Prior Winners:

• Lara Rubbelke – (post link | blog | @SQLGal) – Enterprise Policy Management Framework
• Tim Ford – (post link | blog | @SQLAgentMan) – Determine Free Space, Consumed Space, and Total Space Allocated for SQL Server databases

This “award” has (unintentionally) not been handed out in a while but something that I’ve used (or a variation of) for a while now that I think needs to get bumped back up to the top of everyone’s RSS Feed is Mladen Prajdic’s I.D.N.W.C.E.C (a not so catchy acronym that I just came up with).

Immediate Deadlock Notifications Without Changing Existing Code

Mladen describes how to use the server wide deadlock notification (Event Notifications) to capture the deadlock graph (or deadlock chain, deadlock, escalation) to a table as soon as a deadlock occurs (as well as optionally to send an email at time of capture).

Now what I like about this over the more “traditional” way of detecting deadlocks with Trace Flags 1204 and 1222 (MSDN Link) is that we’re able to capture the deadlock graph event like we were running a Profiler trace against the server.  Using trace flags 1204 and 1222 you get all the same information but I’m a picture person….

and as a picture person I much prefer to see the deadlock graph over the “texty” / XMLish type of information you get back from Trace Flags 1204 and 1222.

Big thanks and props to Mladen for this blog post as I’ve come back to it time and time again

If you’d like to chat with me about this or anything else (SQL or other) please leave a comment or hit me up on my Twitter: @ColinStasiuk

Doing More With Less… Policy Based Management

Session Abstract:

Do more with less… sound familiar? In this introduction to Policy Based Management presentation we will be going over what Policy Based Management is and how to use Policy Based Management and a Central Management Server to evaluate your daily, weekly, and monthly checklists against your entire SQL Server farm.  We will be reviewing some of the “out of the box” policies as well as creating some custom policies that you might be interested in evaluating against your SQL Server farm. Finally we will be taking a quick look at how to tie all of this together with the Enterprise Policy Management Framework (available on codeplex).

I would love to do this (or another) presentation topic for YOUR PASS Chapter as well… so if you’re a chapter leader or a chapter member who is interested in this (or a different) session topic and are willing to do a remote session please let me know and we’ll work on scheduling a date.  I can do either a 30 minute “Short Presentation” or a 60 minute “Feature Presentation”

Thanks!

If you’d like to chat with me about this or anything else (SQL or other) please leave a comment or hit me up on my Twitter: @ColinStasiuk

Disclaimer: The use case I’m going with (checking the uniqueness of a column with a function) I understand can be “solutioned” much better with a unique constraint but this is not to show the best way to do something, rather a tricky little problem with doing it with a check constraint that calls a function.

OK first lets build ourselves a test db and table:

USE master
GO
CREATE DATABASE [FunWithFunctions]
GO
USE FunWithFunctions
GO
CREATE TABLE dbo.tblCustomers
	(
	CustomerID INT NOT NULL IDENTITY (1, 1),
	CustomerName NVARCHAR(50) NULL,
	CustomerEmailAddress NVARCHAR(50) NULL
	)  ON [PRIMARY]
GO
ALTER TABLE dbo.tblCustomers ADD CONSTRAINT
	PK_tblCustomers PRIMARY KEY CLUSTERED
	(
	CustomerID
	) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO

Now we’re going to build our function that returns the count of CustomerIDs that have the same email address:

CREATE FUNCTION dbo.fnEmailAddressUniqueness(@EmailAddress AS NVARCHAR(50))
RETURNS INT
AS
BEGIN
	DECLARE @ReturnValue INT = 0
	SELECT	@ReturnValue = COUNT(CustomerID) FROM tblCustomers WHERE CustomerEmailAddress = @EmailAddress
	RETURN	@ReturnValue
END
GO

OK now we’re going to add a check constraint that uses this function to make sure that there are no other Customers with that email address (CustomerEmailAddress = 0)

ALTER TABLE dbo.tblCustomers ADD CONSTRAINT CK_fnEmailAddressUniqueness CHECK (dbo.fnEmailAddressUniqueness([CustomerEmailAddress])=0)
GO

Fantastic… now this was where I was going to do my insert of 10 rows and show through a profiler trace that my function was going to get called 10 times (once per row) but this happened:

(click to enlarge)

Ummmmm weird…. what happened?

