1. 12/9/2018 6:15 AM © 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

2. DAT327 SQL Server 2005 (Codenamed “Yukon”): Inside XQuery
Michael Rys, Arpan Desai
Program Managers SQL Server XML Technologies
Microsoft Corporation
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

3. Usage Of XML →Transport, Store and Query XML data Data exchange
12/9/2018 6:15 AM
Usage Of XML
Data exchange
Business-to-business (B2B), business-to-consumer (B2C), application to application (A2A)
XML is ubiquitous, extensible, platform independent transport format
Content management
Documents
Mail Messages
Data/view separation Documents, style sheets, transforms
Messaging
Simple Object Access Protocol (SOAP)
→Transport, Store and Query XML data
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

4. XML Query Mechanisms Status quo
12/9/2018 6:15 AM
XML Query Mechanisms Status quo
XPath 1.0
W3C Recommendation
Used in SQL Server 2000: SQLXML and OpenXML
Navigation, no reshaping
Limited knowledge about types
XSLT
Data-driven reshaping (uses XPath)
MSXML, System.XML
Hard to author and optimize for large amount of data
No data modification language (DML)
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

5. XML Query Mechanisms XQuery
12/9/2018 6:15 AM
XML Query Mechanisms XQuery
Functional, declarative query language
Combines XPath with node construction
Operates on (XML Schema-)typed and unconstrained XML
Designed to operate on large amount of data
Optimizable
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

6. XQuery History Dec 1998: W3C Workshop on Querying XML
12/9/2018 6:15 AM
XQuery History
Dec 1998: W3C Workshop on Querying XML
Sep 1999: Start of W3C XQuery WG
Nov 2003: XQuery Data Model, Functions and Operators, Syntax and Semantics in Last Call
Summer 2004 (expected): First Working Draft of XQuery Full-Text language proposal
End of 2005 (expected): XQuery (without Full-Text, DML) in recommendation
During 2006/7 (expected): Full-Text, DML in recommendation
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

7. XQuery Example declare namespace n = "http://example.com/ns1";
for $s in
= >= 3]
Where $s/n:heading
return
<topic>{data($s/n:heading)}</topic>
Query Prolog
Query Body
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

8. XQuery Features FLWOR: FOR / LET / WHERE / ORDER BY / RETURN FOR LET
12/9/2018 6:15 AM
XQuery Features
FLWOR: FOR / LET / WHERE / ORDER BY / RETURN
FOR
LET
WHERE
ORDER BY
RETURN
Includes XPath 2.0 = 123])
Element constructors (<topic>{…}</topic>)
Order-preserving operators
Input order (FLWR)
Document order (XPath, union)
Statically (or dynamically) typed, Strong typing with schema, weak typing without schema
SQL:
SELECT
FROM
WHERE
ORDER BY
& SET
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

9. XML Schema As Type System
12/9/2018 6:15 AM
XML Schema As Type System
XML Schema (W3C standard)
Rich mechanism for type definitions and validation constraints
Can be used to constrain XML documents
Benefits of typed data
Guarantees shape of data
Allows storage and query optimizations
XML type system
Store XML schemas in system metadata
See DAT319 for more information
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

10. 12/9/2018 6:15 AM
XQuery Language
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

11. XML Data Modification Insert, update, and delete XQuery extensions
XML sub-tree modification:
Add or delete XML sub-trees
Update values
Generate consistent state
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

12. XML-DML: insert replace value of delete
12/9/2018 6:15 AM
XML-DML:
insert
replace value of
delete
delete /Customer/Order[id = 42]
insert <notes/> into /Customer
replace value of (/Customer/name)[1] with “Nils”
insert <notes/> as last into /Customer
Customer
insert <notes/> as first into /Customer
notes
notes
insert <notes/> before /Customer/name
name: xs:string
Order
notes
insert <notes/> after /Customer/name
“Janine”
“Nils”
id: xs:int
Target needs to be statically one node 42
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

13. XQuery And XML-DML In SQL Server 2005
12/9/2018 6:15 AM
XQuery And XML-DML In SQL Server 2005
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

14. XQuery And XML-DML In SQL Server 2005
12/9/2018 6:15 AM
XQuery And XML-DML In SQL Server 2005
Beta2 is aligned on Nov XQuery Last Call working draft
Added XML Data Modification
Applies to single XML data type instance
Methods on XML data type:
query(), value(), exist(), modify(), nodes()
Use SQL to iterate over collection of instances (XML-typed column)
Can refer to relational data
Take advantage of Schema-collection information to operate on typed XML data
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

