com.hazelcast.org.apache.calcite.adapter.enumerable.WinAggFrameContext Maven / Gradle / Ivy
/*
* 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 com.hazelcast.org.apache.calcite.adapter.enumerable;
import com.hazelcast.org.apache.calcite.linq4j.tree.Expression;
/**
* Provides information on the current window.
*
* All the indexes are ready to be used in
* {@link WinAggResultContext#arguments(com.hazelcast.org.apache.calcite.linq4j.tree.Expression)},
* {@link WinAggFrameResultContext#rowTranslator(com.hazelcast.org.apache.calcite.linq4j.tree.Expression)}
* and similar methods.
*/
public interface WinAggFrameContext {
/**
* Returns the index of the current row in the partition.
* In other words, it is close to ~ROWS BETWEEN CURRENT ROW.
* Note to use {@link #startIndex()} when you need zero-based row position.
* @return the index of the very first row in partition
*/
Expression index();
/**
* Returns the index of the very first row in partition.
* @return index of the very first row in partition
*/
Expression startIndex();
/**
* Returns the index of the very last row in partition.
* @return index of the very last row in partition
*/
Expression endIndex();
/**
* Returns the boolean expression that tells if the partition has rows.
* The partition might lack rows in cases like ROWS BETWEEN 1000 PRECEDING
* AND 900 PRECEDING.
* @return boolean expression that tells if the partition has rows
*/
Expression hasRows();
/**
* Returns the number of rows in the current frame (subject to framing
* clause).
* @return number of rows in the current partition or 0 if the partition
* is empty
*/
Expression getFrameRowCount();
/**
* Returns the number of rows in the current partition (as determined by
* PARTITION BY clause).
* @return number of rows in the current partition or 0 if the partition
* is empty
*/
Expression getPartitionRowCount();
}