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From manishgupta88 <...@git.apache.org>
Subject [GitHub] incubator-carbondata pull request #676: [CARBONDATA-797] Data loss for BigIn...
Date Mon, 20 Mar 2017 11:46:47 GMT
GitHub user manishgupta88 opened a pull request:

    https://github.com/apache/incubator-carbondata/pull/676

    [CARBONDATA-797] Data loss for BigInt datatype if data contains long max and min values

    When data contains long max and min values for a measure column with bigInt datatype,
the delta compression selected is DATA_BYTE which is incorrect. For selecting the delta compression
min value is decremented from max value and here the min value is negative, so it performs
addition operation and goes out of long range. When a long value goes out of range it starts
again from the long max negative value which results in wrong compression selection.
    
    This leads to data loss and incorrect query results.

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/manishgupta88/incubator-carbondata bigint_data_loss

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/incubator-carbondata/pull/676.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #676
    
----
commit 4f915d102a5f6186aed5a74cfe23a0a81ea62aee
Author: manishgupta88 <tomanishgupta18@gmail.com>
Date:   2017-03-20T11:43:02Z

    When data contains long max and min values for a measure column with bigInt datatype,
the delta compression selected is DATA_BYTE which is incorrect. For selecting the delta compression
min value is decremented from max value and here the min value is negative, so it performs
addition operation and goes out of long range. When a long value goes out of range it starts
again from the long max negative value which results in wrong compression selection.
    This leads to data loss and incorrect query results.

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