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From Kristian Waagan <kristian.waa...@oracle.com>
Subject Re: limit on the number of columns
Date Fri, 25 May 2012 08:21:10 GMT
On 24.05.2012 23:33, Patrick Meyer wrote:
> That would be excellent! I think it would be a great feature to have in
> Derby.

Hi Patrick,

Can you say anything about how many columns would be needed to support 
these use-cases?
Are we talking about a few thousand, ten thousand, or even more columns?


> Patrick
> -----Original Message-----
> From: Rick Hillegas [mailto:rick.hillegas@oracle.com]
> Sent: Thursday, May 24, 2012 12:08 PM
> To: derby-user@db.apache.org
> Subject: Re: limit on the number of columns
> On 5/24/12 4:26 AM, Patrick Meyer wrote:
>> I am aware that Derby has a limit of 1,012 columns for each table, but
>> many users of my application (it is a program for statistical
>> analysis) have very large files that go well beyond this number of
>> columns. Does anyone know of a strategy for using multiple tables to
>> present one large "virtual" table to end users? Is there a way to
>> chain tables together to have an endless number of columns? Is this
>> something that can be done through SQL statements? Any advice,
>> examples or documentation on such a strategy would be greatly
>> appreciated.
>> Thanks,
>> Patrick
> Hi Patrick,
> This appears to me to be an arbitrary limit in Derby, one which we could
> investigate lifting. To track this issue, I have filed
> https://issues.apache.org/jira/browse/DERBY-5781. This kind of change would
> have to appear in a feature release. The 1012 limit also applies to the
> number of columns in a SELECT list. This is another arbitrary limit which we
> should consider lifting:
> https://issues.apache.org/jira/browse/DERBY-5782
> Thanks,
> -Rick

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