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  • SQL SERVER – Move Database Files MDF and LDF to Another Location

    - by pinaldave
    When a novice DBA or Developer create a database they use SQL Server Management Studio to create new database. Additionally, the T-SQL script to create a database is very easy as well. You can just write CREATE DATABASE DatabaseName and it will create new database for you. The point to remember here is that it will create the database at the default location specified for SQL Server Instance (this default instance can be changed and we will see that in future blog posts). Now, once the database goes in production it will start to grow. It is not common to keep the Database on the same location where OS is installed. Usually Database files are on SAN, Separate Disk Array or on SSDs. This is done usually for performance reason and manageability perspective. Now the challenges comes up when database which was installed at not preferred default location and needs to move to a different location. Here is the quick tutorial how you can do it. Let us assume we have two folders loc1 and loc2. We want to move database files from loc1 to loc2. USE MASTER; GO -- Take database in single user mode -- if you are facing errors -- This may terminate your active transactions for database ALTER DATABASE TestDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE; GO -- Detach DB EXEC MASTER.dbo.sp_detach_db @dbname = N'TestDB' GO Now move the files from loc1 to loc2. You can now reattach the files with new locations. -- Move MDF File from Loc1 to Loc 2 -- Re-Attached DB CREATE DATABASE [TestDB] ON ( FILENAME = N'F:\loc2\TestDB.mdf' ), ( FILENAME = N'F:\loc2\TestDB_log.ldf' ) FOR ATTACH GO Well, we are done. There is little warning here for you: If you do ROLLBACK IMMEDIATE you may terminate your active transactions so do not use it randomly. Do it if you are confident that they are not needed or due to any reason there is a connection to the database which you are not able to kill manually after review. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Backup and Restore, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Backup SQL databases to Box or SkyDrive

    - by Pinal Dave
    To ensure your SQL Server or Azure databases remain safe, you should backup your databases periodically. And it is important to store the backups in a reliable location. Microsoft SkyDrive currently offers 7GB free, Box offers 5GB free – both are reliable and it is simple to send your backups there. SQLBackupAndFTP in it’s latest version 9 added the option to backup to SkyDrive and Box ( in addition to local/network folder, NAS drive, FTP, Dropbox, Google Drive and Amazon S3). Just select the databases that you’d like to backup and select to store the backups in SkyDrive or Box. Below I will show you how to do it in details Select databases to backup First connect to your SQL Server or Azure Sql Database. Then select the databases you’d like to backup. Connect to SkyDrive or Box cloud If you have a free version of SQLBackupAndFTP Box destination is included, but SkyDrive destination will be disabled as it is available in the Standard version or above. Click “Try now” to get 30 days trial on all options On the “SkyDrive Settings” form you’ll need to authorize SQLBackupAndFTP to access your SkyDrive. Click “Authorize…” to open SkyDrive authorization page in your browser, sign in your to SkyDrive account and click at “Allow” . On the next page you will see the field with authorization code. Copy it to the clipboard. Box operation is just the same. After that return to SQLBackupAndFTP, paste the authorization code and click “OK” . After you are authorized, you can enter the path to a backup folder. SQLBackupAndFTP will create the folder if it does not exist. That’s all what has to be done to backup to SkyDrive or Box cloud.  You can now click on “Run Now” button to test this job. Conclusion Whatever is your preference for storing SQL backups, it is easy with SQLBackupAndFTP. Note that at the time of this writing they are running a very rare promotion on volume licenses: 5–9 licenses: 20% off 10–19 licenses: 35% off more than 20 licenses: 50% off Please let me know your favorite options for storing the backups. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • SQLAuthority News – Monthly Roundup of Best SQL Posts

    - by pinaldave
    After receiving lots of requests from different readers for long time I have decided to write first monthly round up. If all of you like it I will continue writing the same every month. In fact, I really like the idea as I was able to go back and read all of my posts written in this month. This month was started with answering one of the most common question asked me to about What is Adventureworks? Many of you know the answer but to the surprise more number of the reader did not know the answer. There were few extra blog post which were in the same line as following. SQL SERVER – The Difference between Dual Core vs. Core 2 Duo SQLAuthority News – Wireless Router Security and Attached Devices – Complex Password SQL SERVER – DATE and TIME in SQL Server 2008 DMVs are also one of the most handy tools available in SQL Server, I have written following blog post where I have used DMV in scripts. SQL SERVER – Get Latest SQL Query for Sessions – DMV SQL SERVER – Find Most Expensive Queries Using DMV SQL SERVER – List All the DMV and DMF on Server I was able to write two follow-up of my earlier series where I was finding the size of the indexes using different SQL Scripts. And in fact one of the article Powershell is used as well. This was my very first attempt to use Powershell. SQL SERVER – Size of Index Table for Each Index – Solution 2 SQL SERVER – Size of Index Table for Each Index – Solution 3 – Powershell SQL SERVER – Four Posts on Removing the Bookmark Lookup – Key Lookup Without realizing I wrote series of the blog post on disabled index here is its complete list. I plan to write one more follow-up list on the same. SQL SERVER – Disable Clustered Index and Data Insert SQL SERVER – Understanding ALTER INDEX ALL REBUILD with Disabled Clustered Index SQL SERVER – Disabled Index and Update Statistics Two special post which I found very interesting to write are as following. SQL SERVER – SHRINKFILE and TRUNCATE Log File in SQL Server 2008 SQL SERVER – Simple Example of Snapshot Isolation – Reduce the Blocking Transactions In personal adventures, I won the Community Impact Award for Last Year from Microsoft. Please leave your comment about how can I improve this round up or what more details I should include in the same. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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  • SQL SERVER – Solution – Puzzle – Challenge – Error While Converting Money to Decimal

    - by pinaldave
    Earlier I had posted quick puzzle and I had received wonderful response to the same. Today we will go over the solution. The puzzle was posted here: SQL SERVER – Puzzle – Challenge – Error While Converting Money to Decimal Run following code in SSMS: DECLARE @mymoney MONEY; SET @mymoney = 12345.67; SELECT CAST(@mymoney AS DECIMAL(5,2)) MoneyInt; GO Above code will give following error: Msg 8115, Level 16, State 8, Line 3 Arithmetic overflow error converting money to data type numeric. Why and what is the solution? Solution is as following: DECLARE @mymoney MONEY; SET @mymoney = 12345.67; SELECT CAST(@mymoney AS DECIMAL(7,2)) MoneyInt; GO There were more than 20 valid answers. Here is the reason. Decimal data type is defined as Decimal (Precision, Scale), in other words Decimal (Total digits, Digits after decimal point).. Precision includes Scale. So Decimal (5,2) actually means, we can have 3 digits before decimal and 2 digits after decimal. To accommodate 12345.67 one need higher precision. The correct answer would be DECIMAL (7,2) as it can hold all the seven digits. Here are the list of the experts who have got correct answer and I encourage all of you to read the same over hear. Fbncs Piyush Srivastava Dheeraj Abhishek Anil Gurjar Keval Patel Rajan Patel Himanshu Patel Anurodh Srivastava aasim abdullah Paulo R. Pereira Chintak Chhapia Scott Humphrey Alok Chandra Shahi Imran Mohammed SHIVSHANKER The very first answer was provided by Fbncs and Dheeraj had very interesting comment. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, Readers Contribution, Readers Question, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQLAuthority News – 18 Seconds of Fame – My PASS Experience

