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From Kasper Sørensen <i.am.kasper.soren...@gmail.com>
Subject Re: [DISCUSS] JSON DataContext and a 'Schema inference' aspect in the 'core' module
Date Wed, 09 Jul 2014 17:23:57 GMT
I'll go ahead then, noone seems to have an issue with this :-)


2014-07-08 18:29 GMT+02:00 Ankit Kumar <ak.ankitkumar@gmail.com>:

> +1
>
> Ankit
>
> > On 08 Jul 2014, at 15:09, Kasper Sørensen <
> i.am.kasper.sorensen@gmail.com> wrote:
> >
> > Well almost. It would be a Map<String,Object>, since the value-type is
> > unknown. For instance, if the document had nested objects or arrays, or
> > even a number-value, it would not always be a string value. The metadata
> > would say that the column type is ColumnType.MAP
> >
> >
> > 2014-07-08 12:56 GMT+02:00 Ankit Kumar <ak.ankitkumar@gmail.com>:
> >
> >> Hi Kasper,
> >>
> >> Quick question - Will the map based interpretation of the JSON be a
> >> Map<String,String> type and would we get this automatically in that type
> >> when reading the column from the row.
> >>
> >> If that's the idea then I would vote for it [+1] as we can already
> benefit
> >> from this.
> >>
> >> If I interpret it incorrect then do please enlighten me.
> >>
> >> Regards
> >> Ankit
> >>
> >>
> >> On Thu, Jul 3, 2014 at 12:26 PM, Kasper Sørensen <
> >> i.am.kasper.sorensen@gmail.com> wrote:
> >>
> >>> Hi guys,
> >>>
> >>> Maybe you saw that I posted a review request [1] yesterday for
> >> METAMODEL-38
> >>> (a JSON based module for MetaModel).
> >>>
> >>> I was building this JSON module and trying to do it in a way where the
> >> user
> >>> could configure how the logical schema would look like. In some cases
> you
> >>> would want MetaModel to infer the schema based on a sample of documents
> >> in
> >>> the source, and in other cases you might want MetaModel to just treat
> the
> >>> source as a 1-column table with a MAP data type. There's probably also
> >>> other strategies.
> >>>
> >>> That part I felt was also very relevant for many other "schemaless"
> >>> datastores, such as MongoDB, CouchDB, HBase etc. So I put there
> >> interfaces
> >>> and a few standard implementations of it into the core module, and
> >> applied
> >>> it to the JSON module. If this idea is accepted, I would like to also
> add
> >>> it to MongoDB and CouchDB modules (those are a natural fit) and maybe
> >> also
> >>> HBase (slight more advanced because of the column-family concept).
> >>>
> >>> I think it makes sense to open a DISCUSS thread about this approach,
> >> since
> >>> Schema Inference is in itself a very nice distinguishing feature I
> think.
> >>> I'd like to invite anyone to share their ideas here, so that this is
> >> maybe
> >>> a place where we can make MetaModel shine.
> >>>
> >>> Cheers,
> >>> Kasper
> >>>
> >>> [1] https://reviews.apache.org/r/23228/
> >>
>

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