The document outlines a presentation by Shehap El-Nagar, a SQL Server expert, on performance analysis and optimization techniques for SQL databases. It discusses strategies for capturing and analyzing expensive queries, optimizing T-SQL practices, and tuning indexes while providing various tools and methodologies for performance management. Additionally, it covers alternatives to common practices that negatively impact performance, such as using temp tables, union commands, and scalar functions.

1. 1/23/2014 by Shehap El Nagar

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3. Shehap EL-Nagar
I am MVP,MCTS , MCITP SQL Server, I am DB consultant and Architect for lots of Banking, Telecom ,Ministries and
governmental organizations all over Gulf ,also he has deep knowledge about T-SQL performance , HW Performance
issues, Data Warehousing solutions , SQL Server Replication, Clustering solutions and Database Designs for different kinds
of systems ...
The founder of the biggest SQL Server community all over the middle east http://sqlserver-performance-tuning.net/ , you
can watch its success memories at http://www.youtube.com/user/ShehapElNagar
Moderator and author at http://www.sql-server-performance.com ,
, the 1st SQL Server Author at MSDN Arabia http://msdn.microsoft.com/ar-sa/library/jj149119.aspx
, Speaker at SQL Saturday Events worldwide , local events at Saudi Arabia , many online events , more than 90 video
tutorials and also many private sessions for .net developers and Database Administrators
And also influent participator at Microsoft Forums of SQL Server at http://social.technet.microsoft.com.
More about him , you can find him on MVP Microsoft site http://mvp.microsoft.com/en-us/mvp/Shehap%20El-Nagar5000188 .
You can contact him at the below contacts :Mail :idgdirector@yahoo.com ….Cellular phone :00966560700733

4. Agenda and Overview:
First :How to Start Performance Analysis..?
•
•
How to Capture Expensive Queries..?
How to analyze them to find out performance bottlenecks..?
Second :T-SQL Optimization by checking and replacing poor T-SQL
Practices
1-The practice of Temp Tables and table variables Practice
2-The practice of Union Command
3-The practice of MTVF
4-The practice of Scalar Function
5-The Practice of Views
6-Fast Performance means
Third: Index Tuning by checking and replacing all poor Indexes
(Next Session)

6. •
How to Capture Expensive Queries..?
Microsoft /Third
party tools
SQL Server
• APM (Application Performance Management)
• Alerts-Based Performance monitors
•
•
•
•
SQL Profiler / SQL Tracer
Activity Monitor / SQL Server Agent Alerts
UCP (Utility Control Point ) of 2008 R2
Dynamic Management Views (DMVs)

7. Microsoft /Third party tools
1- APM (Application Performance Management) :
•
•
•
•
•
•
•
Dyntrace /Gomez by Compuware
Quest software tools
Redgate
DLD (SQL Deadlock Detector)
SQL Trace Analyzer of SQL Server Solutions.com
RML
SQLIOSim (SQL IO Simulator )
(Exists per SQL Server 2008 Installation directory)
2- Alerts–Based Performance tools :
• SCOM (System Centralized Operation Manager)
• Application Manager /Operation Manager

8. •
SQL Server Techniques /Tools
1- SQL Profiler / SQL Tracer:
•
•
•
High impact on DB Server
Standstill cases if profiler is capturing frequent events on DB Server
SQL Tracer is better coz it can save 70 % of Network bandwidth
2- Activity Monitor of SQL Server 2008 / SQL Server Agent Alerts
3-UCP (Utility Control Point of SQL Server 2008 R2) which can monitor:
• SQL Server 2008
• SQL Server 2008 R2
• SQL Server 2012
4- Dynamic Management Views (DMVs) and Dynamic Management
Functions (DMFs)

9. •
How to Analyze Expensive Queries..?
• Database Engine Tuning Advisor (Fundamental Way)
Query-Level
• Query Execution Plans (Advanced Way)

10. 1- Update Statistics/
Rebuild indexes
Update statistics
Online Index Rebuild
Find out Poor Execution
Elements
2- Display Actual/Estimated
Query Execution Plan
Identify Relevant tables
Check how they are used within Query
(Joins/Where /Select /
Scalar functions/Order By/Group By)
3- T-SQL Optimization
4- Index Tuning
Alter these Elements by
Address all poor T-SQL practices
Display Again Query Execution
plan to tune finally indexes
Query Execution Plan
(Advanced Way)
Main Poor Query
execution Elements :
•Table Scan
•Index Scan
•TVF Scan
•Key Lookup/bookmark lookup
•RID lookup
•Hash Match
•High IO /CPU cost of indexes