    - by pinaldave
    Happy Holidays to All of YOU! Life is full of little and happy surprises. I think Christmas and Santa are based on it. I just received very interesting email earlier today, I had no idea about it. Earlier this year, I had visited Seattle to attend SQLPASS – read the complete summary over here: SQLAuthority News – SQLPASS Nov 8-11, 2010-Seattle – An Alternative Look at Experience. While I was walking down, someone has stopped me and asked if they can talk to me for 15 seconds, I said yes and they had shot quick movie with mobile. The conversation was very quick and I had forgotten about it. Today I received email from one of the blog reader about it being on YouTube. Honestly, I did not know if this was ever going to be on YouTube. I am surprised and thrilled. Watch my 18 seconds fame movie. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: About Me, Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, T SQL, Technology

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  • SQL SERVER – Reduce the Virtual Log Files (VLFs) from LDF file

    - by pinaldave
    Earlier, I wrote a quite note on SQL SERVER – Detect Virtual Log Files (VLF) in LDF. Because of this I got responses suggesting too many VLFs are bad for log file. This prompts to a simple question: “How many is ‘too many’ VLFs?” I suggest that you go and read an article written by Kimberly over here. I am sure that you are going to have a clear understanding of what a good number for your VLFs is from that article. If you have lots of VLFs, you can reduce them right away using the following method: (I am just attempting to write a working script over here.) USE AdventureWorks GO BACKUP LOG AdventureWorks TO DISK='d:\adtlog.bak' GO -- Get Logical file name of the log file sp_helpfile GO DBCC SHRINKFILE(AdventureWorks_Log,TRUNCATEONLY) GO ALTER DATABASE AdventureWorks MODIFY FILE (NAME = AdventureWorks_Log,SIZE = 1GB) GO DBCC LOGINFO GO Again, here I have assumed that your initial log size is 1 GB, but in reality you should select the number based on your own ideal size of the log file. If your log file grows to 10 GB every day, you may want to put the value as 10 GB. For accuracy, read what Kimberly’s original article says over here. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – 2011 – SEQUENCE is not IDENTITY

    - by pinaldave
    Yesterday I posted blog post on the subject SQL SERVER – 2011 – Introduction to SEQUENCE – Simple Example of SEQUENCE and I received comment where user was not clear about difference between SEQUENCE and IDENTITY. The reality is that SEQUENCE not like IDENTITY. There is very clear difference between them. Identity is about single column. Sequence is always incrementing and it is not dependent on any table. Here is the quick example of the same. USE AdventureWorks2008R2 GO CREATE SEQUENCE [Seq] AS [int] START WITH 1 INCREMENT BY 1 MAXVALUE 20000 GO -- Run five times SELECT NEXT VALUE FOR Seq AS SeqNumber; SELECT NEXT VALUE FOR Seq AS SeqNumber; SELECT NEXT VALUE FOR Seq AS SeqNumber; SELECT NEXT VALUE FOR Seq AS SeqNumber; SELECT NEXT VALUE FOR Seq AS SeqNumber; GO -- Clean Up DROP SEQUENCE [Seq] GO Here is the resultset. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Removing Leading Zeros From Column in Table – Part 2

    - by pinaldave
    Earlier I wrote a blog post about Remvoing Leading Zeros from Column In Table. It was a great co-incident that my friend Madhivanan (no need of introduction for him) also post a similar article over on BeyondRelational.com. I strongly suggest to read his blog as well as he has suggested some cool solutions to the same problem. On original blog post asked two questions 1) if my sample for testing is correct and 2) If there is any better method to achieve the same. The response was amazing. I am proud on our SQL Community that we all keep on improving on each other’s contribution. There are some really good suggestions as a comment. Let us go over them right now. Improving the ResultSet I had missed including all zeros in my sample set which was an overlook. Here is the new sample which includes all zero values as well. USE tempdb GO -- Create sample table CREATE TABLE Table1 (Col1 VARCHAR(100)) INSERT INTO Table1 (Col1) SELECT '0001' UNION ALL SELECT '000100' UNION ALL SELECT '100100' UNION ALL SELECT '000 0001' UNION ALL SELECT '00.001' UNION ALL SELECT '01.001' UNION ALL SELECT '0000' GO Now let us go over some of the fantastic solutions which we have received. Response from Rainmaker SELECT CASE PATINDEX('%[^0 ]%', Col1 + ' ‘') WHEN 0 THEN '' ELSE SUBSTRING(Col1, PATINDEX('%[^0 ]%', Col1 + ' '), LEN(Col1)) END FROM Table1 Response from Harsh Solution 1 SELECT SUBSTRING(Col1, PATINDEX('%[^0 ]%', Col1 + 'a'), LEN(Col1)) FROM Table1 Response from Harsh Solution 2 SELECT RIGHT(Col1, LEN(Col1)+1 -PATINDEX('%[^0 ]%', Col1 + 'a' )) FROM Table1 Response from lucazav SELECT T.Col1 , label = CAST( CAST(REPLACE(T.Col1, ' ', '') AS FLOAT) AS VARCHAR(10)) FROM Table1 AS T Response from iamAkashSingh SELECT REPLACE(LTRIM(REPLACE(col1,'0',' ')),' ','0') FROM table1 Here is the resultset of above scripts. It will remove any leading zero or space and will display the number accordingly. If you believe there is a better solution, please leave a comment. I am just glad to see so many various responses and all of them teach us something new. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQLAuthority News – #TechEDIn – TechEd India 2012 – Things to Do and Explore for SQL Enthusiast

