1. Practical Uses and Optimization of New T-SQL Features in Microsoft SQL Server 2012 Tobias Ternstrom DBI308

2. Program Manager, SQL Server Jan Engelsberg janeng@microsoft.com

3. Agenda Key generation Calculations & AggregationsCommon tasks Exceptions & Messages

4. Key generation SQL Server 2012

5. CREATE SEQUENCE [ schema_name. ] sequence_name [ AS { | } ] [ START WITH ] [ INCREMENT BY ] [ MINVALUE | NO MINVALUE ] [ MAXVALUE | NO MAXVALUE ] [ CYCLE | NO CYCLE ] [ CACHE [ ] | NO CACHE ] NEXT VALUE FOR [ schema_name. ] sequence_name [ OVER ( ) ] EXEC sp_sequence_get_range …

6. Key generation in action

7. Guaranteed to be globally unique Can be made sequential Caveats! Cannot be guessed (when not sequential) Use any data type for keys (for ex. strings) Can guarantee a continuous range of values (no wholes) Including ranges Serializes number generation across transactions Supports all integer types, starting from TINYINT up to DECIMAL(38, 0) Supports range reservation Caching “knob” for performance tuning Large; requires 16 bytes storage Many systems don’t natively support GUIDs Causes fragmentation Sequential generation cannot be guaranteed even with NEWSEQUENTIALID () Access to the identifier is serialized across transactions Performance issue Not native RDBMS functionality, more code Cannot guarantee a continuous range of values E.g. can “lose” values because of dirty shutdowns or rollbacks GUIDs Pros Cons Separate tableSequences

8. Exceptions & Messages SQL Server 2012

9. THROW,, ; Always aborts the batch Batch aborts if not in SET XACT_ABORT ON where it transaction-aborts Does not automatically use sys.messages Is even spelled correctly! re-THROW BEGIN CATCH …; THROW; END CATCH

10. Exceptions & messages in action

11. Flexible Well known Logs events without sending a message to the client Multiple behaviors, easy to get it wrong Not supported on SQL Azure RAISERROR Pros Cons xp_logevent Flexible, supports the attributes you specify Transactions need to be managed so log records are not rolled back Logging table Easy to use Similar behavior to other programming languages Re-throw capabilities Less flexible than RAISERROR THROW

12. SQL Server 2012 Calculations & Aggregations

13. TranIdAccountIdTranDateAmount 112011-12-19120 222011-12-20500 332011-12-21430 412011-12-2695 522011-12-2750 632011-12-2825 712012-01-02250 822012-01-0325 932012-01-045000 1012012-01-0975

14. 3 trn. avg. TranIdAccountIdTranDateAmount 112011-12-19120 222011-12-20500 332011-12-21430 412011-12-2695 522011-12-2750 632011-12-2825 712012-01-02250 822012-01-0325 932012-01-045000 1012012-01-0975 120.000 310.000 350.000 341.666 191.666 56.666 108.333 100.000 1758.333 1700.000 The FRAME Window PARTITION The FRAME Window FRAME

15. BalanceTranIdAccountIdTranDateAmount 112011-12-19120 412011-12-2695 712012-01-02250 1012012-01-0975 1312012-01-16125 1612012-01-23175 222011-12-20500 522011-12-2750 822012-01-0325 1122012-01-10125 120 215 465 540 665 840 500 550 575 700 Window PARTITIONs Window FRAME

17. Calculations & Aggregations in action

18. Approach that is commonly used in other programming languages Follows the SQL set based paradigm Improved optimization Easy to write Following the SQL set based paradigm Not set based Only individual queries are optimized, not the operation as a whole Many lines of code  Higher risk for bugs Bad performance due to plan with N 2 complexity solution Non-trivial to write Not always the optimal solution Not all queries can be easily rewritten to leverage window functions Imperative approach Pros Cons Correlated sub queriesWindow Functions

19. Common tasks SQL Server 2012

22. SELECT... ORDER BY... OFFSET ROWS FETCH NEXT ROWS ONLY EXECUTE [WITH [,...n ]] { RESULT SETS {UNDEFINED|NONE|( )} } ::= { | AS OBJECT [.] {table_name | view_name | tvf} | AS TYPE [schema_name.]table_type_name | AS FOR XML | (…) [,...n ]}

23. Common tasks in action

24. Questions ?

25. (DBI311) Microsoft SQL Server Data Tools: Database Development from Zero to Sixty (DBI409)SQL Server Columnstore Performance Tuning (DBI21-HOL ) What's New in T-SQL for Microsoft SQL Server 2012 (DBI31-HOL) Getting Started with SQL Server Data Tools in Microsoft SQL Server 2012 (DBI07-TLC ) Microsoft SQL Server: Cloud on Your Terms - Optimized Productivity Find me in the TLC area at: 7:30 to 9p, Tuesday 10:30a to 1p, Wednesday 12:30 to 3:30p

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