/*
* 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.eigenbase.relopt;
import java.util.BitSet;
import java.util.List;
import org.eigenbase.rel.RelNode;
import org.eigenbase.util.Pair;
import net.hydromatic.optiq.config.OptiqConnectionConfig;
import net.hydromatic.optiq.jdbc.OptiqSchema;
import net.hydromatic.optiq.materialize.Lattice;
import net.hydromatic.optiq.materialize.MaterializationService;
/**
* Use of a lattice by the query optimizer.
*/
public class RelOptLattice {
public final Lattice lattice;
public final RelOptTable starRelOptTable;
public RelOptLattice(Lattice lattice, RelOptTable starRelOptTable) {
this.lattice = lattice;
this.starRelOptTable = starRelOptTable;
}
public RelOptTable rootTable() {
return lattice.nodes.get(0).scan.getTable();
}
/** Rewrites a relational expression to use a lattice.
*
* <p>Returns null if a rewrite is not possible.
*
* @param node Relational expression
* @return Rewritten query
*/
public RelNode rewrite(RelNode node) {
return RelOptMaterialization.tryUseStar(node, starRelOptTable);
}
/** Retrieves a materialized table that will satisfy an aggregate query on
* the star table.
*
* <p>The current implementation creates a materialization and populates it,
* provided that {@link Lattice#auto} is true.
*
* <p>Future implementations might return materializations at a different
* level of aggregation, from which the desired result can be obtained by
* rolling up.
*
* @param planner Current planner
* @param groupSet Grouping key
* @param measureList Calls to aggregate functions
* @return Materialized table
*/
public
Pair<OptiqSchema.TableEntry, MaterializationService.TileKey> getAggregate(
RelOptPlanner planner, BitSet groupSet,
List<Lattice.Measure> measureList) {
final OptiqConnectionConfig config =
planner.getContext().unwrap(OptiqConnectionConfig.class);
if (config == null) {
return null;
}
final MaterializationService service = MaterializationService.instance();
boolean create = lattice.auto && config.createMaterializations();
final OptiqSchema schema = starRelOptTable.unwrap(OptiqSchema.class);
return service.defineTile(lattice, groupSet, measureList, schema, create);
}
}
// End RelOptLattice.java