I thought maybe there was something wrong with my function at first so I decided to call the function manually:

SELECT dbo.fnEmailAddressUniqueness('Superman@gmail.com')

That returned 0 (zero) as expected so I was left scratching my head for a while trying to imagine how a check constraint that is checking to make sure a value is 0 would fail (especially on an empty table) then it hit me….

This check constraint that is calling a function is not getting evaluated BEFORE the insert… but DURING/AFTER.

To test this theory I changed the ADD CONSTRAINT statement to this (after I dropped it):

ALTER TABLE dbo.tblCustomers ADD CONSTRAINT CK_fnEmailAddressUniqueness CHECK (dbo.fnEmailAddressUniqueness([CustomerEmailAddress])=1)
GO

And wouldn’t you know it… I could now insert data.

I wasn’t satisfied with just that… I wanted to actually see with my own two eye that it was actually inserting the row, checking the constraint (that calls the function), and removing the row because of the failure.

As dirty as this is, in one SSMS window I did this (using the GO 100000 statement to execute the following statement 100,000 times):

INSERT INTO dbo.tblCustomers(CustomerName, CustomerEmailAddress)
VALUES
('Clark Kent', 'Superman@gmail.com')

And then in a different SSMS window I ran this statement continually:

SELECT * FROM tblCustomers WITH(NOLOCK)

and I did this till the planets aligned and I was able to execute it at the exact split second I needed to capture this:

and then the next time I ran the same SELECT it was gone! (notice the CustomerID 5601)

So I stopped the “GO 100000″ statement that was continually trying to insert that single row and ran the rest of my insert (without the Superman@gmail.com row) and the rest of the data went in fine (with the CustomerID being in the 9000′s even though those IDs really never were actually used”)

Neat/Scary huh?

Anyways I found this to be quite surprising and I figured that I wouldn’t be the only one who would so I thought I’d do a post on it.

Have a great day!

If you’d like to chat with me about this or anything else (SQL or other) please leave a comment or hit me up on my Twitter: @ColinStasiuk

I’ve been working alot with CDC the last little while and found these couple of scripts very useful. These scripts are handy in a DEV type of environment… you should be alot pickier about what you use CDC for but if you’re looking to play around and get your hands dirty then these are the scripts for you.

The first script:

• Checks to see if CDC is enabled
• Enabled CDC
• Creates an “Audit” schema
• Add all tables to CDC
• Create a useful CDC view for each table in the “Audit” schema
• Change the default CDC retention period

The second script tears it all down:

• Drops the views
• Disables the tables from CDC
• Drops the “Audit” Schema
• Disables CDC from the database

FIRST SCRIPT

USE DB_NAME
GO
SET NOCOUNT ON
GO
DECLARE @is_cdc_enabled int
DECLARE @cdc_schema_id int
DECLARE @Role_Name nvarchar(100)
DECLARE @CDC_Retention int
DECLARE @SQL_STMT nvarchar(2000)
DECLARE @RowCount int
DECLARE @CDC_TableName nvarchar(256)
DECLARE @ColumnList nvarchar(2000)
 
SELECT	@Role_Name = NULL
SELECT	@CDC_Retention = 13148730 -- 25 years in minutes
 
/*
**********************************************
		ENABLE AND CONFIGURE CDC
**********************************************
*/
SELECT	@is_cdc_enabled = is_cdc_enabled
FROM	sys.databases
WHERE	[name] = DB_NAME()
 
IF	@is_cdc_enabled != 1
BEGIN
	EXEC sys.sp_cdc_enable_db
END
 
SELECT @SQL_STMT = 'CREATE SCHEMA [Audit] AUTHORIZATION [dbo]'
 
IF NOT EXISTS(SELECT 1 FROM sys.schemas WHERE name = 'Audit')
BEGIN
	EXEC sp_executesql @SQL_STMT
END
 
