sofia, bulgaria | 9-10 october tsql enhancements in sql server 2005 stephen forte cto, corzen inc...

Sofia, Bulgaria | 9-10 October

TSQL Enhancements in SQL Server 2005TSQL Enhancements in SQL Server 2005

Stephen Forte

CTO, Corzen Inc

Microsoft Regional Director NY/NJ (USA)

Stephen Forte

CTO, Corzen Inc

Microsoft Regional Director NY/NJ (USA)


Speaker.Bio.ToString()● CTO and co-Founder of Corzen, Inc● Microsoft RD, MVP and INETA Speaker ● International Conference Speaker for 9+

Years ● Wrote a few books on databases and

development

●SQL Server 2005 Developers Guide (MS Press)

● Co-moderator & founder of NYC .NET Developers Group

●http://www.nycdotnetdev.com● Former CTO of Zagat Survey


AgendaAgenda

● Introduction

● New data types

● XML, varchar(max)

● More expressive power

● Top enhancements

● Recursive query and CTE

● PIVOT/APPLY

● Transact abort handling

● Introduction

● New data types

● XML, varchar(max)




● PIVOT/APPLY



IntroductionIntroduction

● TSQL is here to stay, even though you can code SPs in CLR Languages● Richer data types

● XML, date/time types, varchar(max)● More expressive power

● Recursive queries, TOP (<expression>), new relational operators, etc.

● Very cool and long awaited features● Transaction abort handlers, LOB

enhancements through varchar(max)

● TSQL is here to stay, even though you can code SPs in CLR Languages● Richer data types

● XML, date/time types, varchar(max)● More expressive power

● Recursive queries, TOP (<expression>), new relational operators, etc.

● Very cool and long awaited features● Transaction abort handlers, LOB

enhancements through varchar(max)


IntroductionSQL versus CLRIntroductionSQL versus CLR

● Full interoperability with CLR features

● T-SQL → CLR → T-SQL

● When to use CLR versus T-SQL

● Computation intensive: computational logic, arithmetic operations: CLR

● Data access intensive: T-SQL

● Full interoperability with CLR features

● T-SQL → CLR → T-SQL

● When to use CLR versus T-SQL

● Computation intensive: computational logic, arithmetic operations: CLR

● Data access intensive: T-SQL


AgendaAgenda

● Introduction

● New data types

● XML, Varchar(max)




● PIVOT/APPLY

● Queuing enhancements

● Introduction

● New data types





● PIVOT/APPLY

● Queuing enhancements


New Date/Time TypesFrequently asked for…New Date/Time TypesFrequently asked for…

● XML

● (n)varchar(Max)

● XML

● (n)varchar(Max)


Varchar(max) TypeVarchar(max) Type

● Extension to varchar, nvarchar, varbinary up to 2GB

● Uses MAX size specifier

CREATE TABLE myTable

(Id int, Picture varbinary(max))

● Alternative to text/ntext/image

● No text pointer support

● Extension to varchar, nvarchar, varbinary up to 2GB

● Uses MAX size specifier

CREATE TABLE myTable

(Id int, Picture varbinary(max))

● Alternative to text/ntext/image

● No text pointer support



● SELECT + DML

● Conversions

● Concatenation

● Comparisons

● Triggers

● SELECT + DML

● Conversions

● Concatenation

● Comparisons

● Triggers

● Aggregates

● Functions

● Parameters

● Variables

● Aggregates

● Functions

● Parameters

● Variables

Brings together programming model Brings together programming model of small and large valuesof small and large values



● All string functions operate on varchar(max)

● SUBSTRING used to read chunks

● UPDATE statement enhanced to support update of CHUNKS

UPDATE myTable

SET Picture::Write(@newchunk, @offset, @remove)

● All string functions operate on varchar(max)

● SUBSTRING used to read chunks

● UPDATE statement enhanced to support update of CHUNKS

UPDATE myTable

SET Picture::Write(@newchunk, @offset, @remove)


XML DatatypeXML Datatypevarchar(max)varchar(max)


