prashantwason commented on a change in pull request #1457: [HUDI-741] Added checks to validate Hoodie's schema evolution. URL: https://github.com/apache/incubator-hudi/pull/1457#discussion_r406978802
########## File path: hudi-common/src/main/java/org/apache/hudi/common/table/TableSchemaResolver.java ########## @@ -0,0 +1,274 @@ +/* + * 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.hudi.common.table; + +import java.io.IOException; + +import org.apache.avro.Schema; +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.fs.Path; +import org.apache.hudi.common.avro.SchemaCompatibility; +import org.apache.hudi.common.model.HoodieCommitMetadata; +import org.apache.hudi.common.model.HoodieFileFormat; +import org.apache.hudi.common.model.HoodieLogFile; +import org.apache.hudi.common.table.log.HoodieLogFormat; +import org.apache.hudi.common.table.log.HoodieLogFormat.Reader; +import org.apache.hudi.common.table.log.block.HoodieAvroDataBlock; +import org.apache.hudi.common.table.log.block.HoodieLogBlock; +import org.apache.hudi.common.table.timeline.HoodieActiveTimeline; +import org.apache.hudi.common.table.timeline.HoodieInstant; +import org.apache.hudi.common.util.Option; +import org.apache.hudi.common.util.collection.Pair; +import org.apache.hudi.exception.HoodieException; +import org.apache.hudi.exception.InvalidTableException; +import org.apache.log4j.LogManager; +import org.apache.log4j.Logger; +import org.apache.parquet.avro.AvroSchemaConverter; +import org.apache.parquet.format.converter.ParquetMetadataConverter; +import org.apache.parquet.hadoop.ParquetFileReader; +import org.apache.parquet.hadoop.metadata.ParquetMetadata; +import org.apache.parquet.schema.MessageType; + +/** + * Helper class to read schema from data files and log files and to convert it between different formats. + */ +public class TableSchemaResolver { + + private static final Logger LOG = LogManager.getLogger(TableSchemaResolver.class); + private HoodieTableMetaClient metaClient; + + public TableSchemaResolver(HoodieTableMetaClient metaClient) { + this.metaClient = metaClient; + } + + /** + * Gets the schema for a hoodie table. Depending on the type of table, read from any file written in the latest + * commit. We will assume that the schema has not changed within a single atomic write. + * + * @return Parquet schema for this table + * @throws Exception + */ + public MessageType getDataSchema() throws Exception { Review comment: This simplifies the code. I have updated to use the schema from commit metadata. For MOR tables, the compaction operation also leads to a commit (.commit extension) which saves HoodieCommitMetadata but without the SCHEMA. I guess this is a miss and not as per design. I have fixed this as I test both types of tables. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
