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From "kulkarni.swarnim@gmail.com" <kulkarni.swar...@gmail.com>
Subject Re: hbase column without prefix
Date Thu, 23 Jul 2015 15:21:37 GMT
So let me ask you this. If we did not have the support for pulling data via
prefixes, there would be two options for us to pull this data. One, wither
we provide just the column family name like "fam:" and let hive pull
everything under that column family and stuff it in a map with key being
the column name. Or, the other option would be to provide the column names
individually. In either case, the column prefixes would end up in the hive
column name. My intend behind adding this support was to have a shortcut
way which was an extension of the existing support to pull all columns by
providing a "family_name:" to pulling just the columns that start with
given prefix. Everything else should stay same and consistent. That said, I
am ok with adding a flag to hide the prefix in the column name, IMO it
would be confusing for someone to understand why in this particular case
the prefix needs to be hidden vs not in any other case.

Does that make sense?

On Thu, Jul 23, 2015 at 9:46 AM, Wojciech Indyk <wojciechindyk@gmail.com>
wrote:

> Hello!
>
> Yes, but if I define a map prefix "tag_" I don't want to receive the
> prefix for each element of the map. I know what the prefix for the map
> is. It is hard to join such data with another structures which doesn't
> have prefixes. All in all it's easier to integrate data without
> prefixes. IMO Prefixes are artificial structure (like 'super-column')
> to optimize queries and be able to store a map in hbase. That's why i
> want to cut prefixes.
>
> What do you think about it? Does it make sense for you? Even if it's
> not a bug it would be nice to have option to hide prefixes in keys of
> map.
>
> Kindly regards
> Wojciech Indyk
>
>
> 2015-07-23 16:32 GMT+02:00 kulkarni.swarnim@gmail.com
> <kulkarni.swarnim@gmail.com>:
> > Hey,
> >
> > Just so that I understand your issue better, why do you think it should
> be
> >
> > key: one, value: 0.5
> > key: two: value: 0.5
> >
> > instead of
> >
> > key: tag_one, value: 0.5
> > key: tag_two, value: 0.5
> >
> > when you know that the prefixes for your columns are tag_. Hive won't
> > really do anything but simply pull all the columns that start with the
> > given prefix and add them to the key for your map which is exactly what
> you
> > are seeing here.
> >
> >
> > On Wed, Jul 22, 2015 at 10:03 AM, Wojciech Indyk <
> wojciechindyk@gmail.com>
> > wrote:
> >
> >> Hi!
> >> I've created an issue https://issues.apache.org/jira/browse/HIVE-11329
> >> and need an advice is it a bug or should it be a new feature, e.g. a
> >> flag to enable somewhere in a table definition?
> >> I am eager to create a patch, however I need some help with design a
> >> work to do (e.g. which modules affect this thing).
> >>
> >> Kindly regards
> >> Wojciech Indyk
> >>
> >
> >
> >
> > --
> > Swarnim
>



-- 
Swarnim

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