/*
**********************************************
		ADD TABLES TO CDC
**********************************************
*/
 
SELECT	@cdc_schema_id = [schema_id]
FROM	sys.schemas
WHERE	[name] = 'cdc'
 
SELECT	[name] as 'CDC_TableName'
INTO	#UserTables
FROM	sys.objects
WHERE	type = 'U' and
		is_ms_shipped != 1 and
		[schema_id] != @cdc_schema_id
 
SELECT	@RowCount = COUNT(1)
FROM	#UserTables
 
WHILE	@RowCount != 0
BEGIN
	SELECT TOP 1 @CDC_TableName = CDC_TableName
	FROM	#UserTables
 
	SELECT @SQL_STMT = 'EXEC sys.sp_cdc_enable_table
      @source_schema = ''dbo'',
      @source_name   = ''' + @CDC_TableName + ''',
      @role_name     = null;'
 
	EXEC sp_executesql @SQL_STMT
 
	SELECT	@ColumnList = STUFF(COLUMN_NAME, 1, 1, '')
	FROM	sys.tables t CROSS APPLY  (SELECT	',' + name AS [text()]
									   FROM		sys.columns c
									   WHERE    c.object_id = t.object_id
									   FOR XML PATH('')) o (COLUMN_NAME)
	WHERE OBJECT_NAME(t.[object_id]) = @CDC_TableName
 
	SELECT	@SQL_STMT = 'CREATE VIEW Audit.vw_' + @CDC_TableName +
			' AS     SELECT A.__$start_lsn as ''StartLSN'',
     B.tran_begin_time as ''TransactionStartTime'',
      B.tran_end_time as ''TransactionEndTime'',
      CASE
       WHEN A.__$operation = 1 THEN ''DELETE''
       WHEN A.__$operation = 2 THEN ''INSERT''
       WHEN A.__$operation = 3 THEN ''UPDATE_BEFORE''
       WHEN A.__$operation = 4 THEN ''UPDATE_AFTER''
      END as ''Operation'', ' +
      @ColumnList +
      ' FROM cdc.dbo_' + @CDC_TableName + '_CT A INNER JOIN
  cdc.lsn_time_mapping B ON A.__$start_lsn = B.start_lsn'
 
	EXEC sp_executesql @SQL_STMT
 
	DELETE
	FROM #UserTables
	WHERE	CDC_TableName = @CDC_TableName
 
	SELECT @RowCount = @RowCount - 1
 
END
 
DROP TABLE #UserTables
 
/*
**********************************************
		CHANGE CDC RETENTION
**********************************************
*/
 
EXECUTE sys.sp_cdc_change_job
        @job_type = N'cleanup',
        @retention = @CDC_Retention

SECOND SCRIPT

/*
**********************************************
		TEAR IT DOWN SCRIPT
**********************************************
*/
USE DB_NAME
GO
DECLARE @Audit_schema_id int
DECLARE @RowCount int
DECLARE @ViewName nvarchar(256)
DECLARE @TableName nvarchar(256)
DECLARE @SQL_STMT nvarchar(2000)
 
SELECT	@Audit_schema_id = [schema_id]
FROM	sys.schemas
WHERE	[name] = 'Audit'
 
SELECT	name as 'ViewName'
INTO	#AuditViews
FROM	sys.views
WHERE	schema_id = @Audit_schema_id
 
SELECT	@RowCount = COUNT(1)
FROM	#AuditViews
 
WHILE	@RowCount != 0
BEGIN
	SELECT TOP 1 @ViewName = ViewName
	FROM	#AuditViews
 
	SELECT @SQL_STMT = 'DROP VIEW Audit.' + @ViewName
 
	EXEC sp_executesql @SQL_STMT
 
	DELETE
	FROM #AuditViews
	WHERE	ViewName = @ViewName
 
	SELECT @RowCount = @RowCount - 1
 
END
 
DROP TABLE #AuditViews
 
SELECT	[name] as 'TableName'
INTO	#CDC_TrackedTables
FROM	sys.tables
WHERE	is_tracked_by_cdc = 1
 
