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From "Justin Leet (JIRA)" <>
Subject [jira] [Created] (HIVE-7898) HCatStorer should ignore namespaces generated by Pig
Date Thu, 28 Aug 2014 04:29:58 GMT
Justin Leet created HIVE-7898:

             Summary: HCatStorer should ignore namespaces generated by Pig
                 Key: HIVE-7898
             Project: Hive
          Issue Type: Improvement
          Components: HCatalog
    Affects Versions: 0.13.1
            Reporter: Justin Leet
            Assignee: Justin Leet
            Priority: Minor

Currently, Pig aliases must exactly match the names of HCat columns for HCatStorer to be successful.
 However, several Pig operations prepend a namespace to the alias in order to differentiate
fields (e.g. after a group with field b, you might have A::b).  In this case, even if the
fields are in the right order and the alias without namespace matches, the store will fail
because it tries to match the long form of the alias, despite the namespace being extraneous
information in this case.   Note that multiple aliases can be applied (e.g. A::B::C::d).

A workaround is possible by doing a 
FOREACH relation GENERATE field1 AS field1, field2 AS field2, etc.  
This quickly becomes tedious and bloated for tables with many fields.

Changing this would normally require care around columns named, for example, `A::b` as has
been introduced in Hive 13.  However, a different function call only validates Pig aliases
if they follow the old rules for Hive columns.  As such, a direct change (rather than attempting
to match either the namespace::alias or just alias) maintains compatibility for now.

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