Sunday, December 25, 2011

New T-SQL Features in SQL Server 2012

 

In every version of SQL Server new T-SQL features are introduced. These are new T-SQL features of SQL Server 2012.

  • Sequences
  • Function
    • String function CONCAT,FORMAT
    • Logical function CHOOSE,IIF
    • Date & time function
      • DATEFROMPARTS
      • DATETIMEFROMPARTS
      • DATETIME2FROMPARTS
      • DATETIMEOFFSETFROMPARTS
      • SMALLDATETIMEFROMPARTS
      • TIMEFROMPARTS
      • EOMONTH
    • Conversion function
      • PARSE
      • TRY_CONVERT
      • TRY_PARSE
  • Paging Data
  • Lag & Lead
  • Exception handling
  • WithResultSets

Friday, December 23, 2011

Sample Databases for SQL Server 2012 RC0

 

Sample databases dedicated to SQL Server 2012 RC0 are released. AdventureWorks2008R2_Data.mdf and AdventureWorksDWDenali_Data.mdf are those files. You need to attach these mdf files to your SQL Server instance.

Download these sample data files from here.

Tuesday, December 20, 2011

New Express Edition : LocalDB

New to the Express family, LocalDB is a lightweight version of Express that has all its programmability features, yet runs in user mode and has a fast, zero-configuration installation and short list of pre-requisites. Use this if you need a simple way to create and work with databases from code. It can be bundled with Visual Studio, other Database Development tools, or embedded with an application that needs local databases.

Try it here today!

Monday, December 19, 2011

Drop a Database by Closing Existing Connections using SSMS or T-SQL

 

Dropping database from SQL Server is not a major task. However, it can be painful if that database is being used at time of dropping it. Read this FAQ from www.sql-server-performance.com

Wednesday, December 14, 2011

Two SPIDs in sp_who2

 

sp_who2 is function you can use to identify who (Login) is running at what (DBName, command) from where (SPID & Host) as you can see in the following image.

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If you look closely, you will see that there are two SPID columns with same values. By looking at them, they are same So let us see the coding of this.

image

So you would see that SPID column is convert(char(5),spid) so why on earth same column twice.

Just see the comment after second SPID.

Handy extra for right-scrolling users.

Do you agree. I am not Smile .

Wednesday, November 30, 2011

TechInsights 2011

I was a speaker at TechInsights 2011 which was held in Malaysia at Monash University Kuala Lampur.

Well, this is my first appearance out side Sri Lanka and was a great experience.

I did two sessions 1. CDC for SCD and 2. Resource Governor. To be honest, first session was not much participated second one was far better.

Here are few photos of the sessions.

TI2TI3

TI1TI4

Here are Presentations and Samples

Saturday, November 19, 2011

SQL Server 2012 RC0

SQL Server 2012 Release Candidate 0 is now available for download. SQL Server 2012 RC0 (previously code-named Denali) includes several new capabilities (most of which are related to the release’s new features) that weren’t available in SQL Server Denali CTP3, including the following:

  • AlwaysOn—SQL Server 2012 RC0 offers multiple readable secondaries in AlwaysOn, which lets you better distribute backup and reporting workloads, and it now supports the FileTable and FILESTREAM data types.
  • Resource Governor—According the SQL Server Team Blog, SQL Server 2012’s Resource Governor includes several new capabilities, including support for 64 resource pools, enhanced CPU usage controls, and enhanced resource allocation.
  • Cloud Computing—SQL Server Management Studio (SSMS) now supports snapshot backups to Windows Azure.
  • Data Quality Services and Master Data Services—This release provides Change Data Capture (CDC) support for Oracle.
  • Power View—The data visualization tool includes new features with SQL Server 2012 RC0.

For more information about the upcoming release of SQL Server, see Microsoft’s SQL Server 2012 page. You can download SQL Server 2012 RC0 here.

Sunday, November 13, 2011

Combining Columns Ignoring Null Columns

Let’s start with an example.

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You will see that MiddleName column has NULL values. If you want to combine all four columns and display them in one column you will write following query.

image

Result is,

image

You will realize the obvious problems from the above result set. To avoid this what you should is, use the ISNULL function.

image

Though the above will solve your problem, as a developer you need to keep an eye on nullability of the column.

With Denali, you have a new function called CONCAT.

image

And the result is,

image

which is what we were looking for.

Next question is, how about the performance.