    - by pinaldave
    TechEd India 2012 is just 48 hours away and I have been receiving lots of requests regarding how SQL enthusiasts can maximize their time they’ll be spending at TechEd India 2012. Trust me – TechEd is the biggest Tech Event in India and it is much larger in magnitude than we can imagine. There are plenty of tracks there and lots of things to do. Honestly, we need clone ourselves multiple times to completely cover the event. However, I am going to talk about SQL enthusiasts only right now. In this post, I’ll share a few things they can do in this big event. But before I start talking about specific things, there is one thing which is a must – Keynote. There are amazing Keynotes planned every single day at TechEd India 2012. One should not miss them at all. Social Media I am a big believer of the social media. I am everywhere - Twitter, Facebook, LinkedIn and GPlus. I suggest you follow the tag #TechEdIn as well as contribute at the healthy conversation going on right now. You may want to follow a few of the SQL Server enthusiasts who are also attending events like TechEd India. This way, you will know where they are and you can contribute along with them. For a good start, you can follow all the speakers who are presenting at the event. I have linked all the speakers’ names with their respective Twitter accounts. Networking Do not stop meeting new people. Introduce yourself. Catch the speakers after their sessions. Meet other SQL experts and discuss SQL as well as life aside SQL. The best way to start the communication is to talk about something new. Here are a few lines I usually use when I have to break the ice: SQL Server 2012 is just released and I have installed it. How many SQL Server sessions are you going to attend? I am going to attend _________ I am a big fan of SQL Server. Sessions Agenda Day 1 T-SQL Rediscovered with SQL Server 2012 - Jacob Sebastian Catapult your data with SQL Server 2012 integration services - Praveen Srivatsa Processing Big Data with SQL Server 2012 and Hadoop  - Stephan Forte SQL Server Misconceptions and Resolution – A Practical Perspective – Pinal Dave and Vinod Kumar Securing with ContainedDB in SQL Server 2012  - Pranab Majumdar Agenda Day 2 Hand-on-Lab – Exploring Power View with SQL Server 2012 – Ravi S. Maniam Hand-on-Lab - SQL Server 2012 – AlwaysOn Availability Groups  - Amit Ganguli Agenda Day 3 Peeling SQL Server like an Onion: Internals Debunked  - Vinod Kumar Speed Up! – Parallel Processes and Unparalleled Performance  - Pinal Dave Keeping Your Database Available – ‘AlwaysOn’  - Balmukund Lakhani Lesser Known Facts of SQL Server Backup and Restore  - Amit Banerjee Top five reasons why you want SQL Server 2012 BI - Praveen Srivatsa Product Booth and Event Partners There will be a dedicated SQL Server booth at the event. I suggest you stop by there and do communication with SQL Server Experts. Additionally there will be booths of various event partners. Stop by their booth and see if they have a product which can help your career. I know that Pluralsight has recently released my course on their online learning site and if that interests you, you can talk about the subject with them. Bring Your Camera Make a list of the people you want to meet. Follow them on Twitter or send them an email and know their location. Introduce yourself, meet them and have your conversation. Do not forget to take a photo with them and later on, share the photo on social media. It would be nice to send an email to everyone with attached high resolution images if you have their email address. After-hours parties After-hours parties are not always about eating and meeting friends but sometimes, they are very informative. Last time I ended up meeting an SQL expert, and we end up talking for long hours on various aspects of SQL Server. After 4 hours, we figured out that he stays in the same apartment complex as mine and since we have had an excellent friendship, he has then become our family friend. So, my advice is that you start to seek out who is meeting where in the evening and see if you can get invited to the parties. Make new friends but never lose mutual respect by doing something silly. Meet Me I will be at the event for three days straight. I will be around the SQL tracks. Please stop by and introduce yourself. I would like to meet you and talk to you. Meeting folks from the Community is very important as we all speak the same language at the end of the day – SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, SQLServer, T SQL, Technology

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  • SQL SERVER – Validating Unique Columnname Across Whole Database

    - by pinaldave
    I sometimes come across very strange requirements and often I do not receive a proper explanation of the same. Here is the one of those examples. Asker: “Our business requirement is when we add new column we want it unique across current database.” Pinal: “Why do you have such requirement?” Asker: “Do you know the solution?” Pinal: “Sure I can come up with the answer but it will help me to come up with an optimal answer if I know the business need.” Asker: “Thanks – what will be the answer in that case.” Pinal: “Honestly I am just curious about the reason why you need your column name to be unique across database.” (Silence) Pinal: “Alright – here is the answer – I guess you do not want to tell me reason.” Option 1: Check if Column Exists in Current Database IF EXISTS (  SELECT * FROM sys.columns WHERE Name = N'NameofColumn') BEGIN SELECT 'Column Exists' -- add other logic END ELSE BEGIN SELECT 'Column Does NOT Exists' -- add other logic END Option 2: Check if Column Exists in Current Database in Specific Table IF EXISTS (  SELECT * FROM sys.columns WHERE Name = N'NameofColumn' AND OBJECT_ID = OBJECT_ID(N'tableName')) BEGIN SELECT 'Column Exists' -- add other logic END ELSE BEGIN SELECT 'Column Does NOT Exists' -- add other logic END I guess user did not want to share the reason why he had a unique requirement of having column name unique across databases. Here is my question back to you – have you faced a similar situation ever where you needed unique column name across a database. If not, can you guess what could be the reason for this kind of requirement?  Additional Reference: SQL SERVER – Query to Find Column From All Tables of Database Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL System Table, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Excel Losing Decimal Values When Value Pasted from SSMS ResultSet

    - by pinaldave
    No! It is not a SQL Server Issue or SSMS issue. It is how things work. There is a simple trick to resolve this issue. It is very common when users are coping the resultset to Excel, the floating point or decimals are missed. The solution is very much simple and it requires a small adjustment in the Excel. By default Excel is very smart and when it detects the value which is getting pasted is numeric it changes the column format to accommodate that. Now as Zero which are training any digit after decimal points have no value, Excel automatically hides it. To prevent this to happen user has to convert columns to text format so it can preserve the formatting. Here is how you can do it. Select the corner between A and 1 and Right Click on it. It will select complete spreadsheet. If you want to change the format of any column you can select an individual column the same way. In the menu Click on Format Cells… It will bring up the following menu. Here by default the selected column will be General, change that to Text. It will change the format of all the cells to Text. Now once again paste the values from SSMS to the Excel. This time it will preserve the decimal values from SSMS. Solved! Any other trick you do you know to preserve the decimal values? Leave a comment please. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology Tagged: Excel

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  • SQL SERVER – Discard Results After Query Execution – SSMS

    - by pinaldave
    The first thing I do any day is to turn on the computer. Today I woke up and as soon as I turned on the computer I saw a chat message from a friend. He was a bit confused and wanted me to help him. Just as usual I am keeping the relevant conversation in focus and documenting our conversation as chat. Let us call him Ajit. Ajit: Pinal, every time I run a query there is no result displayed in the SSMS but when I run the query in my application it works and returns an appropriate result. Pinal:  Have you tried with different parameters? Ajit: Same thing. However, it works from another computer when I connect to the same server with the same query parameters? Pinal: What? That is new and I believe it is something to do with SSMS and not with the server. Send me screenshot please. Ajit: I believe so, let me send you a screenshot, Pinal: (looking at the screenshot) Oh man, there is no result-tab at all. Ajit: That is what the problem is. It does not have the tab which displays the result. This works just fine from another computer. Pinal: Have you referred Nakul’s blog post – SSMS – Query result options – Discard result after query executes, that talks about setting which can discard the query results after execution. (After a while) Ajit: I think it seems like on the computer where I am running the query my SSMS seems to have the option enabled related to discarding results. I fixed it by following Nakul’s blog post. Pinal: Great! Quite often I get the question what is the importance of the feature. Let us first see how to turn on or turn off this feature in SQL Server Management Studio 2012. In SSMS 2012 go to Tools >> Options >> Query Results > SQL Server >> Results to Grid >> Discard Results After Query Execution. When enabled this option will discard results after the execution. The advantage of disabling the option is that it will improve the performance by using less memory. However the real question is why would someone enable or disable the option. What are the cases when someone wants to run the query but do not care about the result? Matter of the fact, it does not make sense at all to run query and not care about the result. The matter of the fact, I can see quite a few reasons for using this option. I often enable this option when I am doing performance tuning exercise. During performance tuning exercise when I am working with execution plans and do not need results to verify every time or when I am tuning Indexes and its effect on execution plan I do not need the results. In this kind of situations I do keep this option on and discard the results. It always helps me big time as in most of the performance tuning exercise I am dealing with huge amount of the data and dealing with this data can be expensive. Nakul’s has done the experiment here already but I am going to repeat the same again using AdventureWorks Database. Run following T-SQL Script with and without enabling the option to discard the results. USE AdventureWorks2012 GO SELECT * FROM Sales.SalesOrderDetail GO 10 After enabling Discard Results After Query Execution After disabling Discard Results After Query Execution Well, this is indeed a good option when someone is debugging the execution plan or does not want the result to be displayed. Please note that this option does not reduce IO or CPU usage for SQL Server. It just discards the results after execution and a good help for debugging on the development server. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – A Puzzle Part 4 – Fun with SEQUENCE in SQL Server 2012 – Guess the Next Value

    - by pinaldave
    It seems like every weekend I get a new puzzle in my mind. Before continuing I suggest you read my previous posts here where I have shared earlier puzzles. A Puzzle – Fun with SEQUENCE in SQL Server 2012 – Guess the Next Value  A Puzzle Part 2 – Fun with SEQUENCE in SQL Server 2012 – Guess the Next Value A Puzzle Part 3 – Fun with SEQUENCE in SQL Server 2012 – Guess the Next Value After reading above three posts, I am very confident that you all will be ready for the next set of puzzles now. First execute the script which I have written here. Now guess what will be the next value as requested in the query. USE TempDB GO -- Create sequence CREATE SEQUENCE dbo.SequenceID AS DECIMAL(3,0) START WITH 1 INCREMENT BY -1 MINVALUE 1 MAXVALUE 3 CYCLE NO CACHE; GO SELECT next value FOR dbo.SequenceID; -- Guess the number SELECT next value FOR dbo.SequenceID; -- Clean up DROP SEQUENCE dbo.SequenceID; GO Please note that Starting value is 1, Increment value is the negative value of -1 and Minimum value is 3. Now let us first assume how this will work out. In our example of the sequence starting value is equal to 1 and decrement value is -1, this means the value should decrement from 1 to 0. However, the minimum value is 1. This means the value cannot further decrement at all. What will happen here? The natural assumption is that it should throw an error. How many of you are assuming about query will throw an ERROR? Well, you are WRONG! Do not blame yourself, it is my fault as I have told you only half of the story. Now if you have voted for error, let us continue running above code in SQL Server Management Studio. The above script will give the following output: Isn’t it interesting that instead of error out it is giving us result value 3. To understand the answer about the same, carefully observe the original syntax of creating SEQUENCE – there is a keyword CYCLE. This keyword cycles the values between the minimum and maximum value and when one of the range is exhausted it cycles the values from the other end of the cycle. As we have negative incremental value when query reaches to the minimum value or lower end it will cycle it from the maximum value. Here the maximum value is 3 so the next logical value is 3. If your business requirement is such that if sequence reaches the maximum or minimum value, it should throw an error, you should not use the keyword cycle, and it will behave as discussed. I hope, you are enjoying the puzzles as much as I am enjoying it. If you have any interesting puzzle to share, please do share with me and I will share this on blog with due credit to you. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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  • SQL SERVER – #TechEdIn – Presenting Tomorrow on Speed Up! – Parallel Processes and Unparalleled Performance at TechEd India 2012

    - by pinaldave
    Performance tuning is always a very hot topic when it is about SQL Server. SQL Server Performance Tuning is a very challenging subject that requires expertise in Database Administration and Database Development. I always have enjoyed talking about SQL Server Performance tuning subject. However, in India, it’s actually the very first time someone is presenting on this interesting subject, so this time I had the biggest challenge to present this session. Frequently enough, we get these two kind of questions: How to turn off parallelism as it is reducing performance? How to turn on parallelism as I want more performance? The reality is that not everyone knows what exactly is needed by their system. In this session, I have attempted to answer this very question. I’ve decided to provide a balanced view but stay away from theory, which leads us to say “It depends”. The session will have a clear message about this towards its end. Deck Details Slides: 45+ Demos: 7+ Bonus Quiz: 5 Images: 10+ Session delivery time: 52 Mins + 8 Mins of Q & A I have presented this session a couple of times to my friends and so far have received good feedback. Oftentimes, when people hear that I am going to present 45 slides, they all say it is too much to cover. However, when I am done with the session the usual reaction is that I truly gave justice to those slides. Action Item Here are a few of the action items for all of those who are going to attend this session: If you want to attend the session, just come early. There’s a good chance that you may not get a seat because right before me, there is a session from SQL Guru Vinod Kumar. He performs a powerful delivery of million concepts in just a little time. Quiz. I will be asking few questions during the session as well as before the session starts. If you get the correct answer, I will give unique learning material for you. You may not want to miss this learning opportunity at any cosst. Session Details Title: Speed Up! – Parallel Processes and Unparalleled Performance (Add to Calendar) Abstract: “More CPU, More Performance” – A  very common understanding is that usage of multiple CPUs can improve the performance of the query. To get a maximum performance out of any query, one has to master various aspects of the parallel processes. In this deep-dive session, we will explore this complex subject with a very simple interactive demo. Attendees will walk away with proper understanding of CX_PACKET wait types, MAXDOP, parallelism threshold and various other concepts. Date and Time: March 23, 2012, 12:15 to 13:15 Location: Hotel Lalit Ashok - Kumara Krupa High Grounds, Bengaluru – 560001, Karnataka, India. Add to Calendar Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Interview Questions and Answers, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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  • SQL SERVER – Importance of User Without Login

