All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.facebook.presto.jdbc.internal.spi.function.WindowFunction Maven / Gradle / Ivy

There is a newer version: 0.289
Show newest version
/*
 * 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.facebook.presto.jdbc.internal.spi.function;

import com.facebook.presto.jdbc.internal.common.block.BlockBuilder;

public interface WindowFunction
{
    /**
     * Reset state for a new partition (including the first one).
     *
     * @param windowIndex the window index which contains sorted values for the partition
     */
    void reset(WindowIndex windowIndex);

    /**
     * Process a row by outputting the result of the window function.
     * 

* This method provides information about the ordering peer group. A peer group is all * of the rows that are peers within the specified ordering. Rows are peers if they * compare equal to each other using the specified ordering expression. The ordering * of rows within a peer group is undefined (otherwise they would not be peers). * * @param output the {@link BlockBuilder} to use for writing the output row * @param peerGroupStart the position of the first row in the peer group * @param peerGroupEnd the position of the last row in the peer group * @param frameStart the position of the first row in the window frame * @param frameEnd the position of the last row in the window frame */ void processRow(BlockBuilder output, int peerGroupStart, int peerGroupEnd, int frameStart, int frameEnd); }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy