com.hazelcast.org.apache.calcite.rel.rules.ProjectTableScanRule Maven / Gradle / Ivy
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* 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.
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package com.hazelcast.org.apache.calcite.rel.rules;
import com.hazelcast.org.apache.calcite.adapter.enumerable.EnumerableInterpreter;
import com.hazelcast.org.apache.calcite.interpreter.Bindables;
import com.hazelcast.org.apache.calcite.plan.RelOptRule;
import com.hazelcast.org.apache.calcite.plan.RelOptRuleCall;
import com.hazelcast.org.apache.calcite.plan.RelOptRuleOperand;
import com.hazelcast.org.apache.calcite.plan.RelOptTable;
import com.hazelcast.org.apache.calcite.rel.core.Project;
import com.hazelcast.org.apache.calcite.rel.core.RelFactories;
import com.hazelcast.org.apache.calcite.rel.core.TableScan;
import com.hazelcast.org.apache.calcite.rex.RexInputRef;
import com.hazelcast.org.apache.calcite.rex.RexNode;
import com.hazelcast.org.apache.calcite.rex.RexUtil;
import com.hazelcast.org.apache.calcite.rex.RexVisitorImpl;
import com.hazelcast.org.apache.calcite.schema.ProjectableFilterableTable;
import com.hazelcast.org.apache.calcite.tools.RelBuilderFactory;
import com.hazelcast.org.apache.calcite.util.mapping.Mapping;
import com.hazelcast.org.apache.calcite.util.mapping.Mappings;
import com.hazelcast.com.google.common.collect.ImmutableList;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
/**
* Planner rule that converts a {@link Project}
* on a {@link com.hazelcast.org.apache.calcite.rel.core.TableScan}
* of a {@link com.hazelcast.org.apache.calcite.schema.ProjectableFilterableTable}
* to a {@link com.hazelcast.org.apache.calcite.interpreter.Bindables.BindableTableScan}.
*
* The {@link #INTERPRETER} variant allows an intervening
* {@link com.hazelcast.org.apache.calcite.adapter.enumerable.EnumerableInterpreter}.
*
* @see FilterTableScanRule
*/
public abstract class ProjectTableScanRule extends RelOptRule {
@SuppressWarnings("Guava")
@Deprecated // to be removed before 2.0
public static final com.hazelcast.com.google.common.base.Predicate PREDICATE =
ProjectTableScanRule::test;
/** Rule that matches Project on TableScan. */
public static final ProjectTableScanRule INSTANCE =
new ProjectTableScanRule(
operand(Project.class,
operandJ(TableScan.class, null, ProjectTableScanRule::test,
none())),
RelFactories.LOGICAL_BUILDER,
"ProjectScanRule") {
@Override public void onMatch(RelOptRuleCall call) {
final Project project = call.rel(0);
final TableScan scan = call.rel(1);
apply(call, project, scan);
}
};
/** Rule that matches Project on EnumerableInterpreter on TableScan. */
public static final ProjectTableScanRule INTERPRETER =
new ProjectTableScanRule(
operand(Project.class,
operand(EnumerableInterpreter.class,
operandJ(TableScan.class, null, ProjectTableScanRule::test,
none()))),
RelFactories.LOGICAL_BUILDER,
"ProjectScanRule:interpreter") {
@Override public void onMatch(RelOptRuleCall call) {
final Project project = call.rel(0);
final TableScan scan = call.rel(2);
apply(call, project, scan);
}
};
//~ Constructors -----------------------------------------------------------
/** Creates a ProjectTableScanRule. */
public ProjectTableScanRule(RelOptRuleOperand operand,
RelBuilderFactory relBuilderFactory, String description) {
super(operand, relBuilderFactory, description);
}
//~ Methods ----------------------------------------------------------------
protected static boolean test(TableScan scan) {
// We can only push projects into a ProjectableFilterableTable.
final RelOptTable table = scan.getTable();
return table.unwrap(ProjectableFilterableTable.class) != null;
}
protected void apply(RelOptRuleCall call, Project project, TableScan scan) {
final RelOptTable table = scan.getTable();
assert table.unwrap(ProjectableFilterableTable.class) != null;
final List selectedColumns = new ArrayList<>();
project.getProjects().forEach(proj -> {
proj.accept(new RexVisitorImpl(true) {
public Void visitInputRef(RexInputRef inputRef) {
if (!selectedColumns.contains(inputRef.getIndex())) {
selectedColumns.add(inputRef.getIndex());
}
return null;
}
});
});
final List filtersPushDown;
final List projectsPushDown;
if (scan instanceof Bindables.BindableTableScan) {
final Bindables.BindableTableScan bindableScan =
(Bindables.BindableTableScan) scan;
filtersPushDown = bindableScan.filters;
projectsPushDown = selectedColumns.stream()
.map(col -> bindableScan.projects.get(col))
.collect(Collectors.toList());
} else {
filtersPushDown = ImmutableList.of();
projectsPushDown = selectedColumns;
}
Bindables.BindableTableScan newScan = Bindables.BindableTableScan.create(
scan.getCluster(), scan.getTable(), filtersPushDown, projectsPushDown);
Mapping mapping =
Mappings.target(selectedColumns, scan.getRowType().getFieldCount());
final List newProjectRexNodes =
ImmutableList.copyOf(RexUtil.apply(mapping, project.getProjects()));
if (RexUtil.isIdentity(newProjectRexNodes, newScan.getRowType())) {
call.transformTo(newScan);
} else {
call.transformTo(
call.builder()
.push(newScan)
.project(newProjectRexNodes)
.build());
}
}
}