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https://issues.apache.org/jira/browse/DRILL-5517?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16068506#comment-16068506
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ASF GitHub Bot commented on DRILL-5517:
---------------------------------------

Github user amansinha100 commented on a diff in the pull request:

    https://github.com/apache/drill/pull/840#discussion_r124835442
  
    --- Diff: 
exec/vector/src/main/java/org/apache/drill/exec/vector/VectorUtils.java ---
    @@ -0,0 +1,56 @@
    +/*
    + * 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.drill.exec.vector;
    +
    +public class VectorUtils {
    +
    +  /**
    +   * Vectors cannot be any larger than the Netty memory allocation
    +   * block size.
    +   */
    +
    +  private static final int ABSOLUTE_MAX_SIZE = 16 * 1024 * 1024;
    +  private static final int ABSOLUTE_MIN_SIZE = 16 * 1024;
    --- End diff --
    
    It wasn't clear why the absolute_min_size is 16K .. that's not related to 
Netty I presume.  Couldn't it be much smaller ?


> Provide size-aware set operations in value vectors
> --------------------------------------------------
>
>                 Key: DRILL-5517
>                 URL: https://issues.apache.org/jira/browse/DRILL-5517
>             Project: Apache Drill
>          Issue Type: Improvement
>    Affects Versions: 1.11.0
>            Reporter: Paul Rogers
>            Assignee: Paul Rogers
>              Labels: ready-to-commit
>             Fix For: 1.11.0
>
>
> DRILL-5211 describes a memory fragmentation issue in Drill. The resolution is 
> to limit vector sizes to 16 MB (the size of Netty memory allocation "slabs.") 
> Effort starts by providing "size-aware" set operations in value vectors which:
> * Operate as {{setSafe()}} while vectors are below 16 MB.
> * Throw a new, specific exception ({{VectorOverflowException}}) if setting 
> the value (and growing the vector) would exceed the vector limit.
> The methods in value vectors then become the foundation on which we can 
> construct size-aware record batch "writers."



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