To answer that I will display query execution plans for two queries, one with CONCAT and the other with ISNULL function.

image

So there is no additional cost with the new function.

Saturday, November 5, 2011

SQL Server 2012 Editions

SQL Server 2012 users will experience new SQL Server editions called Business Intelligence  to the addition of existing editions, Enterprise, Standard, Web , Developer, Express and Evolution.

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image

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If you wish for more news about editions and licensing click it here.

Monday, October 31, 2011

TRY_CONVERT

I am sure you would have used CONVERT function many times.

image

If you see the above data set, last date value is an invalid date. If you are integrating with legacy systems, you will these types of records.

They you might need to convert these into a date time value. Naturally, you will use, CONVERT function.

image

But it will fail.

image

In Denali or SQL Server 2012 (as per CTP3) you have new function called TRY_CONVERT.

image

With this new function, you won’t get the error as well as you will be able to find out the errors as well.

Following query will return all the rows where you have an invalid date value.

image

You can use this for other data types as well.

Download the code from here

Sunday, October 16, 2011

SQL Server 2008 SP3 is now available!

Microsoft SQL Server Sustained Engineering group is pleased to announce the release of SQL Server 2008 Service Pack 3 (SP3). Both the Service Pack and Feature Pack updates are available for download on the Microsoft Download Center. As part of our continued commitment to software excellence for our customers, this upgrade is free and doesn’t require an additional service contract.

Download it from here

Friday, September 30, 2011

Failing of alter Table statement

Replication Agent will fail when attempting to alter a column in the publisher which is part of an index.

Here is the faq of mine.

Wednesday, August 31, 2011

දත්ත මූලිකයන්හි සිංහලෙන් දත්ත ගබඩා කරමු

මෙය මවිසින් ලියන ලද දෙවැනි ලිපියයි.

මෑතකදී, විශ්ව විද්‍යාලයක සිසුන් පිරිසක් තම පාඨමාලවේ පර්යේෂන වියාපෘතියකට ශ්‍රි ලංකා පොලීසිය සදහා ලැබෙන සුළු අපරාධ විශ්ලේශණය කිරීම තෝරා ගෙන තිබුනි. ඒ සදහා ඔවුන් සිංහලෙන් දත්ත ගබඩා කිරිමට තෝරා ගෙන තිබිනි. එයට මූලික හේතුව වී තිබුනේ, ලැබෙන දත්ත භාවිතා කරන අයට ඉංග්‍රීසි භාවිතයට වඩා සිංහල පහසු නිසාය. බොහෝ ශ්‍රි ලංකාවේ රාජ්‍ය ආයතයන් හි මෙම තත්වය ඇති බැවින්, ඒ පිළිබදව කිසියම් විස්තරයක් කිරීම මෙම ලිපියෙහි අරමුණයි.

දත්ත මූලිකයන්හි සිංහලෙන් දත්ත ගබඩා කරමු

Tuesday, August 30, 2011

Change the case of the Logical Name of a SQL Server Database

When you create a database, by default data file and log file will be added to the database. For logical name it will be, Databasename_log. Let us say you want to change it to Database_Log (where L is in upper case).

ALTER DATABASE [TailLog]
MODIFY FILE (NAME=N'TailLog_log', NEWNAME=N'TailLog_Log')
GO

Then you will get an following error.

Msg 1828, Level 16, State 3, Line 1
The logical file name "TailLog_Log" is already in use. Choose a different name.

Let us try to do this from the SSMS.

image

So basically you are not allow to do this.

What you have to do is, first set it to another name.

ALTER DATABASE [TailLog]
MODIFY FILE (NAME=N'TailLog_log', NEWNAME=N'TailLog_LogTemp')
GO

The file name 'TailLog_LogTemp' has been set.

Then change it back to TailLog_Log so that you can achieve your target.

ALTER DATABASE [TailLog]
MODIFY FILE (NAME=N'TailLog_LogTemp', NEWNAME=N'TailLog_Log')
GO

Saturday, August 27, 2011

Disk Usage Report in SSMS

Reports in SSMS are very helpful when monitoring SQL Server. But today I encounter an issue with one of the reports, which is Disk Usage Report.

 

imageimage

Above is the Transaction Log space usage report taken for same database but for different times. Actually, second one was after taking a log backup. After seeing this report my immediate reaction was log backup has not cleared the log. So I ran another log backup and results are similar. But when you analyze these graphs carefully you would see that in the first graph, Green is Used and in the second Green is Unused and Blue is vice-versa. (Oops).

I did few more research into this to find out the tipping point and this is happening after 50% percent. See the image below.

image

image

image

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Now it is 50-50 and next one is,

image

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You can clearly see the change. I verified this is the same behavior in SQL Server 2008 R2 as well.

Thursday, August 11, 2011

Using $IDENTITY function

You may have used many different Identity functions like SCOPE_IDENTITY(), @@IDENTITY etc. but have you used $IDENTITY function.

Let us say you have a table where identity property is set in one of the columns.

image

if you run the following query,

image

Following is the result,

image

This means, you don’t have to explicitly mention the identity column instead you can use $IDENTITY.  You can use this for all aggregations ( AVG ($IDENTITY), MAX($IDENTITY) etc) as well as in grouping columns.

Tuesday, August 9, 2011

පූර්ණ කාලීන දත්ත මූලික කළමනාකරුවන් (DBA) අවශ්‍ය ඇයි? (si-LK)

මෙය මා විසින් ලියන ලද පළමු සිංහල blog සටහනයි. බොහෝ කලක පටන් පැවති අදහසක් "දැවන්ත" කාර්යයකින් පසු මෙසේ සටහනක් බවට පත්විය. මේ වෙනුවෙන් මට සහාය වු, Fiqriට මගේ ස්තුතිය.

පූර්ණ කාලීන දත්ත මූලික කළමනාකරුවන් (DBA) අවශ්‍ය ඇයි? (si-LK)

Sunday, August 7, 2011

@Refresh Colombo

This was my first presentation in public outside Microsoft technologies. Presentation was on MongoDB which Susantha and myslef are doing quite a bit of R&D lately.

Our presentation went well and had few questions from the audience which was just over 1000.

Entire event was covered by adaderana

You can view all the pictures at facebook and samples are available in my skydrive.

Saturday, July 30, 2011

Function for End of Month

Did you have a requirement  of getting last date of the month by passing any date. I can remember I had this requirement during SQL Server 2000 days, in a HR system.

If you search for this in Google followings are the results.

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There are around 2,350,000 results!. In these results, there you might they have used DATEDIFF and DATEADD functions.

With Denali CTP3 (not sure whether this was there in CTP1) new function called EOMonth is included. Now it is simply matter of passing date.

You can see the a syntax in the following image. Point to note here is there is no execution plan differences between this version and the previous. So only difference will be the usability,

image

Wednesday, July 20, 2011

MongoDB @Refresh Colombo

This is my first presetion on MongoDB in public. I did few presentation in office before this on same subject and written two articles to office Magazine. One of those articles won the best article award. So let's see how this will go @RefreshColombo

Friday, July 15, 2011

Are You Using SSMS effectively ?

SQL Server Management Studio is an essential tool for DBAs and developers. But are you using it effectively? In this article, I will try examine a few tips and techniques which could well boost your efficiency using SSMS.

Read the entire article here

SQL Server 2008 R2 SP1 Released

SQL Server 2008 R2 SP1 release was not much highlighted since Denali CTP3 is making all the headlines.

untitled

Microsoft SQL Server 2008 R2 Service Pack 1 delivers hotfix solutions from SQL Server 2008 CU 1 to CU 6 in addition to resolving to customer requests with key security and supportability issues. SQL Server 2008 R2 SP1 has also seen 8% less bugs requiring resolution within the Service Pack scope when compared with SQL Server 2008 SP1.

Related Links:

·        Download SQL Server 2008 R2 SP1

·        Download SQL Server 2008 R2 SP1 Express

·        Download SQL Server 2008 R2 SP1 Feature Packs

·        Knowledge Base Article for Microsoft SQL Server 2008 R2 SP1


Thursday, July 14, 2011

Denali CTP3 Now Available

Much anticipated Denali CTP3 is now available for download from Microsoft. This is the third Community Technology Preview of codenamed Denali.

According to Microsoft, SQL Server 2012 codenamed Denali will enable customers to:
“•Deliver required uptime and data protection with AlwaysOn
•Gain breakthrough & predictable performance with Project Apollo
•Help enable security and compliance with new User-defined Roles and Default Schema for Groups
•Enable rapid data discovery for deeper insights across the organization with Project Crescent
•Ensure more credible, consistent data with SSIS improvements, a Master Data Services add-in for Excel, and new Data Quality Services
•Optimize IT and developer productivity across server and cloud with Data-tier Application Component (DAC) parity with SQL Azure and SQL Server Developer Tools code name “Juneau” for a unified dev experience across database, BI, and cloud functions.”

