();
0049
0050   /**
0051    * Abort the changes that were staged, both in metadata and from temporary outputs of this
0052    * table's writers.
0053    */
0054   void abortStagedChanges();
0055 }