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https://issues.apache.org/jira/browse/HIVE-23829?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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David Mollitor resolved HIVE-23829.
-----------------------------------
Fix Version/s: 4.0.0
Resolution: Fixed
Pushed to master. Thanks!
> Compute Stats Incorrect for Binary Columns
> ------------------------------------------
>
> Key: HIVE-23829
> URL: https://issues.apache.org/jira/browse/HIVE-23829
> Project: Hive
> Issue Type: Bug
> Reporter: David Mollitor
> Assignee: David Mollitor
> Priority: Minor
> Labels: pull-request-available
> Fix For: 4.0.0
>
> Time Spent: 1h 50m
> Remaining Estimate: 0h
>
> I came across an issue when working on [HIVE-22674].
> The SerDe used for processing binary data tries to auto-detect if the data is
> in Base-64. It uses
> {{org.apache.commons.codec.binary.Base64#isArrayByteBase64}} which has two
> issues:
> # It's slow since it will check if the array is compatible,... and then
> process the data (examines the array twice)
> # More importantly, this method _Tests a given byte array to see if it
> contains only valid characters within the Base64 alphabet. Currently the
> method treats whitespace as valid._
> https://commons.apache.org/proper/commons-codec/apidocs/org/apache/commons/codec/binary/Base64.html#isArrayByteBase64-byte:A-
> The
> [qtest|https://github.com/apache/hive/blob/f98e136bdd5642e3de10d2fd1a4c14d1d6762113/ql/src/test/queries/clientpositive/compute_stats_binary.q]
> for this feature uses full sentences (which includes spaces)
> [here|https://github.com/apache/hive/blob/f98e136bdd5642e3de10d2fd1a4c14d1d6762113/data/files/binary.txt]
> and therefore it thinks this data is Base-64 and returns an incorrect
> estimation for size.
> This should really not auto-detect Base64 data and instead it should be
> enabled with a table property.
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