matriv commented on a change in pull request #18582: URL: https://github.com/apache/flink/pull/18582#discussion_r800519982
########## File path: flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/casting/TimestampToTimestampCastRule.java ########## @@ -0,0 +1,98 @@ +/* + * 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.planner.functions.casting; + +import org.apache.flink.table.data.TimestampData; +import org.apache.flink.table.planner.codegen.calls.BuiltInMethods; +import org.apache.flink.table.types.logical.LogicalType; +import org.apache.flink.table.types.logical.LogicalTypeRoot; +import org.apache.flink.table.types.logical.TimestampKind; +import org.apache.flink.table.types.logical.TimestampType; +import org.apache.flink.table.types.logical.utils.LogicalTypeChecks; + +import static org.apache.flink.table.planner.functions.casting.CastRuleUtils.staticCall; + +/** + * {@link LogicalTypeRoot#TIMESTAMP_WITHOUT_TIME_ZONE}/{@link + * LogicalTypeRoot#TIMESTAMP_WITH_LOCAL_TIME_ZONE} to {@link + * LogicalTypeRoot#TIMESTAMP_WITHOUT_TIME_ZONE}/{@link LogicalTypeRoot#TIMESTAMP_WITHOUT_TIME_ZONE} + * cast rule. Check and adjust if there is the precision changes. + */ +class TimestampToTimestampCastRule + extends AbstractExpressionCodeGeneratorCastRule<TimestampData, TimestampData> { + + static final TimestampToTimestampCastRule INSTANCE = new TimestampToTimestampCastRule(); + + private TimestampToTimestampCastRule() { + super( + CastRulePredicate.builder() + .input(LogicalTypeRoot.TIMESTAMP_WITHOUT_TIME_ZONE) + .input(LogicalTypeRoot.TIMESTAMP_WITH_LOCAL_TIME_ZONE) + .target(LogicalTypeRoot.TIMESTAMP_WITHOUT_TIME_ZONE) + .target(LogicalTypeRoot.TIMESTAMP_WITH_LOCAL_TIME_ZONE) + .build()); + } + + @Override + public String generateExpression( + CodeGeneratorCastRule.Context context, + String inputTerm, + LogicalType inputLogicalType, + LogicalType targetLogicalType) { + final int inputPrecision = LogicalTypeChecks.getPrecision(inputLogicalType); + int targetPrecision = LogicalTypeChecks.getPrecision(targetLogicalType); + + if (inputLogicalType.is(LogicalTypeRoot.TIMESTAMP_WITHOUT_TIME_ZONE) + && targetLogicalType.is(LogicalTypeRoot.TIMESTAMP_WITHOUT_TIME_ZONE)) { + final TimestampKind inputTimestampKind = ((TimestampType) inputLogicalType).getKind(); + final TimestampKind targetTimestampKind = ((TimestampType) targetLogicalType).getKind(); + if (inputTimestampKind == TimestampKind.ROWTIME + || inputTimestampKind == TimestampKind.PROCTIME + || targetTimestampKind == TimestampKind.ROWTIME + || targetTimestampKind == TimestampKind.PROCTIME) { + targetPrecision = 3; Review comment: we want `targetPrecision = 3` because everywhere in the code for performance reasons we treat those timestamps always as long, which means only milliseconds precision. If we allow more precision, then we can still make comparisons, etc. but any code that uses those timestamps must be checked and potentially, we would need to push down the pipeline the chosen precision, so the code needs how to process that if for example needs to print them like strings. -- 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]