Though there is no official yet, it is believe that this version of SQL Server will be named as 2012 not as 2011 as said some time back. Nice way of postponing the release!

SQL Server 2012 Codenamed Denali CTP3 is available for download here.

Friday, June 24, 2011

How long does it take to fix a bug

In the development cycle, it is needless to less we all in some part of our carrier, have injected  bugs in different scale. However, when we were told it is a bug, I am sure most of you try to fix it or prioritize it to fix it.

But can you imagine, if there is a bug in SQL Server for more than 5 years, ranging three SQL Server Products (SQL Server 2005, SQL Server 2008 and R2).

This bug is in CTE.

Now CTE was introduced primarily to support recursive queries.

Let’s say I have a table and data like this.

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So I have a hierarchy as following.

image

Let’s assume that, you need to retrieve, only two levels starting from Richard, here is the query you should use.

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so number of levels are handled by , MAXRECURSION = 2 option. In this of course, you will get the result but also and ERROR!!!,

yes, error says,

Msg 530, Level 16, State 1, Line 1
The statement terminated. The maximum recursion 2 has been exhausted before statement completion.

You can say that since it giving the correct result, what is the big deal about this. But the problem here is, since it is a Level 16 error, if you are using this inside of your code, your code will throw an exception.

You have a workaround which I have given in my sample code at the end of this post.

Now this error first appeared in SQL Server 2005 and Microsoft has make sure that they don’t fix this so you can see the same bug in SQL Server 2008 and in R2. I got to know that this was initially reported in 2002 when SQL Server 2005 CTP was released. So it is nine years now.

To confirm the stuff, I checked this in Denali CTP1. Guess what, still this issue in the backlog.

error.cg

Download sample code from here

Monday, June 13, 2011

Altering a Column Which has a Default Constraint

If you are altering a column with default column, you need to drop it. but the problem will be if you created a default constraint without explicitly specifying  constraint name. Here is a faq from me.

Thursday, June 2, 2011

xp_msver

xp_msver is a extended stored procedure, to get some valuable information in SQL Server.

EXEC master.dbo.xp_msver

Will return,

clip_image002

Most important parameters that I can think of is, ProductVersion (not a big deal since you can get this from ServerProperty function), ProcessorCount, Physical Memory.

Next question is, why you would need this?

Let’s say, you need to set the Maximum Degree of the Parallelism (MAXDOP) as a function of number of Processor count. For example, some DBAs want to have MAXDOP to, ProcessorCount – 2.

 

image-

Similarly you can set the memory allocation as well.

Download relevant script from here

Tuesday, May 31, 2011

Wednesday, May 25, 2011

Whether to use UNION or OR in SQL Server Queries

I got this idea of writing this article while reading the IBM Database a.k.a. DB2 magazine.

Tuesday, April 26, 2011

Capturing Time-Out Procedures using Extended Events

Due to various reasons, your procedures will fail after time out period elapsed.

image

 

But with the above generic error message, it is difficult to find out which procedure was failed.

Obvious way to find out timing out procedures are to debug your code. However, sometimes you might not be able to create this issue in your environments, since time-out error might depend on the environment setting or environment data.

So let us create a procedure which will time out.

image

Since this proc is having a delay for 20 hrs, it will obviously will fail with time out.

Let us call this procedure from C# application.

image

Though profiler can be used to capture this, running profiler may decrease your system performance. Microsoft introduced Extended Events to SQL Server, calming it is a light weight monitoring

In extended event, there is an event type called Event pairing, shows incomplete events. There are some events which are pairs such as lock acquired and lock released and from this event type we can capture incomplete events.

In our scenario, paired events are sp_statement_starting and sp_statement_completed and in case of a timing out, sp_statement_Completed event will not be completed.

You can create a extended event like following/

image

 

Then we can capture the event by running following query.

image

 

This result will give you

image

 

This means, though there are 11127 matched events, there is one orphan event which is what we are after.

If you expand the XML, it will give you the database id and the object id from which can find the culprit.

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Interesting thing here is, sql_text is shown as Unable to retrieve SQL text, but if you execute this proc in SSMS, you will see the relevant proc in this XML it self.