org.teiid.UserDefinedAggregate Maven / Gradle / Ivy
/*
* Copyright Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags and
* the COPYRIGHT.txt file distributed with this work.
*
* 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 org.teiid;
/**
* Interface to be implemented by a user defined aggregate function.
* @param
*/
public interface UserDefinedAggregate {
/**
* Called when state from the current partition can be forgotten
*/
void reset();
/**
* Called to get the current value. May be called multiple times in the same
* partition for windowed aggregates.
* @param commandContext
* @return
*/
T getResult(CommandContext commandContext);
}