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• SQL SERVER – 3 Challenges for DBA and Smart Solutions

  - by Pinal Dave

  Developer’s life is never easy. DBA’s life is even crazier. DBA’s Life When a developer wakes up in the morning, most of the time have no idea what different challenges they are going to face that day. Of course, most of the developers know the project and roadmap, which they are working on. However, developers have no clue what coding challenges which they are going face for that day. DBA’s life is even crazier. When DBA wakes up in the morning – they often thank that they were not disturbed during the night due to server issues. The very next thing they wish is that they do not want to challenge which they can’t solve for that day. The problems DBA face every single day are mostly unpredictable and they just have to solve them as they come during the day. Though the life of DBA is not always bad. There are always ways and methods how one can overcome various challenges. Let us see three of the challenges and how a DBA can use various tools to overcome them. Challenge #1 Synchronize Data Across Server A Very common challenge DBA receive is that they have to synchronize the data across the servers. If you try to manually write that up, it may take forever to accomplish the task. It is nearly impossible to do the same with the help of the T-SQL. However, thankfully there are tools like dbForge Studio which can save a day and synchronize data across servers. Read my detailed blog post about the same over here: SQL SERVER – Synchronize Data Exclusively with T-SQL. Challenge #2 SQL Report Builder DBA’s are often asked to build reports on the go. It really annoys DBA’s, but hardly people care about it. No matter how busy a DBA is, they are just called upon to build reports on things on very short notice. I personally like to avoid any task which is given to me accidently and personally building report can be boring. I rather spend time with High Availability, disaster recovery, performance tuning rather than building report. I use SQL third party tool when I have to work with SQL Report. Others have extended reporting capabilities. The latter group of products includes the SQL report builder built-in todbForge Studio for SQL Server. I have blogged about this earlier over here: SQL SERVER – SQL Report Builder in dbForge Studio for SQL Server. Challenge #3 Work with the OTHER Database The manager does not understand that MySQL is different from SQL Server and SQL Server is different from Oracle. For them everything is same. In my career hundreds of times I have faced a situation that I am given a database to manage or do some task when their regular DBA is on vacation or leave. When I try to explain I do not understand the underlying the technology, I have been usually told that my manager has trust on me and I can do anything. Honestly, I can’t but I hardly dare to argue. I fall back on the third party tool to manage database when it is not in my comfort zone. For example, I was once given MySQL performance tuning task (at that time I did not know MySQL so well). To simplify search for a problem query let us use MySQL Profiler in dbForge Studio for MySQL. It provides such commands as a Query Profiling Mode and Generate Execution Plan. Here is the blog post discussing about the same: MySQL – Profiler : A Simple and Convenient Tool for Profiling SQL Queries. Well, that’s it! There were many different such occasions when I have been saved by the tool. May be some other day I will write part 2 of this blog post. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: MySQL, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL Tagged: Devart, SQL Tool

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• SQL SERVER – Puzzle – Statistics are not Updated but are Created Once

