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From James Taylor <jamestay...@apache.org>
Subject Re: select Dynamic column Name
Date Thu, 27 Aug 2015 16:30:06 GMT
Hi Satya,
Since querying directly into the SYSTEM.CATALOG is not a supported API, you
might be affected when trying to upgrade to new versions of Phoenix when
we've made changes to the SYSTEM.CATALOG schema.For example, the
SYSTEM.CATALOG may have columns added and removed. Or we might create new
kind of linking rules (which your queries might pick up accidentally). Or
we might take what's one table and turn it into many: one with tables, one
with indexes and another with column definitions (an extreme example, but
you get the idea).

Thanks,
James


On Thu, Aug 27, 2015 at 9:22 AM, Ns G <nsgnsg84@gmail.com> wrote:

> Hi James,
>
> Would you mind if you can elaborate more what you mean by underlying
> schema changes?
>
> I am asking this because we are having a service which fetches columns
> from system catalog. If you can tell how It will affect then I shall
> fallback jdbc metadataapi.
>
> Thanks,
> Satya
> On 27-Aug-2015 8:26 pm, "James Taylor" <jamestaylor@apache.org> wrote:
>
>> Use these standard JDBC APIs:
>> http://docs.oracle.com/javase/7/docs/api/java/sql/DatabaseMetaData.html
>>
>> Querying directly against the SYSTEM.CATALOG is not recommended as
>> underlying schema changes may impact you.
>>
>> Thanks,
>> James
>>
>> On Thursday, August 27, 2015, Ns G <nsgnsg84@gmail.com> wrote:
>>
>>> Hi James,
>>>
>>> I think we can get the dynamic column names from SYSTEM.CATALOG table.
>>> Using as co-related sub query we can use  in select statement and fetch
>>> details. Isn't this an option to consider? Do you see anything wrong with
>>> this approach?
>>>
>>> Thanks,
>>> Satya
>>> On 27-Aug-2015 7:28 pm, "Manjee, Sunile" <Sunile.Manjee@teradata.com>
>>> wrote:
>>>
>>>> James,
>>>> Where can I find info on "JDBC Metadata APIs for each view entity"
>>>>
>>>> From: James Taylor <jamestaylor@apache.org>
>>>> Reply-To: "user@phoenix.apache.org" <user@phoenix.apache.org>
>>>> Date: Monday, August 24, 2015 at 3:04 PM
>>>> To: user <user@phoenix.apache.org>
>>>> Subject: Re: select Dynamic column Name
>>>>
>>>> JDBC Metadata APIs for each view entity
>>>>
>>>

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