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https://issues.apache.org/jira/browse/PHOENIX-2417?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15103511#comment-15103511
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ASF GitHub Bot commented on PHOENIX-2417:
-----------------------------------------

Github user JamesRTaylor commented on a diff in the pull request:

    https://github.com/apache/phoenix/pull/147#discussion_r49939246
  
    --- Diff: 
phoenix-core/src/main/java/org/apache/phoenix/util/CodecUtils.java ---
    @@ -0,0 +1,104 @@
    +/*
    + * 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 org.apache.phoenix.util;
    +
    +import java.io.ByteArrayInputStream;
    +import java.io.ByteArrayOutputStream;
    +import java.io.DataInput;
    +import java.io.DataInputStream;
    +import java.io.DataOutput;
    +import java.io.DataOutputStream;
    +import java.io.EOFException;
    +import java.io.IOException;
    +import java.util.List;
    +
    +import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
    +
    +import com.google.common.collect.Lists;
    +
    +public class CodecUtils {
    --- End diff --
    
    Rename to PrefixByteCodec


> Compress memory used by row key byte[] of guideposts
> ----------------------------------------------------
>
>                 Key: PHOENIX-2417
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-2417
>             Project: Phoenix
>          Issue Type: Sub-task
>            Reporter: James Taylor
>            Assignee: Ankit Singhal
>             Fix For: 4.7.0
>
>         Attachments: PHOENIX-2417.patch, PHOENIX-2417_encoder.diff, 
> PHOENIX-2417_v2_wip.patch
>
>
> We've found that smaller guideposts are better in terms of minimizing any 
> increase in latency for point scans. However, this increases the amount of 
> memory significantly when caching the guideposts on the client. Guidepost are 
> equidistant row keys in the form of raw byte[] which are likely to have a 
> large percentage of their leading bytes in common (as they're stored in 
> sorted order. We should use a simple compression technique to mitigate this. 
> I noticed that Apache Parquet has a run length encoding - perhaps we can use 
> that.



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