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From Shreyas Kaushik <Shreyas.Kaus...@Sun.COM>
Subject Re: DB2 mode vs. Cloudscape mode
Date Fri, 04 Mar 2005 10:43:05 GMT
Please see below for questions.

~ Shreyas

Satheesh Bandaram wrote:

>Yes, Cloudscape used to allow creating UNIQUE indexes on null columns,
>but in a non-standard way. Old cloudscape used to allow only one NULL
>value in the UNIQUE index, where as, I think the standard required
>multiple NULL values.
>
>I think making Derby handle multiple NULLs in UNIQUE index needs changes
>to store/indexing.
>  
>
What sort of impact on store? How wide will be the impact on store and 
indexing ?

>Satheesh
>
>Jeremy Boynes wrote:
>
>  
>
>>Satheesh Bandaram wrote:
>>
>>    
>>
>>>Yes, you are right... The references to "DB2 mode" is from the past,
>>>leftover comments. There is no distinction between the two.
>>>
>>>      
>>>
>>Did Cloudscape support UNIQUE on possibly null columns? If so, is this
>>a restriction that we can easily remove or is there something deep in
>>the index code that would make this problematic?
>>
>>Also, can anyone think of an issue with making the NOT NULL implicit
>>in a PRIMARY KEY specification (per spec but unlike DB2)?
>>
>>-- 
>>Jeremy
>>
>>
>>
>>    
>>
>
>  
>

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