    - by pinaldave
    Some questions are very open ended and it is very hard to come up with exact requirements. Here is one question I was asked in recent User Group Meeting. Question: “In recent version of SQL Server we can create user without login. What is the use of it?” Great question indeed. Let me first attempt to answer this question but after reading my answer I need your help. I want you to help him as well with adding more value to it. Answer: Let us visualize a scenario. An application has lots of different operations and many of them are very sensitive operations. The common practice was to do give application specific role which has more permissions and access level. When a regular user login (not system admin), he/she might have very restrictive permissions. The application itself had a user name and password which means applications can directly login into the database and perform the operation. Developers were well aware of the username and password as it was embedded in the application. When developer leaves the organization or when the password was changed, the part of the application had to be changed where the same username and passwords were used. Additionally, developers were able to use the same username and password and login directly to the same application. In earlier version of SQL Server there were application roles. The same is later on replaced by “User without Login”. Now let us recreate the above scenario using this new “User without Login”. In this case, User will have to login using their own credentials into SQL Server. This means that the user who is logged in will have his/her own username and password. Once the login is done in SQL Server, the user will be able to use the application. Now the database should have another User without Login which has all the necessary permissions and rights to execute various operations. Now, Application will be able to execute the script by impersonating “user without login – with more permissions”. Here there is assumed that user login does not have enough permissions and another user (without login) there are more rights. If a user knows how the application is using the database and their various operations, he can switch the context to user without login making him enable for doing further modification. Make sure to explicitly DENY view definition permission on the database. This will make things further difficult for user as he will have to know exact details to get additional permissions. If a user is System Admin all the details which I just mentioned in above three paragraphs does not apply as admin always have access to everything. Additionally, the method describes above is just one of the architecture and if someone is attempting to damage the system, they will still be able to figure out a workaround. You will have to put further auditing and policy based management to prevent such incidents and accidents. I guess this is my answer. I read it multiple times but I still feel that I am missing something. There should be more to this concept than what I have just described. I have merely described one scenario but there will be many more scenarios where this situation will be useful. Now is your turn to help – please leave a comment with the additional suggestion where exactly “User without Login” will be useful as well did I miss anything when I described above scenario. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Fix : Error 3623 – An invalid floating point operation occurred

    - by pinaldave
    Going back in time, I always had a problem with mathematics. It was a great subject and I loved it a lot but I only mastered it after practices a lot. I learned that mathematics problems should be addressed systematically and being verbose is not a trick, I learned to solve any problem. Recently one of reader sent me an email with the title “Mathematics problem – please help!” and I was a bit scared. I was good at mathematics but not the best. When I opened the email I was relieved as it was Mathematics problem with SQL Server. My friend received following error while working with SQL Server. Msg 3623, Level 16, State 1, Line 1 An invalid floating point operation occurred. The reasons for the error is simply that invalid usage of the mathematical function is attempted. Let me give you a few examples of the same. SELECT SQRT(-5); SELECT ACOS(-3); SELECT LOG(-9); If you run any of the above functions they will give you an error related to invalid floating point. Honestly there is no workaround except passing the function appropriate values. SQRT of a negative number will give you result in real numbers which is not supported at this point of time as well LOG of a negative number is not possible (because logarithm is the inverse function of an exponential function and the exponential function is NEVER negative). When I send above reply to my friend he did understand that he was passing incorrect value to the function. As mentioned earlier the only way to fix this issue is finding incorrect value and avoid passing it to the function. Every mathematics function is different and there is not a single solution to identify erroneous value passed. If you are facing this error and not able to figure out the solution. Post a comment and I will do my best to figure out the solution. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Error Messages, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Challenge – Puzzle – Usage of FAST Hint

    - by pinaldave
    I was recently working with various SQL Server Hints. After working for a day on various hints, I realize that for one hint, I am not able to come up with good example. The hint is FAST. Let us look at the definition of the FAST hint from the Book On-Line. FAST number_rows Specifies that the query is optimized for fast retrieval of the first number_rows. This is a nonnegative integer. After the first number_rows are returned, the query continues execution and produces its full result set. Now the question is in what condition this hint can be useful. I have tried so many different combination, I have found this hint does not make much performance difference, infect I did not notice any change in time taken to load the resultset. I noticed that this hint does not change number of the page read to return result. Now when there is difference in performance is expected because if you read the what FAST hint does is that it only returns first few results FAST – which does not mean there will be difference in performance. I also understand that this hint gives the guidance/suggestions/hint to query optimizer that there are only 100 rows are in expected resultset. This tricking the optimizer to think there are only 100 rows and which (may) lead to render different execution plan than the one which it would have taken in normal case (without hint). Again, not necessarily, this will happen always. Now if you read above discussion, you will find that basic understanding of the hint is very clear to me but I still feel that I am missing something. Here are my questions: 1) In what condition this hint can be useful? What is the case, when someone want to see first few rows early because my experience suggests that when first few rows are rendered remaining rows are rendered as well. 2) Is there any way application can retrieve the fast fetched rows from SQL Server? 3) Do you use this hint in your application? Why? When? and How? Here are few examples I have attempted during the my experiment and found there is no difference in execution plan except its estimated number of rows are different leading optimizer think that the cost is less but in reality that is not the case. USE AdventureWorks GO SET STATISTICS IO ON SET STATISTICS TIME ON GO --------------------------------------------- -- Table Scan with Fast Hint SELECT * FROM Sales.SalesOrderDetail GO SELECT * FROM Sales.SalesOrderDetail OPTION (FAST 100) GO --------------------------------------------- -- Table Scan with Where on Index Key SELECT * FROM Sales.SalesOrderDetail WHERE OrderQty = 14 GO SELECT * FROM Sales.SalesOrderDetail WHERE OrderQty = 14 OPTION (FAST 100) GO --------------------------------------------- -- Table Scan with Where on Index Key SELECT * FROM Sales.SalesOrderDetail WHERE SalesOrderDetailID < 1000 GO SELECT * FROM Sales.SalesOrderDetail WHERE SalesOrderDetailID < 1000 OPTION (FAST 100) GO Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – 2011 – Introduction to SEQUENCE – Simple Example of SEQUENCE

