1. Are You There, DBA?
It’s Me, The App Developer

2. Who am I? Jacquelyn Keeper C#, ASP.NET, SQL Server, Oracle
gmail.com
Strategies
Common roadblocks

3. DBA vs. Developer Relationship can be contentious Blame game
Us or them
Work as a team or everyone goes down with the ship.
Us v them
Dba dev roles
users

4. Developers: How to Ask For Data
Provide the query
Reasonable result size
Specify output format
Destructive or long-running query? Warn the DBA!
Use app name in connection string

5. DBAs: How to Provide Data
No screenshots
Readable format
Takeaway

6. Request/Provide Data Takeaways
Few minutes work up front
No wasted time or s

7. Breaking Out of Your Bubble
What causes DBAs and Devs to observe different results?

8. Parameter Sniffing
When a stored procedure is compiled, SQL Server uses the parameter values to create an execution plan.

9. Parameter Sniffing Demo

10. Parameter Sniffing – Demo Screenshot
“USA” as First Parameter
“Canada” as Second Parameter

11. Parameter Sniffing – Demo Screenshot
“Canada” as First Parameter
“USA” as Second Parameter

12. Parameter Sniffing - Takeaways
Performance can vary significantly depending on your parameter values
Make sure DBA and Developer use the same parameter values when troubleshooting

13. Breaking Out of Your Bubble - Take 2
What causes DBAs and Devs to observe different results?

14. Different Clients, Different Plans
Even when executing a stored procedure using the same parameter values, an application may get a different query plan than SSMS.
Different clients, different plans?
Different plans, different results?

15. Default Cache Key Settings
Applications using ADO.NET, ODBC, or OLE DB
SSMS
SQLCMD, BCP, SQL Server Agent
QUOTED_IDENTIFIER ON
OFF
ARITHABORT
Source: Slow in the Application, Fast in SSMS? Understanding Performance Mysteries,

16. Query Plan Cache Demo
Clear query cache. Run proc from SSMS. Show query cache. Rerun proc from SSMS with different parameter value. Show query cache. Run proc from SSMS. Show query cache.

17. Query Plan Cache – Demo Screenshot
Stored procedure executed twice, only 1 plan in cache

18. Query Plan Cache – Demo Screenshot
Run stored procedure from application, 2 plans in cache

19. Detour – My demos aren’t working?!?
Plan cache getting cleared within in a few seconds!
Check SQL Server error log
KB might be affecting you too!
Lock pages in memory option

20. Getting the Execution Plan
Get the actual plan, not the estimate
Use Profiler to capture the application query plan
Using Profiler can cause performance issues!

21. Actual Execution Plan Demo
Have a template ready with the correct events selected

22. Actual Execution Plan – Demo Screenshot

23. Reading the Execution Plan
SQL Sentry Plan Explorer
Integrates with SSMS

24. Techniques for troubleshooting together
Tips & Tricks
Techniques for troubleshooting together

25. Statistics DBA Consider a weekly or monthly job to update statistics.
Developer
Some tables may need frequently updated statistics.

26. Compare Execution Plans
SSMS
Application

27. Query Types Stored Procedures Use whenever possible Easy to change
Dynamic SQL
Sometimes unavoidable
Consider using snippets

28. Get Creative Option Recompile Plan Guides Partition Meetup
Force a good plan to be used
Option Recompile
Work around parameter sniffing
Partition
Force queries to use a single partition
Meetup
In person brainstorming session

29. Learn from each other!

30. DBAs & Developers… this is the beginning of a beautiful friendship!

31. Questions? ?

32. I made use of the following resources:
Credits
I made use of the following resources:
Presentation template by SlidesCarnival
The truly excellent article “Slow in the Application, Fast in SSMS? Understanding Performance Mysteries” by Erland Sommarskog