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From Lefty Leverenz <leftylever...@gmail.com>
Subject Re: Hive Macros roadmap
Date Mon, 14 Sep 2015 05:53:27 GMT
HIVE-2655 <https://issues.apache.org/jira/browse/HIVE-2655> added macros in
release 0.12.0, so I've added a TODOC12 label and doc note to it.

Thank you Elliot for drawing this to our attention.

-- Lefty


On Fri, Sep 11, 2015 at 3:41 PM, Edward Capriolo <edlinuxguru@gmail.com>
wrote:

> Macro's are in and tested. No one will remove them. The unit tests ensure
> they keep working.
>
> On Fri, Sep 11, 2015 at 3:38 PM, Elliot West <teabot@gmail.com> wrote:
>
>> Hi,
>>
>> I noticed some time ago the Hive Macro feature. To me at least this
>> seemed like an excellent addition to HQL, allowing the user to encapsulate
>> complex column logic as an independent HQL, reusable macro while avoiding
>> the complexities of Java UDFs. However, few people seem to be aware of them
>> or use them. If you are unfamiliar with macros they look like this:
>>
>> hive> create temporary macro MYSIGMOID(x DOUBLE)
>>     > 2.0 / (1.0 + exp(-x));
>> OK
>>
>> hive> select MYSIGMOID(1.0) from dual;
>> OK
>>
>> 1.4621171572600098
>>
>>
>> As far as I can tell, they are no longer documented on the Hive wiki.
>> There is a tiny reference to them in the O'Reilly 'Programming Hive' book
>> (page 185). Can anyone advise me on the following:
>>
>>    - Are there are plans to keep or remove this functionality?
>>    - Are there are plans to document this functionality?
>>    - Aside from limitations of HQL are there compelling reasons not to
>>    use macros?
>>
>> Thanks - Elliot.
>>
>>
>

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