    - by pinaldave
    SQL Server 2011 will contain one of the very interesting feature called SEQUENCE. I have waited for this feature for really long time. I am glad it is here finally. SEQUENCE allows you to define a single point of repository where SQL Server will maintain in memory counter. USE AdventureWorks2008R2 GO CREATE SEQUENCE [Seq] AS [int] START WITH 1 INCREMENT BY 1 MAXVALUE 20000 GO SEQUENCE is very interesting concept and I will write few blog post on this subject in future. Today we will see only working example of the same. Let us create a sequence. We can specify various values like start value, increment value as well maxvalue. -- First Run SELECT NEXT VALUE FOR Seq, c.CustomerID FROM Sales.Customer c GO -- Second Run SELECT NEXT VALUE FOR Seq, c.AccountNumber FROM Sales.Customer c GO Once the sequence is defined, it can be fetched using following method. Every single time new incremental value is provided, irrespective of sessions. Sequence will generate values till the max value specified. Once the max value is reached, query will stop and will return error message. Msg 11728, Level 16, State 1, Line 2 The sequence object ‘Seq’ has reached its minimum or maximum value. Restart the sequence object to allow new values to be generated. We can restart the sequence from any particular value and it will work fine. -- Restart the Sequence ALTER SEQUENCE [Seq] RESTART WITH 1 GO -- Sequence Restarted SELECT NEXT VALUE FOR Seq, c.CustomerID FROM Sales.Customer c GO Let us do final clean up. -- Clean Up DROP SEQUENCE [Seq] GO There are lots of things one can find useful about this feature. We will see that in future posts. Here is the complete code for easy reference. USE AdventureWorks2008R2 GO CREATE SEQUENCE [Seq] AS [int] START WITH 1 INCREMENT BY 1 MAXVALUE 20000 GO -- First Run SELECT NEXT VALUE FOR Seq, c.CustomerID FROM Sales.Customer c GO -- Second Run SELECT NEXT VALUE FOR Seq, c.AccountNumber FROM Sales.Customer c GO -- Restart the Sequence ALTER SEQUENCE [Seq] RESTART WITH 1 GO -- Sequence Restarted SELECT NEXT VALUE FOR Seq, c.CustomerID FROM Sales.Customer c GO -- Clean Up DROP SEQUENCE [Seq] GO Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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  • SQL SERVER – CSVExpress and Quick Data Load

    - by pinaldave
    One of the newest ETL tools is CSVexpress.com.  This is a program that can quickly load any CSV file into ODBC compliant databases uses data integration.  For those of you familiar with databases and how they operate, the question that comes to mind might be what use this program will have in your life. I have written earlier article on this subject over here SQL SERVER – Import CSV into Database – Transferring File Content into a Database Table using CSVexpress. You might know that RDBMS have automatic support for loading CSV files into tables – but it is not quite as easy as one click of a button.  First of all, most databases have a command line interface and you need the file and configuration script in order to load up.  You also need to know enough to write the script – which for novices can be extremely daunting.  On top of all this, if you work with more than one type of RDBMS, you need to know the ins and outs of uploading and writing script for more than one program. So you might begin to see how useful CSVexpress.com might be!  There are many other tools that enable uploading files to a database.  They can be very fancy – some can generate configuration files automatically, others load the data directly.  Again, novices will be able to tell you why these aren’t the most useful programs in the world.  You see, these programs were created with SQL in mind, not for uploading data.  If you don’t have large amounts of data to upload, getting the configurations right can be a long process and you will have to check the code that is generated yourself.  Not exactly “easy to use” for novices. That makes CSVexpress.com one of the best new tools available for everyone – but especially people who don’t want to learn a lot of new material all at once.  CSVexpress has an easy to navigate graphical user interface and no scripting or coding is required.  There are built-in constraints and data validations, and you can configure transforms and reject records right there on the screen.  But the best thing of all – it’s free! That’s right, you can download CSVexpress for free from www.csvexpress.com and start easily uploading and configuring riles almost immediately.  If you’re currently happy with your method of data configuration, keep up with the good work.  For the rest of us, there’s CSVexpress.com. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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  • SQL SERVER – Validating Spatial Object with IsValidDetailed Function

    - by pinaldave
    What do you prefer – error or warning indicating error may happen with the reason for the error. While writing the previous statement I remember the movie “Minory Report”. This blog post is not about minority report but I will still cover the concept in a single statement “Let us predict the future and prevent the crime which is about to happen in future”. (Please feel free to correct me if I am wrong about the movie concept, I really do not want to hurt your sentiment if you are dedicated fan). Let us switch to the SQL Server world. Spatial data types are interesting concepts. I love writing about spatial data types because it allows me to be creative with shapes (just like toddlers). When working with Spatial Datatypes it is all good when the spatial object works fine. However, when the spatial object has issue or it is created with invalid coordinates it used to give a simple error that there is an issue with the object but did not provide much information. This made it very difficult to debug. If this spatial object was used in the big procedure and while this big procedural error out because of the invalid spatial object, it is indeed very difficult to debug it. I always wished that the more information provided regarding what is the problem with spatial datatype. SQL Server 2012 has introduced the new function IsValidDetailed(). This function has made my life very easy. In simple words this function will check if the spatial object passed is valid or not. If it is valid it will give information that it is valid. If the spatial object is not valid it will return the answer that it is not valid and the reason for the same. This makes it very easy to debug the issue and make the necessary correction. DECLARE @p GEOMETRY = 'Polygon((2 2, 6 6, 4 2, 2 2))' SELECT @p.IsValidDetailed() GO DECLARE @p GEOMETRY = 'Polygon((2 2, 3 3, 4 4, 5 5, 6 6, 2 2))' SELECT @p.IsValidDetailed() GO DECLARE @p GEOMETRY = 'Polygon((2 2, 4 4, 4 2, 2 3, 2 2))' SELECT @p.IsValidDetailed() GO DECLARE @p GEOMETRY = 'CIRCULARSTRING(2 2, 4 4, 0 0)' SELECT @p.IsValidDetailed() GO DECLARE @p GEOMETRY = 'CIRCULARSTRING(2 2, 4 4, 0 0)' SELECT @p.IsValidDetailed() GO DECLARE @p GEOMETRY = 'LINESTRING(2 2, 4 4, 0 0)' SELECT @p.IsValidDetailed() GO Here is the resultset of the above query. You can see any valid query and some invalid query. If the query is invalid it also demonstrates the reason along with the error message. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Spatial Database, SQL Spatial

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  • SQL SERVER – How to easily work with Database Diagrams

