kasakrisz commented on code in PR #4079: URL: https://github.com/apache/hive/pull/4079#discussion_r1133604073
########## ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/views/HivePushdownSnapshotFilterRule.java: ########## @@ -0,0 +1,156 @@ +/* + * 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.hadoop.hive.ql.optimizer.calcite.rules.views; + +import org.apache.calcite.plan.RelOptRule; +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelOptTable; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.metadata.RelMetadataQuery; +import org.apache.calcite.rel.type.RelDataTypeField; +import org.apache.calcite.rex.RexBuilder; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexInputRef; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexTableInputRef; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.apache.hadoop.hive.ql.metadata.VirtualColumn; +import org.apache.hadoop.hive.ql.optimizer.calcite.HiveRelFactories; +import org.apache.hadoop.hive.ql.optimizer.calcite.RelOptHiveTable; +import org.apache.hadoop.hive.ql.optimizer.calcite.reloperators.HiveFilter; + +import java.util.Set; + +/** + * Calcite rule to push down predicates contains {@link VirtualColumn#SNAPSHOT_ID} reference to TableScan. + * <p> + * This rule traverse the logical expression in {@link HiveFilter} operators and search for + * predicates like + * <p> + * <code> + * snapshotId <= 12345677899 + * </code> + * <p> + * The literal is set in the {@link RelOptHiveTable#getHiveTableMD()} object wrapped by + * {@link org.apache.hadoop.hive.ql.optimizer.calcite.reloperators.HiveTableScan} + * and the original predicate in the {@link HiveFilter} is replaced with literal true. + */ +public class HivePushdownSnapshotFilterRule extends RelRule<HivePushdownSnapshotFilterRule.Config> { + + public static final RelOptRule INSTANCE = + RelRule.Config.EMPTY.as(HivePushdownSnapshotFilterRule.Config.class) + .withRelBuilderFactory(HiveRelFactories.HIVE_BUILDER) + .withOperandSupplier(operandBuilder -> operandBuilder.operand(HiveFilter.class).anyInputs()) + .withDescription("HivePushdownSnapshotFilterRule") + .toRule(); + + public interface Config extends RelRule.Config { + @Override + default HivePushdownSnapshotFilterRule toRule() { + return new HivePushdownSnapshotFilterRule(this); + } + } + + private HivePushdownSnapshotFilterRule(Config config) { + super(config); + } + + @Override + public void onMatch(RelOptRuleCall call) { + HiveFilter filter = call.rel(0); Review Comment: Yes. In order to identify snapshotId references all column references should be checked in the predicate. To do it the predicate expression has to be traversed. `SnapshotIdShuttle` does this traversal and it also sets the snapshotId in the source TS. Please let me know if you have a better/faster solution to check whether a predicate expression has snapshotId reference. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
