hazelcast-master/hazelcast-sql/src/main/java/com/hazelcast/sql/impl/schema/TableStatistics.java
/*
 * Copyright 2023 Hazelcast Inc.
 *
 * Licensed under the Hazelcast Community License (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://hazelcast.com/hazelcast-community-license
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES 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();
}
