org.apache.drill.exec.planner.index.IndexStatistics Maven / Gradle / Ivy

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/*
 * 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.drill.exec.planner.index;

import org.apache.calcite.rel.RelCollation;
import org.apache.calcite.rel.RelDistribution;


import java.util.List;

public interface IndexStatistics {
    /** Returns the approximate number of rows in the table. */
    double getRowCount();

    /** Returns the collections of columns on which this table is sorted. */
    List getCollations();

    /** Returns the distribution of the data in query result table. */
    RelDistribution getDistribution();

}