com.hazelcast.org.apache.calcite.adapter.enumerable.WinAggImplementor 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 com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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;
/**
* Implements a windowed aggregate function by generating expressions to
* initialize, add to, and get a result from, an accumulator.
* Windowed aggregate is more powerful than regular aggregate since it can
* access rows in the current partition by row indices.
* Regular aggregate can be used to implement windowed aggregate.
* This interface does not define new methods: window-specific
* sub-interfaces are passed when implementing window aggregate.
*
* @see com.hazelcast.org.apache.calcite.adapter.enumerable.StrictWinAggImplementor
* @see com.hazelcast.org.apache.calcite.adapter.enumerable.RexImpTable.FirstLastValueImplementor
* @see com.hazelcast.org.apache.calcite.adapter.enumerable.RexImpTable.RankImplementor
* @see com.hazelcast.org.apache.calcite.adapter.enumerable.RexImpTable.RowNumberImplementor
*/
public interface WinAggImplementor extends AggImplementor {
/**
* Allows to access rows in window partition relative to first/last and
* current row.
*/
enum SeekType {
/**
* Start of window.
* @see WinAggFrameContext#startIndex()
*/
START,
/**
* Row position in the frame.
* @see WinAggFrameContext#index()
*/
SET,
/**
* The index of row that is aggregated.
* Valid only in {@link WinAggAddContext}.
* @see WinAggAddContext#currentPosition()
*/
AGG_INDEX,
/**
* End of window.
* @see WinAggFrameContext#endIndex()
*/
END
}
boolean needCacheWhenFrameIntact();
}