    - by Pinal Dave
    Databases are very widely used in the modern world. Regardless of the complexity of a database, each one requires in depth designing. To practice along please Download dbForge Studio now.  The right methodology of designing a database is based on the foundations of data normalization, according to which we should first define database’s key elements – entities. Afterwards the attributes of entities and relations between them are determined. There is a strong opinion that the process of database designing should start with a pencil and a blank sheet of paper. This might look old-fashioned nowadays, because SQL Server provides a much wider functionality for designing databases – Database Diagrams. When using SSMS for working with Database Diagrams I realized two things – on the one hand, visualization of a scheme allows designing a database more efficiently; on the other – when it came to creating a big scheme, some difficulties occurred when designing with SSMS. The alternatives haven’t taken long to wait and dbForge Studio for SQL Server is one of them. Its functions offer more advantages for working with Database Diagrams. For example, unlike SSMS, dbForge Studio supports an opportunity to drag-and-drop several tables at once from the Database Explorer. This is my opinion but personally I find this option very useful. Another great thing is that a diagram can be saved as both a graphic file and a special XML file, which in case of identical environment can be easily opened on the other server for continuing the work. During working with dbForge Studio it turned out that it offers a wide set of elements to operate with on the diagram. Noteworthy among such elements are containers which allow aggregating diagram objects into thematic groups. Moreover, you can even place an image directly on the diagram if the scheme design is based on a standard template. Each of the development environments has a different approach to storing a diagram (for example, SSMS stores them on a server-side, whereas dbForge Studio – in a local file). I haven’t found yet an ability to convert existing diagrams from SSMS to dbForge Studio. However I hope Devart developers will implement this feature in one of the following releases. All in all, editing Database Diagrams through dbForge Studio was a nice experience and allowed speeding-up the common database designing tasks. Download dbForge Studio now. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL

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  • SQL SERVER – Weekly Series – Memory Lane – #007

    - by pinaldave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2006 Find Stored Procedure Related to Table in Database – Search in All Stored Procedure In 2006 I wrote a small script which will help user  find all the Stored Procedures (SP) which are related to one or more specific tables. This was quite a popular script however, in SQL Server 2012 the same can be achieved using new DMV sys.sql-expression_dependencies. I recently blogged about it over Find Referenced or Referencing Object in SQL Server using sys.sql_expression_dependencies. 2007 SQL SERVER – Versions, CodeNames, Year of Release 1993 – SQL Server 4.21 for Windows NT 1995 – SQL Server 6.0, codenamed SQL95 1996 – SQL Server 6.5, codenamed Hydra 1999 – SQL Server 7.0, codenamed Sphinx 1999 – SQL Server 7.0 OLAP, codenamed Plato 2000 – SQL Server 2000 32-bit, codenamed Shiloh (version 8.0) 2003 – SQL Server 2000 64-bit, codenamed Liberty 2005 – SQL Server 2005, codenamed Yukon (version 9.0) 2008 – SQL Server 2008, codenamed Katmai (version 10.0) 2011 – SQL Server 2008, codenamed Denali (version 11.0) Search String in Stored Procedure Searching sting in the stored procedure is one of the most frequent task developer do. They might be searching for a table, view or any other details. I have written a script to do the same in SQL Server 2000 and SQL Server 2005. This is worth bookmarking blog post. There is an alternative way to do the same as well here is the example. 2008 SQL SERVER – Refresh Database Using T-SQL NO! Some of the questions have a single answer NO! You may want to read the question in the original blog post. I had a great time saying No! SQL SERVER – Delete Backup History – Cleanup Backup History SQL Server stores history of all the taken backup forever. History of all the backup is stored in the msdb database. Many times older history is no more required. Following Stored Procedure can be executed with a parameter which takes days of history to keep. In the following example 30 is passed to keep a history of month. 2009 Stored Procedure are Compiled on First Run – SP taking Longer to Run First Time Is stored procedure pre-compiled? Why the Stored Procedure takes a long time to run for the first time?  This is a very common questions often discussed by developers and DBAs. There is an absolutely definite answer but the question has been discussed forever. There is a misconception that stored procedures are pre-compiled. They are not pre-compiled, but compiled only during the first run. For every subsequent runs, it is for sure pre-compiled. Read the entire article for example and demonstration. Removing Key Lookup – Seek Predicate – Predicate – An Interesting Observation Related to Datatypes This is one of the most important performance tuning lesson on my blog. I suggest this weekend you spend time reading them and let me know what you think about the concepts which I have demonstrated in the four part series. Part 1 | Part 2 | Part 3 | Part 4 Seek Predicate is the operation that describes the b-tree portion of the Seek. Predicate is the operation that describes the additional filter using non-key columns. Based on the description, it is very clear that Seek Predicate is better than Predicate as it searches indexes whereas in Predicate, the search is on non-key columns – which implies that the search is on the data in page files itself. Policy Based Management – Create, Evaluate and Fix Policies This article will cover the most spectacular feature of SQL Server – Policy-based management and how the configuration of SQL Server with policy-based management architecture can make a powerful difference. Policy based management is loaded with several advantages. It can help you implement various policies for reliable configuration of the system. It also provides additional administration assistance to DBAs and helps them effortlessly manage various tasks of SQL Server across the enterprise. 2010 Recycle Error Log – Create New Log file without Server Restart Once I observed a DBA to restaring the SQL Server when he needed new error log file. This was funny and sad both at the same time. There is no need to restart the server to create a new log file or recycle the log file. You can run sp_cycle_errorlog and achieve the same result. Get Database Backup History for a Single Database Simple but effective script! Reducing CXPACKET Wait Stats for High Transactional Database The subject is very complex and I have done my best to simplify the concept. In simpler words, when a parallel operation is created for SQL Query, there are multiple threads for a single query. Each query deals with a different set of the data (or rows). Due to some reasons, one or more of the threads lag behind, creating the CXPACKET Wait Stat. Threads which came first have to wait for the slower thread to finish. The Wait by a specific completed thread is called CXPACKET Wait Stat. Information Related to DATETIME and DATETIME2 There are quite a lot of confusion with DATETIME and DATETIME2. DATETIME2 is also one of the underutilized datatype of SQL Server.  In this blog post I have written a follow up of the my earlier datetime series where I clarify a few of the concepts related to datetime. Difference Between GETDATE and SYSDATETIME Difference Between DATETIME and DATETIME2 – WITH GETDATE Difference Between DATETIME and DATETIME2 2011 Introduction to CUME_DIST – Analytic Functions Introduced in SQL Server 2012 SQL Server 2012 introduces new analytical function CUME_DIST(). This function provides cumulative distribution value. It will be very difficult to explain this in words so I will attempt small example to explain you this function. Instead of creating new table, I will be using AdventureWorks sample database as most of the developer uses that for experiment. Introduction to FIRST _VALUE and LAST_VALUE – Analytic Functions Introduced in SQL Server 2012 SQL Server 2012 introduces new analytical functions FIRST_VALUE() and LAST_VALUE(). This function returns first and last value from the list. It will be very difficult to explain this in words so I’d like to attempt to explain its function through a brief example. Instead of creating a new table, I will be using the AdventureWorks sample database as most developers use that for experiment purposes. OVER clause with FIRST _VALUE and LAST_VALUE – Analytic Functions Introduced in SQL Server 2012 – ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING “Don’t you think there is bug in your first example where FIRST_VALUE is remain same but the LAST_VALUE is changing every line. I think the LAST_VALUE should be the highest value in the windows or set of result.” Puzzle – Functions FIRST_VALUE and LAST_VALUE with OVER clause and ORDER BY You can see that row number 2, 3, 4, and 5 has same SalesOrderID = 43667. The FIRST_VALUE is 78 and LAST_VALUE is 77. Now if these function was working on maximum and minimum value they should have given answer as 77 and 80 respectively instead of 78 and 77. Also the value of FIRST_VALUE is greater than LAST_VALUE 77. Why? Explain in detail. Introduction to LEAD and LAG – Analytic Functions Introduced in SQL Server 2012 SQL Server 2012 introduces new analytical function LEAD() and LAG(). This functions accesses data from a subsequent row (for lead) and previous row (for lag) in the same result set without the use of a self-join . It will be very difficult to explain this in words so I will attempt small example to explain you this function. Instead of creating new table, I will be using AdventureWorks sample database as most of the developer uses that for experiment. A Real Story of Book Getting ‘Out of Stock’ to A 25% Discount Story Available Our book was out of stock in 48 hours of it was arrived in stock! We got call from the online store with a request for more copies within 12 hours. But we had printed only as many as we had sent them. There were no extra copies. We finally talked to the printer to get more copies. However, due to festivals and holidays the copies could not be shipped to the online retailer for two days. We knew for sure that they were going to be out of the book for 48 hours. This is the story of how we overcame that situation! Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Free Print Book on SQL Server Joes 2 Pros Kit

