You misunderstood me. I didn't say that there were no real applications =
using identity constraints. I said that I wasn't aware of any in the =
public domain that could usefully be used for benchmarking.
 
As far as I can see you are conjecturing performance difficulties here =
with no real evidence. I don't think there is any reason to believe that =
the cost of validating identity constraints is likely to be a =
significant obstacle to real applications.
 
Michael Kay
http://www.saxonica.com/


  _____  

From: Le, Yongnian [mailto:yongnian.le@i...] 
Sent: 13 May 2007 17:17
To: Michael Kay; xmlschema-dev@w...
Cc: Jones, Kevin; Yu, Zhiqiang
Subject: RE: is there any formal commercial identity constraint cases



That=E2=80=99s a pity that there is no real application having identity =
constraints, maybe because that feature is quite advanced. Anyway, =
thanks for your info. The differences between identity constraint and =
other regular expressions are mostly listed below, which makes me =
concern the runtime overhead of identity constraint support in the real =
application usage. 

1.     Identity constraint processing creates dependence between =
validations in different SAX events, which make it hard for further =
advanced optimization; while regular expression in schema validation can =
be processed in a single SAX event validation.

2.     Identity constraint requires typed based comparison, which might =
involve a lot of table/value-object/memory management, type conversion =
and string operations during validation; while regular expression =
processing is relatively simple: accepted or not accepted.

 

Best Regards

Yongnian


  _____  


From: Michael Kay [mailto:mike@s...] 
Sent: 2007=E5=B9=B45=E6=9C=8811=E6=97=A5 15:49
To: Le, Yongnian; xmlschema-dev@w...
Cc: Jones, Kevin; Yu, Zhiqiang
Subject: RE: is there any formal commercial identity constraint cases

 

Thanks for the explanation. I'm not aware of any public domain material =
that can be used for performance benchmarking of schema processors, =
whether it's concerned with identity constraints or anything else. Is =
there any particular reason why you think identity constraints should be =
a problem, as distinct from, say, validation of strings against complex =
regular expressions?

 

Michael Kay

http://www.saxonica.com/

 


  _____  


From: Le, Yongnian [mailto:yongnian.le@i...] 
Sent: 11 May 2007 02:43
To: Michael Kay; xmlschema-dev@w...
Cc: Jones, Kevin; Yu, Zhiqiang
Subject: RE: is there any formal commercial identity constraint cases

I mean that whether there is any real customer case which contains =
identity constraint for us to use that as benchmark to measure =
performance of identity constraint support. Currently I only found there =
are hundreds of identity constraint unit cases in w3c XML Test Suite, =
but I am afraid that all of them are not representative enough in the =
real world used by customer. 

 

Best Regards

Yongnian


  _____  


From: Michael Kay [mailto:mike@s...] 
Sent: 2007=E5=B9=B45=E6=9C=8810=E6=97=A5 17:42
To: Le, Yongnian; xmlschema-dev@w...
Cc: Jones, Kevin; Yu, Zhiqiang
Subject: RE: is there any formal commercial identity constraint cases

 

I'm not sure what you mean by "formal", "commercial", or "benchmarking".

 

Michael Kay

http://www.saxonica.com/

 


  _____  


From: xmlschema-dev-request@w... [mailto:xmlschema-dev-request@w...] =
On Behalf Of Le, Yongnian
Sent: 10 May 2007 09:52
To: xmlschema-dev@w...
Cc: Jones, Kevin; Yu, Zhiqiang
Subject: is there any formal commercial identity constraint cases

Hi everyone, 

 

Do you know whether there is any formal commercial identity constraint =
case available for benchmarking? Thanks a lot!

 

"I hear and I forget, I see and I remember, I do and I understand" -- =
quoted by Yongnian

ICSC Compiler

Le, Yongnian

8752-6253