com.hazelcast.sql.impl.schema.TableStatistics Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2021, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.sql.impl.schema;
/**
* Statistics for the table. Must not invoke any distributed operations.
*/
public interface TableStatistics {
/**
* Gets the estimated number of rows in the table that is used during planning for cost calculation.
* Must return non-negative number. If the underlying table cannot estimate the number of rows, some
* constant might be provided.
*
* @return Estimated number of rows in the table. Never negative.
*/
long getRowCount();
}