15. 12/9/2018 6:15 AM
XQuery: value()
Extracts an XQuery value into the SQL value and type space SELECT T.x.value( = >= ’int’) FROM T
Expression has to statically be a singleton
String value of atomized XQuery item is cast to SQL type
SQL type has to be SQL scalar type
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

16. 12/9/2018 6:15 AM
XQuery: nodes()
Provides OpenXML-like functionality on XML data type column in SQL Server 2005
Returns a row per selected node
Each row contains a special XML data type instance that
Has the context node set to the selected node
Preserves the original structure and types
Can only be used with the XQuery methods, count(*), IS (NOT) NULL (not modify())
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

17. sql:column()/sql:variable()
12/9/2018 6:15 AM
sql:column()/sql:variable()
Map SQL value and type into XQuery values and types in context of XQuery or XML-DML
sql:variable(): accesses a SQL variable int select * from T where
sql:column(): accesses another column value tables: T(key int, x xml), S(key int, val int) select * from T join S on T.key=S.key where
Restrictions in SQL Server “Yukon”:
No XML, CLR UDT or deprecated text/ntext/image
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

18. 12/9/2018 6:15 AM
XQuery: modify()
Used with SET: xml update T set T.xdoc.modify(‘insert <b/> into /a’) where T.id=1
Relational row-level concurrency: whole XML instance is locked
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

19. XQuery In SQL Server 2005 Subset of Standard implemented. For example:
No LET
No user-defined XQuery functions
Subset of XQuery built-in functions
No XQuery validation (use XML datatype validation)
No expression on a constructed node
Dynamic errors are mapped to empty sequence
No XQuery joins across different XML instances (combine instances using FOR XML)
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

20. Guidelines And Best Practices XQuery and XML-DML in SQL Server 2005
12/9/2018 6:15 AM
Guidelines And Best Practices XQuery and XML-DML in SQL Server 2005
Exploit type information if available
Use indices
Use XQuery for property promotions
Static typing provides performance benefits and early error discovery
Use [1] or explicit FLWR to avoid static errors due to cardinality mismatch
Use explicit casts to avoid static type errors
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

21. XQuery In .NET Framework 2005
Beta 1 is aligned on Nov XQuery Last Call working draft
New common query architecture
Both XSLT and XQuery compiled down to MSIL
Utilizes schema information from XmlSchemaSet
Supports embedding of T-SQL for easy retrieval of data from SQL Server
Supports CLR extension objects to enable highly custom functionality
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

22. Supported XML Sources XML 1.0 XmlReader XPathNavigator
12/9/2018 6:15 AM
Supported XML Sources
XML 1.0
Files, streams, etc.
XmlReader
Can be implemented streaming over custom formats (ex: binary XML, ASN.1)
XPathNavigator
Can be implemented random access over custom structures (ex: registry, assembly metadata)
sql:query() extension function
Enables easy retrieval of relational data from SQL Server for processing in XQuery
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

23. XQuery in the .NET Framework 2.0
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

24. 12/9/2018 6:15 AM
sql:query()
Enables utilization of T-SQL to retrieve data for processing in XQuery
Can utilize FOR XML queries
Also supports client side FOR XML
Extremely useful for legacy stored procs
T-SQL queries can be parameterized
We don’t alter query string
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

25. 12/9/2018 6:15 AM
XQuery In System.Xml
Larger portion of standard implemented. Differences in support:
LET
User-defined XQuery functions
Dynamic errors available
Joins across different XML sources allowed
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

26. More information on XML datatype Whitepapers and other information
12/9/2018 6:15 AM
More information on XML datatype
DAT319 Presentation
Whitepapers and other information
Newsgroup
news:microsoft.public.sqlserver.xml
W3C XQuery
Our contact information
Weblog:
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

27. Exclusive TechEd Offer! Receive Beta 2 of SQL Server 2005
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Next Steps: SQL Server 2005
Exclusive TechEd Offer!
Receive Beta 2 of SQL Server 2005
Register for SQL Server 2005 Beta 2 at:
Visit the SQL Server 2005 website:
Learn more about SQL Server 2005 at TechEd
Hands On Labs
Rooms 6E and 6F
13 Hands On Labs
Ask the Experts
Track Cabanas located around CommNet
Experts Available All Week
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

28. Please fill out a session evaluation on CommNet
12/9/2018 6:15 AM
Please fill out a session evaluation on CommNet
Q1: Overall satisfaction with the session
Q2: Usefulness of the information
Q3: Presenter’s knowledge of the subject
Q4: Presenter’s presentation skills
Q5: Effectiveness of the presentation
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.

29. © 2004 Microsoft Corporation. All rights reserved.
12/9/2018 6:15 AM
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.
© 2004 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.