com.hazelcast.org.apache.calcite.rel.rules.CalcSplitRule Maven / Gradle / Ivy
/*
* 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 com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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 com.hazelcast.org.apache.calcite.rel.rules;
import com.hazelcast.org.apache.calcite.plan.RelOptRule;
import com.hazelcast.org.apache.calcite.plan.RelOptRuleCall;
import com.hazelcast.org.apache.calcite.rel.core.Calc;
import com.hazelcast.org.apache.calcite.rel.core.Filter;
import com.hazelcast.org.apache.calcite.rel.core.RelFactories;
import com.hazelcast.org.apache.calcite.rex.RexNode;
import com.hazelcast.org.apache.calcite.tools.RelBuilder;
import com.hazelcast.org.apache.calcite.tools.RelBuilderFactory;
import com.hazelcast.org.apache.calcite.util.Pair;
import com.hazelcast.com.google.com.hazelcast.com.on.collect.ImmutableList;
/**
* Planner rule that converts a {@link Calc}
* to a {@link com.hazelcast.org.apache.calcite.rel.core.Project}
* and {@link Filter}.
*
* Not enabled by default, as it works against the usual flow, which is to
* convert {@code Project} and {@code Filter} to {@code Calc}. But useful for
* specific tasks, such as optimizing before calling an
* {@link com.hazelcast.org.apache.calcite.interpreter.Interpreter}.
*/
public class CalcSplitRule extends RelOptRule implements TransformationRule {
public static final CalcSplitRule INSTANCE =
new CalcSplitRule(RelFactories.LOGICAL_BUILDER);
/**
* Creates a CalcSplitRule.
*
* @param relBuilderFactory Builder for relational expressions
*/
public CalcSplitRule(RelBuilderFactory relBuilderFactory) {
super(operand(Calc.class, any()), relBuilderFactory, null);
}
@Override public void onMatch(RelOptRuleCall call) {
final Calc calc = call.rel(0);
final Pair, ImmutableList> projectFilter =
calc.getProgram().split();
final RelBuilder relBuilder = call.builder();
relBuilder.push(calc.getInput());
relBuilder.filter(projectFilter.right);
relBuilder.project(projectFilter.left, calc.getRowType().getFieldNames());
call.transformTo(relBuilder.build());
}
}