com.hazelcast.org.apache.calcite.plan.RelOptLattice Maven / Gradle / Ivy
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* 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,
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package com.hazelcast.org.apache.calcite.plan;
import com.hazelcast.org.apache.calcite.config.CalciteConnectionConfig;
import com.hazelcast.org.apache.calcite.jdbc.CalciteSchema;
import com.hazelcast.org.apache.calcite.materialize.Lattice;
import com.hazelcast.org.apache.calcite.materialize.MaterializationService;
import com.hazelcast.org.apache.calcite.materialize.TileKey;
import com.hazelcast.org.apache.calcite.rel.RelNode;
import com.hazelcast.org.apache.calcite.util.ImmutableBitSet;
import com.hazelcast.org.apache.calcite.util.Pair;
import com.hazelcast.org.checkerframework.checker.nullness.qual.Nullable;
import java.util.List;
/**
* 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.rootNode.relOptTable();
}
/** Rewrites a relational expression to use a lattice.
*
* Returns null if a rewrite is not possible.
*
* @param node Relational expression
* @return Rewritten query
*/
public @Nullable RelNode rewrite(RelNode node) {
return RelOptMaterialization.tryUseStar(node, starRelOptTable);
}
/** Retrieves a materialized table that will satisfy an aggregate query on
* the star table.
*
*
The current implementation creates a materialization and populates it,
* provided that {@link Lattice#auto} is true.
*
*
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 @Nullable Pair getAggregate(
RelOptPlanner planner, ImmutableBitSet groupSet,
List measureList) {
final CalciteConnectionConfig config =
planner.getContext().unwrap(CalciteConnectionConfig.class);
if (config == null) {
return null;
}
final MaterializationService service = MaterializationService.instance();
boolean create = lattice.auto && config.createMaterializations();
final CalciteSchema schema = starRelOptTable.unwrap(CalciteSchema.class);
assert schema != null : "Can't get CalciteSchema from " + starRelOptTable;
return service.defineTile(lattice, groupSet, measureList, schema, create,
false);
}
}