AgendaAgenda

● Introduction

● New data types





● PIVOT/APPLY


● Introduction

● New data types





● PIVOT/APPLY



Top EnhancementsEnhancement from SQL Server 2000Top EnhancementsEnhancement from SQL Server 2000

● In SS 2000: SELECT TOP <const.>

● In Yukon: SELECT TOP (<expression>)

● Also supported in INSERT, UPDATE, DELETE

● <expression> may be for example a variable, subquery (self-contained returning numeric scalar)

● In SS 2000: SELECT TOP <const.>

● In Yukon: SELECT TOP (<expression>)

● Also supported in INSERT, UPDATE, DELETE

● <expression> may be for example a variable, subquery (self-contained returning numeric scalar)


Top EnhancementsPartial Deprecation of SET ROWCOUNT in SQL 2005

Top EnhancementsPartial Deprecation of SET ROWCOUNT in SQL 2005

● SET ROWCOUNT still works for SELECTS

● SET ROWCOUNT is ignored in UPDATE, DELETE, INSERT unless the server is running in backward compatibility mode

● In SQL 2000 you had to add TOP to every single UPDATE, DELETE and INSERT query plan because we don’t know if it will be activated at query run time

● SET ROWCOUNT still works for SELECTS

● SET ROWCOUNT is ignored in UPDATE, DELETE, INSERT unless the server is running in backward compatibility mode

● In SQL 2000 you had to add TOP to every single UPDATE, DELETE and INSERT query plan because we don’t know if it will be activated at query run time


Top EnhancementsTop Enhancements


AgendaAgenda

● Introduction

● New data types





● PIVOT/APPLY


● Introduction

● New data types





● PIVOT/APPLY



Recursive Queries And CTECommon table expressionRecursive Queries And CTECommon table expression

● Very similar to a view, but imbedded in the query

WITH CTE_name (colname1, colname2,..) as (SELECT …..) SELECT ….<the main query that references CTE_name>● May be used in front of SELECT, UPDATE,

DELETE, INSERT

● Several CTEs may be in a single statement

● There must be semicolon in front of the WITH if this is not the first statement in batch (takes care of ambiguities)

● Very similar to a view, but imbedded in the query

WITH CTE_name (colname1, colname2,..) as (SELECT …..) SELECT ….<the main query that references CTE_name>● May be used in front of SELECT, UPDATE,

DELETE, INSERT

● Several CTEs may be in a single statement

● There must be semicolon in front of the WITH if this is not the first statement in batch (takes care of ambiguities)


Recursive Queries And CTERecursive queryRecursive Queries And CTERecursive query

● This is the main reason we have introduced the CTEs

● Recursion is achieved by allowing the CTE refer to itself

● Such CTE must have special syntax

WITH REC_CTE as

(SELECT1 UNION ALL SELECT2)

● This is the main reason we have introduced the CTEs

● Recursion is achieved by allowing the CTE refer to itself

● Such CTE must have special syntax

WITH REC_CTE as

(SELECT1 UNION ALL SELECT2)


Recursive Queries And CTERecursive queryRecursive Queries And CTERecursive query

● SELECT1 does not refer to REC_CTE and it is called Anchor Member

● SELECT2 references REC_CTE and is called Recursive Member

● Semantics● Execute the Anchor member, get the set T0

● Execute the Recursive member with Ti as an input Ti+1 as an output

● Repeat previous step until you get empty set (say Tn+1)

● The result is UNION ALL of T0 to Tn

● SELECT1 does not refer to REC_CTE and it is called Anchor Member

● SELECT2 references REC_CTE and is called Recursive Member

● Semantics● Execute the Anchor member, get the set T0

● Execute the Recursive member with Ti as an input Ti+1 as an output

● Repeat previous step until you get empty set (say Tn+1)

● The result is UNION ALL of T0 to Tn


Recursive Queries And CTETidbitsRecursive Queries And CTETidbits

● We are using ANSI syntax and semantics

● Watch for “runaway recursion” – there is a server-wide limit with default 100 levels