12. 1 –The Practice of Temp Tables

13. Impacts of Temp tables and Tables variables
•
Impact on I/O subsystem resources (SAN or local storage)
•
Standstill case due to much Page Latch waits.
•
Much Temp Contention of SGAM (Shared Global Allocation Mapping) , GAM (Global A
, PFS (Page Free Space)
•
Impact on CPU utilization due to much Cxpacket waits resulted of insufficient
indexing of those temp tables.

14. Healthy Cases of Temp Table usage
1.
Small Volume (Records Number and size) of data entity to be
inserted to Temp tables
2.
Sufficient indexing on Temp Tables (clustered or non clustered)

15. Alternatives of Temp Tables
1.
CTE expression
2.
Sub queries.
3.
Physical table (Schema Table) if relevant data entity are
seldom changed.
4.
Table Parameters (New 2008 features)

16. 2 –The Practice of Union Commands

17. Impacts of Union Command
•
Impact on I/O subsystem resources (SAN or local storage)
•
Standstill case due to much Page Latch waits + Page I/O latch waits
•
TempDB contention as explained before

18. •Alternatives of Union
•
•
Controlling no of unions commands according to
parameters passed from end users.
•
Ordering Union Commands according to data volume of
each select
•
Case When Commands
•
Dynamic T-SQL queries .
•

19. 3- The Practice of MTVF

20. Cases of MTVF Impact
Usage of MTVF within Joins
Usage of MTVF within Where conditions

21. How to overcome MTVF Impacts…?
•Transferring
all of MTVF (Multiline TVF) to ITVF (Inline TVF) as much
as possible
•Selecting the Output of MTVF into Temp Tables
•Creating
•Then
•You
Sufficient indexes on these Temp tables
Replacing MTVF everywhere with These Temp tables
should to test it along with your T-SQL queries to check IO cost of
Temp tables

22. 4- The Practice of Scalar functions

23. Alternatives :
1- Temp Tables as used before with MTVF
2- Persisted deterministic Computed Columns with Sufficient indexing
for them
3- Creating Update Jobs on the appropriate columns to get values of scalar
functions

24. How to get a Persisted deterministic Computed Columns…?
•Not
to use any aggregative functions of other records.
•Not to use functions that call external system procedures
•Not to use any functions of other fields of other tables.
•To use much better System functions not UDF
How to create index on them..?
Precise Columns only can be put within key column part within index design
Imprecise Columns like decimal ones can be added within include columns part

25. 5- The Practice of Views

26. Impacts:
•Much CPU Consumption & CXPacket waits particularly more for Huge data cases
and Stressed workload cases
•Dramatic performance degradation for the entire of DB Server due to CPU
bottleneck

27. Alternatives:
1- Sub queries filtered with the appropriate conditions
2- CTEs (Common Table Expressions)
3- Indexed Views but this option has some restrictive limitations to
enjoy with indexing feature such as :
•Views should be based on a single table not multiple tables
•No use for with (nolock) hint or such similar hints
•No usage for any aggregative functions , Top or distinct commands
•WITH SCHEMABINDING should be used
•View should have unique clustered index.

28. 6- Fast Performance Means

29. Update Statistics & Index Rebuild:
Update index statistics to help Query Analyzer selecting the best execution plan
Index rebuild to remove index fragmentations to assure indexes are selected
correctly
Table Hints:
Used to enforce Query execution plan to select specific indexes on certain tables
to let it move with another different Route Map
With (Index (Index_Name),Forceseek,nolock)
With (forceseek (index_Name(Column1, Column2..)))
Query Hints:
Used to enforce the entire of query execution plan to move with another route path
that might be better than the default one:
Option ( Maxdop 4)……….Controllable CPU Consumption
Option ( Hash match) ……Much Faster for Large volume of data
Option ( fast N)…………….Faster Execution plan for the first (N) records
Option (Keepfixed plan)…Save elapsed time of Re-estimating Execution plan

30. Demo Part

31. Q&A
Post your questions at:
http://www.sqlserver-performance-tuning.net/forums/

33. Thank you ..See you again
1/23/2014

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