xiarixiaoyao commented on a change in pull request #4910: URL: https://github.com/apache/hudi/pull/4910#discussion_r832207038
########## File path: hudi-common/src/main/java/org/apache/hudi/internal/schema/action/InternalSchemaMerger.java ########## @@ -0,0 +1,190 @@ +/* + * 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.internal.schema.action; + +import org.apache.hudi.common.util.StringUtils; +import org.apache.hudi.internal.schema.InternalSchema; +import org.apache.hudi.internal.schema.Type; +import org.apache.hudi.internal.schema.Types; + +import java.util.ArrayList; +import java.util.List; + +/** + * auxiliary class. + * help to merge file schema and query schema to produce final read schema for avro/parquet file + */ +public class InternalSchemaMerger { + private final InternalSchema fileSchema; + private final InternalSchema querySchema; + // now there exist some bugs when we use spark update/merge api, + // those operation will change col nullability from optional to required which is wrong. + // Before that bug is fixed, we need to do adapt. + // if mergeRequiredFiledForce is true, we will ignore the col's required attribute. + private final boolean ignoreRequiredAttribute; + // Whether to use column Type from file schema to read files when we find some column type has changed. Review comment: spark parquetReader need the original column type to read data, otherwise the parquetReader will failed. **eg: current column type is StringType, now we changed it to decimalType,** we should not pass decimalType to parquetReader, we must pass StringType to it; when we read out data, we convert data from String to Decimal, everything is ok. for log reader, since our rewriteRecordwithNewSchema function support rewrite directly， so we no need this parameter **eg: current column type is StringType, now we changed it to decimalType,** we can pass decimalType to rewriteRecordwithNewSchema directly, everythings is ok. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