● You can overrule the limit on your query by OPTION (MAXRECURSION n)● N=0 means no limit!● You can programmatically set your

own limit by a predicate on the Recursive Member

● We are using ANSI syntax and semantics

● Watch for “runaway recursion” – there is a server-wide limit with default 100 levels

● You can overrule the limit on your query by OPTION (MAXRECURSION n)● N=0 means no limit!● You can programmatically set your

own limit by a predicate on the Recursive Member


Common Table Common Table ExpressionsExpressions


AgendaAgenda

● Introduction

● New data types





● PIVOT/APPLY


● Introduction

● New data types





● PIVOT/APPLY



New Relational Operators PIVOT and UNPIVOTNew Relational Operators PIVOT and UNPIVOT

● PIVOT

● Transforms a set of rows to columns

● Similar to Access TRANSFORM

● Useful for open schemas/OLAP scenarios

● UNPIVOT

● Reverse operation of PIVOT

● PIVOT

● Transforms a set of rows to columns

● Similar to Access TRANSFORM

● Useful for open schemas/OLAP scenarios

● UNPIVOT

● Reverse operation of PIVOT


New Relational OperatorsPIVOTNew Relational OperatorsPIVOT

SELECT *

FROM table PIVOT(MIN(PropVal) FOR PropName IN ([Name], [Author]))

SELECT *

FROM table PIVOT(MIN(PropVal) FOR PropName IN ([Name], [Author]))

ObjID

PropName PropVal

1 Name x.doc

1 Name spec.doc

1 CrDate 12/3/2001

2 Name sales.xls

2 Author Mary Higgins

ObjID Name Author

1 Spec.doc NULL

2 Sales.xls Mary Higgins


New Relational OperatorsAPPLYNew Relational OperatorsAPPLY

● Evaluates a table-valued function for every row of its left input

● Rows: UNION of all evaluations

● Columns: Columns of left input + columns of TVF

● Useful in conjunction with complex data types (e.g., spatial)

● Evaluates a table-valued function for every row of its left input

● Rows: UNION of all evaluations

● Columns: Columns of left input + columns of TVF

● Useful in conjunction with complex data types (e.g., spatial)


Pivot (static and dynamic)Pivot (static and dynamic)


AgendaAgenda

● Introduction

● New data types





● PIVOT/APPLY


● Introduction

● New data types





● PIVOT/APPLY



Tran Abort HandlingTran Abort Handling

● Catch Transaction Abort Errors

● TRY / CATCH model

● No loss of transaction context

● “Doomed” Transaction

● Catch Transaction Abort Errors

● TRY / CATCH model

● No loss of transaction context

● “Doomed” Transaction


Tran Abort HandlingSyntaxTran Abort HandlingSyntax

BEGIN TRY

sql statement [,…n]

END TRY

BEGIN CATCH TRAN_ABORT


END CATCH

BEGIN TRY


END TRY

BEGIN CATCH TRAN_ABORT


END CATCH


Tran Abort HandlingDetailsTran Abort HandlingDetails

● @@error can be examined as first statement in CATCH block

● No DML or DDL succeeds in a Doomed Transaction

● ROLLBACK allows creation of new transaction context

● @@error can be examined as first statement in CATCH block

● No DML or DDL succeeds in a Doomed Transaction

● ROLLBACK allows creation of new transaction context


RAISERROR WITH TRAN_ABORTRAISERROR WITH TRAN_ABORT

● New option for RAISERROR

● Aborts transaction and batch

● If executed within TRY block, control moves to CATCH block

● @@error is set and can be examined in CATCH block

● New option for RAISERROR

● Aborts transaction and batch

● If executed within TRY block, control moves to CATCH block

● @@error is set and can be examined in CATCH block


Questions?Questions?


Thanks!Thanks!

● Please fill out your evaluation form!

● [email protected]

● Please put (TSQL in the subject)

● Please fill out your evaluation form!

● [email protected]

● Please put (TSQL in the subject)

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