SELECT	@RowCount = COUNT(1)
FROM	#CDC_TrackedTables
 
WHILE	@RowCount != 0
BEGIN
	SELECT TOP 1 @TableName = TableName
	FROM	#CDC_TrackedTables
 
	SELECT @SQL_STMT = 'EXEC sys.sp_cdc_disable_table
      @source_schema = ''dbo'',
      @source_name   = ''' + @TableName + ''',
      @capture_instance     = N''All'';'
 
	EXEC sp_executesql @SQL_STMT
 
	DELETE
	FROM #CDC_TrackedTables
	WHERE	TableName = @TableName
 
	SELECT @RowCount = @RowCount - 1
 
END
 
DROP TABLE #CDC_TrackedTables
 
SELECT @SQL_STMT = 'DROP SCHEMA [Audit]'
 
IF EXISTS(SELECT 1 FROM sys.schemas WHERE name = 'Audit')
BEGIN
	EXEC sp_executesql @SQL_STMT
END
 
EXEC sys.sp_cdc_disable_db

There ya go… now you don’t have a reason not to get in there and play around

Enjoy!! (Follow me on Twitter: @ColinStasiuk)

Fellow SQL blogger (and Canadian) Aaron Bertrand broke the news on his blog here

Link to the Service Pack

Link to the bugs that are fixed in SQL Server 2008 SP2

Note (from Aaron re: SP2) : “The Service Pack only includes the fixes that were in SP1 CU 1 through 8.  So if you have already applied CU9 or CU10, I would hold off on deploying the service pack for now, especially if you are relying on any of the fixes in either of those CUs – because there is a chance that you will lose them.”

Now before you get all Service Pack crazy… make sure to slow down, review the changes, and apply the service pack using the same change process you do for any application release.  If you don’t have a change process defined this sounds like a great time to read:

http://benchmarkitconsulting.com/colin-stasiuk/2009/11/11/i-love-fights-that-i-cant-lose-separated-environments-and-security/

Thanks for posting the news Aaron… apparently I need to update where I look for this type of info cause my usual places still don’t have anything posted about it

Enjoy!!

“Gwen Stefani – What you waiting for”

So I happened to have my handy Job Activity Monitor up as I was looking to see if a job I kicked off finished when I noticed a status of “Waiting for Worker Thread”.  I can’t say that I’ve seen this message before so I started looking around as to what else was running at this time.

I had a couple PowerShell jobs running and this job that was “waiting for a worker thread” was a PowerShell job as well.  I called my best friend Google up to see if there was something quick and easy out there to help me figure this one out and I got sent here:

http://support.microsoft.com/kb/306457

specifically…. “Note Microsoft SQL Server 2005 stores the max_worker_thread setting in the syssubsystems table in the msdb system database instead of in the registry. The syssubsystems table can be updated to reflect a non-default max_worker_thread setting.”

So I queried the syssubsystems table in msdb and guess what I found….

PowerShell by default has a max_worker_threads value of 2.

So a quick update to that value (in DEV… you didn’t actually think I would update a system table value in production did you?).  I kicked off more than 2 jobs that called PowerShell scripts and BOOYEAH problem solved.  Now I just bumped this up to 5 because I wanted to do some investigation as to any “gotchas” from messing with this value.

(so far I haven’t found any but I’ll update this post if any come up)

Enjoy!!

Why wouldn’t they just release a PSP?

No not THAT kind of PSP…. PSP is my acronym for “Policy Service Pack”

Policy Based Management is/was/should be the replacement for the Best Practices Analyzer so why now are we bringing the BPA back?  To me it would just make more sense to release some additional policies to add to the 50+ “Best Practice” policies that already are included with SQL Server 2008.

Now granted (as mentioned above) I have yet to install and give it a test drive so perhaps I’m missing something but in my opinion releasing this tool will affect the adoption rate of DBAs using Policy Based Management.

I’m downloading and installing now…. follow up blog to come

Enjoy!!

http://www.eventbrite.com/event/686883487

Please be sure to not only click the “Add to my calendar” but also the “Register” button so that we can plan accordingly for food and drinks. 

