Re: Annotated schema with views?

OK, thank you for the advice. I got this information of existence checks
from the following article
http://support.microsoft.com/default.aspx?scid=kb;en-us;813955

I have another couple of questions though.

Question 1:
Will SQL 2005 support SQLXML natively and will the generated queries use FOR
XML PATH instead of the bulky FOR XML EXPLICIT. I know of the XML columns,
but I don't want to redo my tables necessarily.

Question 2:
I'm running into limitations in terms of performace with my XSD Schema
because there is simply a lot of elements.

I changed my XML format to be attribute centric and also added a lot of
clustered indexes on the keys and selected elements. This speeded up
tremendously. The problem is I have to add more elements in future and the
containment hierarchy is becoming huge. I ended up writting some logic to
query elements in fragments and add children manually. Will this be better
in SQL 2005 (if question 1 is "yes" ofcourse)?

Question 3:
UpdateGrams doesn't work well with identity columns. I ended using GUIDs
instead. This is fine in my current project, but I have another existing
project I want to convert to use SQLXML with .NET serialization which
depends hugely on identity values... will this be improved in future. I
suppose you can always write XSLT to generate clever SQL script or something
as a work-around, but I like the convenience of updategrams. Let MS do the
query generation work :).

Question 4:
I know AS in 2005 uses XML/A. What is the chances in future of mapping XSD
to cubes instead of using XSLT to get the same effect? I don't know if this
is the right group to pose this question though.

Question 5:
SQL queries FOR XML doesn't support XML Attribute Groups, will this be
supported in future? Or is a XSLT the only way to do this as well?


"Michael Rys [MSFT]" <mrys@xxxxxxxxxxxxxxxxxxxx> wrote in message
news:Ok6LcyDeFHA.640@xxxxxxxxxxxxxxxxxxxxxxx
> Hi Joe
>
> This should not be a problem. Since we do not look at the relational
> schema when we generate the queries, we do not know whether the column can
> be null or not. However, the query optimizier will know about it and this
> optimize these expressions away. Thus, there should be no slow down in
> performance due to these IS NOT NULL checks...
>
> Best regards
> Michael
>
> "Joe" <morbidcamel@xxxxxxx> wrote in message
> news:%23A08G49dFHA.2776@xxxxxxxxxxxxxxxxxxxxxxx
>> My database I am working with is very normalized so I ended up creating
>> views for certain tables which I then use in my XSD schema to select XML
>> from the DB.
>>
>> The problem is the generated query does unecessary existence checks
>> because
>> it doesn't read the underlying table column schema info.. the underlying
>> column is definately marked "NOT NULL".
>> ...
>> (((((_Q6.A32 IS NOT NULL AND (_Q6.A32 =
>> N'11111145-110b-11c4-d8b3-c8c5154c131e') OR _Q6.A32 IS NOT NULL AND
>> (_Q6.A32
>> = N'11111145-110b-11c4-d8b3-c8c5154c131d')) OR _Q6.A32 IS NOT NULL
>> ...
>>
>> How do I get rid of this unecessary checks. Surely it slows down
>> performance
>> of the query.
>>
>>
>>
>
>


.

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