Learn More About SQL Server IO and Query Tuning in These Webcasts

KKline — Fri, 14 Dec 2012 18:50:00 GMT

I'm doing two new webcasts next week on Wednesday, December 19th, one in the morning and the other after lunch.

SSDs are a Game Changer for SQL Server Storage

No, session is not exclusively about SSDs. But this is my first session on IO and storage tuning that emphasizes SSDs over hard disks. As Bob Dylan said "Times, they are a'changin'". This session on Wednesday, December 19th at 11:30 AM EST, sponsored by Astute Networks, takes you through all of the basics of storage and IO tuning, regardless of the underlying storage technology. I'll show you how SQL Server handles storage structures, how to identify IO activity on Windows and SQL Server, and best practices for minimizing IO bottlenecks. Register now for: Storage IO Best Practices for SQL Server and a New Approach to Solving Application Performance Issues.

Write Better SQL Queries

The next webcast on Wednesday, December 19th at 2 PM EST, is with me, Aaron Bertrand (Twitter | Blog) and SQLCruise Impresario & Microsoft MVP Tim Ford (Twitter | Blog) as we take you through the query tuning process, discussing important DMVs to use during query tuning, as well as demonstrating several essential query tuning techniques that every SQL developer should know. Not only are we presenting an hour of top quality technical content, we’ll also be giving away some cool prizes, including the grand prize of a paid registration for the upcoming SQLCruise Miami, a $1,395 value! Register now for: SQL Server Query Tuning Best Practices, Hosted by Kevin Kline and Aaron Bertrand with special guest Tim Ford

I hope to see you at both of these sessions next week! Best regards,

-Kev

-Follow me on Twitter!

Everybody Needs a Test Harness

KKline — Mon, 31 Oct 2011 14:17:00 GMT

When you're developing new Transact-SQL code or modifying some existing code, do you just launch directly into programming?

I know that I did just that, for years. It wasn't until I was trying to performance tune some existing code that I realized I hadn't actually taken caching of data and execution plans into account. So all those modified stored procedures that I was so proud of might not actually be faster than the first generation of procedures because I hadn't checked to ensure that I was testing cached programs against uncached programs (and, by extension, the data used by those programs). That's easy enough to fix with a test harness. Test harness were originally an actual, physical harness used by engineers to clamp down parts of an electrical or mechanical device they were prototyping. Ours is no different. It locks down all of the assumptions about our code (like my early, false assumption that I didn't need to clear the caches) and adds a metric or two for good measure - literally - so we can better measure what's happening in that code.

Here's what my test harness looks like:

/* Transact-SQL test harness by Kevin Kline, http://KevinEKline.com, Twitter at kekline */

/* Flush dirty pages from the buffer to the database files. */

CHECKPOINT;

/* Flush the data cache and procedure cache, respectively. For DEV environments only! */

DBCC DROPCLEANBUFFERS;

DBCC FREEPROCCACHE;

/* Enable statistics tracking for IO and timings. Remember, SET commands remain enabled during a session until disabled. */

SET STATISTICS IO ON;

SET STATISTICS TIME ON;

-- Whatever SQL code you'd like to process goes below.

SELECT SalesOrderID

FROM Sales.SalesOrderHeader H

WHERE CustomerID = 344

GO

SET STATISTICS IO OFF;

SET STATISTICS TIME OFF;

/* Textual Execution Plans, if desired.

SET SHOWPLAN_TEXT ON;

SET SHOWPLAN_TEXT OFF;

*/

I also like to include the execution plans a lot of the time. You might wonder why I don't save the execution plans for the GUI in SSMS? Well, I'm a big advocate of scripting in general because I like to automate activities. By pulling the execution plans using scripts, I can use SQLCMD to schedule a large number of query executions during the evening and have the results ready for analysis when I come back into the office in the morning. Workin' smarter, not harder, Baby!

So how does this test harness work for you? Do you use other elements in yours? If so, share your experiences here!

Thanks,

-Kevin

-Follow me on Twitter

Search results matching tags 'Performance', 'Troubleshooting', 'Developer', and 'DBA'

Learn More About SQL Server IO and Query Tuning in These Webcasts

SSDs are a Game Changer for SQL Server Storage

Write Better SQL Queries

Everybody Needs a Test Harness