Date:  July 7th 2010
Time: 5:00 pm – 7:00 pm
Location: Stanley A. Milner library
Map: 7 Sir Winston Churchill Square
Meeting Room: Centennial Room – Basement
Speaker: Brent Ozar
Topic: Virtualization and Magicians: Dealing with Virtual SQL Server

Session Abstract:

Virtualization and Magicians: Dealing with Virtual SQL Server

• How to configure CPU, memory and storage for virtual environments
• How to benchmark your servers and make sure they’ll handle your loads
• Common pitfalls like antivirus definition downloads that can cripple your servers
• What to watch for after V-day

Presenter Information:  Brent Ozar

Brent is a SQL Server Domain Expert with Quest Software. Brent has a decade of broad IT experience, performing systems administration and project management before moving into database administration. In his current role, Brent specializes in performance tuning, disaster recovery and automating SQL Server management. Previously, Brent spent 2 years at Southern Wine & Spirits, a Miami-based wine & spirits distributor.

Brent has experience conducting training sessions, has written several technical articles, and blogs prolifically at http://www.BrentOzar.com. He’s currently writing SQL Server Internals and Troubleshooting for Wiley/Wrox along with Christian Bolton, and Justin Langford.  He’s Editor-in-Chief at SQLServerPedia.com, where he also records video podcasts.

Agenda:
5:00 pm – Pizza and Socializing
5:30 pm – Sponsor Presentation
5:45 pm – Feature Presentation
7:00 pm – Wrap Up and Draws

If you haven’t signed up already at EDMPASS.com please do so now to receive meeting notifications, news, and updates from EDMPASS.

Hope to see you there.

Enjoy!!

http://www.eventbrite.com/event/623637316

Date: May 26th 2010
Time: 5:00 pm – 7:00 pm
Location: Stanley A. Milner library
Map: 7 Sir Winston Churchill Square
Meeting Room: Centennial Room – BASEMENT
Speaker: Colin Stasiuk
Topic: Policy Based Management… not JUST for SQL Server 2008

Session Abstract:

Policy Based Management… not JUST for SQL Server 2008

Colin Stasiuk is an MCP, MCTS SQL 2005/2008, MCITP DBDEV, and MCITP DBA. Currently, he is an independent consultant contracted to Vantix Systems and working for the Government of Alberta.

Colin is an accomplished Microsoft SQL Server DBA who has been working with SQL Server since 1996. He is the founder of Benchmark IT Consulting and is always willing to lend a hand with questions in many SQL Server community forums and via Twitter (http://twitter.com/BenchmarkIT) . His specialties include SQL Server Administration, Performance Tuning, Security, Monitoring, Best Practice / Standards, Upgrades, and Consolidation.

Colin is a proud PASS member, President of EDMPASS, and has recently co-authored a book on SQL Server 2008 Policy Based Management.

Agenda:
5:00 pm – Pizza and Socializing
5:30 pm – Sponsor Presentation
5:45 pm – Feature Presentation
7:00 pm – Wrap Up and Draws

If you haven’t signed up already at EDMPASS.com please do so now to receive meeting notifications, news, and updates from EDMPASS.

Hope to see you there.

Enjoy!!

We had our most successful EDMPASS meeting ever last night.  We were lucky enough to get (newly appointed MVP) Brent Ozar via Live Meeting as our feature presenter.  The session was titled “Hit the Ground Running with SQL Server 2008″ and it was a great presentation on the Central Management Server, Policy Based Management, and the Resource Governor. 

I jokingly refer to Brent Ozar as my “Mr Miyagi of the SQL Server Community”… when I first decided to start blogging and get more involved in the community he was always more then willing to lend a hand and opinion on how best to approach things and his advice has always proven to be invaluable.

I was shocked this morning when I heard that Brent Ozar is NOW an MVP… I always thought he was one as he’s been one of the many great leaders in the community so I guess Microsoft was just a little behind the curve but at least they got it right now

My congratz also go out to my friends Jeremiah Peschka and Tim Ford as well as to all the new MVPs… keep up the good work everyone!

Enjoy!!