    - by pinaldave
    Rick Morelan and I were discussing earlier this month that what we can give back to the community. We believe our books are very much successful and very well received by the community. The five books are a journey from novice to expert. The books have changed many lives and helped many get jobs as well pass the SQL Certifications. Rick is from Seattle, USA and I am from Bangalore, India. There are 12 hours difference between us. We try to do weekly meeting to catch up on various personal and SQL related topics. Here is one of our recent conversations. Rick and Pinal Pinal: Good Morning Rick! Rick: Good Morning…err… Good Evening to you – Pinal! Pinal: Hey Rick, did you read the recent email which I sent you – one of our reader is thanking us for writing Joes 2 Pros series. He wants to dedicate his success to us. Can you believe it? Rick: Yeah, he is very kind but did you tell him that it is all because of his hard work on learning subject and we have very little contribution in his success. Pinal: Absolutely, I told him the same – I said we just wrote the book but it is he who learned from it and proved himself in his job. It is all him! We were just igniters. Rick: Good response. Pinal: Hey Rick! Are we doing enough for the community? What can we do more? Rick: Hmmm… Let us do something more. Pinal: Remember once we discussed the idea of if anyone who buys our Joes 2 Pros Combo Kit in the next 2 weeks – we will send them SQL Wait Stats for free. What do you say? Rick: I agree! Great Idea! Let us do it. Free Giveaway Well Rick and I liked the idea of doing more. We have decided to give away free SQL Server Wait Stats books to everybody who will purchase Joes 2 Pros Combo Kit between today (Oct 15, 2012) and Oct 26, 2012. This is not a contest or a lucky winner opportunity. Everybody who participates will qualify for it. Combo Availability USA – Amazon India - Flipkart | Indiaplaza Note1: USA kit contains FREE 5 DVDs. India Kit does not contain 5 DVDs due to legal issues. Note2: Indian Kit is priced at special Indian Economic Price. Qualify for Free Giveaway You must have purchased our Joes 2 Pros Combo Kit of 5 books between Oct 15, 2012 and Oct 26, 2012. Purchase before Oct 15, 2012 and after Oct 26, 2012 will not qualify for this giveaway. Send your original receipt (email, order details) to following addresses: “[email protected];[email protected]” with the subject line “Joes 2 Pros Kit Promotion Free Offer”. Do not change the subject line or your email may be missed.  Clearly mention your shipping address with phone number and pin/zip code. Send your receipt before Oct 30, 2012. We will not entertain any conversation after Oct 30, 2012 cut off date. The Free books will be sent to USA and India address only. Availability USA - Amazon | India - Flipkart | Indiaplaza Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Book Review, SQLServer, T SQL, Technology

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  • SQL SERVER – Enable Identity Insert – Import Expert Wizard

    - by pinaldave
    I recently got email from old friend who told me that when he tries to execute SSIS package it fails with some identity error. After some debugging and opening his package we figure out that he has following issue. Let us see what kind of set up he had on his package. Source Table with Identity column Destination Table with Identity column Following checkbox was disabled in Import Expert Wizard (as per the image below) What did we do is we enabled the checkbox described as above and we fixed the problem he was having due to insertion in identity column. The reason he was facing this error because his destination table had IDENTITY property which will not allow any  insert from user. This value is automatically generated by system when new values are inserted in the table. However, when user manually tries to insert value in the table, it stops them and throws an error. As we enabled the checkbox “Enable Identity Insert”, this feature allowed the values to be insert in the identity field and this way from source database exact identity values were moved to destination table. Let me know if this blog post was easy to understand. Reference: Pinal Dave (http://blog.SQLAuthority.com), Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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  • SQL SERVER – 2 T-SQL Puzzles and Win USD 50 worth Amazon Gift Card and 25 Other Prizes

    - by pinaldave
    We all love brain teasers and interesting puzzles. Today I decided to come up with 2 interesting puzzles and winner of the contest will get USD 50 worth Amazon Gift Card. The puzzles are sponsored by NuoDB. Additionally, The first 25 individuals who download NuoDB Beta 8 by midnight Friday, Sept. 21 (EST) will automatically receive a $10 Amazon gift card. Puzzle 1: Why following code when executed in SSMS displays result as a * (Star)? SELECT CAST(634 AS VARCHAR(2)) Puzzle 2: Write the shortest code that produces results as 1 without using any numbers in the select statement. Bonus Q: How many different Operating System (OS) NuoDB support? Click here HINT If you can solve above puzzles you will be eligible for winning USD 50 Amazon Gift Card. However, you can always enroll yourself for following Bonus Prizes where if you have good chance of winning USD 10 Amazon Gift Card (if you are first 25 individual in specific time). Bonus Prizes: The first 25 individuals who download NuoDB Beta 8 by midnight Friday, Sept. 21 (EST) will automatically receive a $10 Amazon gift card. Rules: Please leave an answer in the comments section below. You can resubmit your answer multiple times, the latest entry will be considered valid. The winner will be announced on 1st October. Last day to participate in the puzzle is September 28th, 2012. All valid answer will be kept hidden till September 28th, 2012. Only One Winner will get USD 50 worth Amazon Gift Card. The first 25 individuals who download NuoDB Beta 8 by midnight Friday, Sept. 21 (EST) will automatically receive a $10 Amazon gift card. The winner will be selected using random algorithm. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology Tagged: NuoDB

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