  - by pinaldave

  After having excellent response to my quiz – Why SELECT * throws an error but SELECT COUNT(*) does not?I have decided to ask another puzzling question to all of you. I am running this test on SQL Server 2008 R2. Here is the quick scenario about my setup. Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Note: Auto Update Statistics and Auto Create Statistics for database is TRUE Expected Result – Statistics should be updated – SQL SERVER – When are Statistics Updated – What triggers Statistics to Update Now the question is why the statistics are not updated? The common answer is – we can update the statistics ourselves using UPDATE STATISTICS TableName WITH FULLSCAN, ALL However, the solution I am looking is where statistics should be updated automatically based on algorithm mentioned here. Now the solution is to ____________________. Vinod Kumar is not allowed to take participate over here as he is the one who has helped me to build this puzzle. I will publish the solution on next week. Please leave a comment and if your comment consist valid answer, I will publish with due credit. Here is the script to reproduce the scenario which I mentioned. -- Execution Plans Difference -- Create Sample Database CREATE DATABASE SampleDB GO USE SampleDB GO -- Create Table CREATE TABLE ExecTable (ID INT, FirstName VARCHAR(100), LastName VARCHAR(100), City VARCHAR(100)) GO -- Insert One Thousand Records -- INSERT 1 INSERT INTO ExecTable (ID,FirstName,LastName,City) SELECT TOP 1000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%20 = 1 THEN 'New York' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 5 THEN 'San Marino' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 3 THEN 'Los Angeles' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 7 THEN 'La Cinega' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 13 THEN 'San Diego' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 17 THEN 'Las Vegas' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Display statistics of the table - none listed sp_helpstats N'ExecTable', 'ALL' GO -- Select Statement SELECT FirstName, LastName, City FROM ExecTable WHERE City  = 'New York' GO -- Display statistics of the table sp_helpstats N'ExecTable', 'ALL' GO -- Replace your Statistics over here -- NOTE: Replace your _WA_Sys with stats from above query DBCC SHOW_STATISTICS('ExecTable', _WA_Sys_00000004_7D78A4E7); GO -------------------------------------------------------------- -- Round 2 -- Insert Ten Thousand Records -- INSERT 2 INSERT INTO ExecTable (ID,FirstName,LastName,City) SELECT TOP 10000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%20 = 1 THEN 'New York' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 5 THEN 'San Marino' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 3 THEN 'Los Angeles' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 7 THEN 'La Cinega' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 13 THEN 'San Diego' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 17 THEN 'Las Vegas' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Select Statement SELECT FirstName, LastName, City FROM ExecTable WHERE City  = 'New York' GO -- Display statistics of the table sp_helpstats N'ExecTable', 'ALL' GO -- Replace your Statistics over here -- NOTE: Replace your _WA_Sys with stats from above query DBCC SHOW_STATISTICS('ExecTable', _WA_Sys_00000004_7D78A4E7); GO -- You will notice that Statistics are still updated with 1000 rows -- Clean up Database DROP TABLE ExecTable GO USE MASTER GO ALTER DATABASE SampleDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE; GO DROP DATABASE SampleDB GO Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Statistics, Statistics

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• SQL SERVER – Guest Post – Glenn Berry – Wait Type – Day 26 of 28

  - by pinaldave

  Glenn Berry works as a Database Architect at NewsGator Technologies in Denver, CO. He is a SQL Server MVP, and has a whole collection of Microsoft certifications, including MCITP, MCDBA, MCSE, MCSD, MCAD, and MCTS. He is also an Adjunct Faculty member at University College – University of Denver, where he has been teaching since 2000. He is one wonderful blogger and often blogs at here. I am big fan of the Dynamic Management Views (DMV) scripts of Glenn. His script are extremely popular and the reality is that he has inspired me to start this series with his famous DMV which I have mentioned in very first  wait stats blog post (I had forgot to request his permission to re-use the script but when asked later on his whole hearty approved it). Here is is his excellent blog post on this subject of wait stats: Analyzing cumulative wait stats in SQL Server 2005 and above has become a popular and effective technique for diagnosing performance issues and further focusing your troubleshooting and diagnostic  efforts.  Rather than just guessing about what resource(s) that SQL Server is waiting on, you can actually find out by running a relatively simple DMV query. Once you know what resources that SQL Server is spending the most time waiting on, you can run more specific queries that focus on that resource to get a better idea what is causing the problem. I do want to throw out a few caveats about using wait stats as a diagnostic tool. First, they are most useful when your SQL Server instance is experiencing performance problems. If your instance is running well, with no indication of any resource pressure from other sources, then you should not worry that much about what the top wait types are. SQL Server will always be waiting on some resource, but many wait types are quite benign, and can be safely ignored. In spite of this, I quite often see experienced DBAs obsessing over the top wait type, even when their SQL Server instance is running extremely well. Second, I often see DBAs jump to the wrong conclusion based on seeing a particular well-known wait type. A good example is CXPACKET waits. People typically jump to the conclusion that high CXPACKET waits means that they should immediately change their instance-level MADOP setting to 1. This is not always the best solution. You need to consider your workload type, and look carefully for any important “missing” indexes that might be causing the query optimizer to use a parallel plan to compensate for the missing index. In this case, correcting the index problem is usually a better solution than changing MAXDOP, since you are curing the disease rather than just treating the symptom. Finally, you should get in the habit of clearing out your cumulative wait stats with the  DBCC SQLPERF(‘sys.dm_os_wait_stats’, CLEAR); command. This is especially important if you have made an configuration or index changes, or if your workload has changed recently. Otherwise, your cumulative wait stats will be polluted with the old stats from weeks or months ago (since the last time SQL Server was started or the stats were cleared).  If you make a change to your SQL Server instance, or add an index, you should clear out your wait stats, and then wait a while to see what your new top wait stats are. At any rate, enjoy Pinal Dave’s series on Wait Stats. This blog post has been written by Glenn Berry (Twitter | Blog) Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• SQLAuthority News – Follow up on – Replace a Column Name in Multiple Stored Procedure all together

  - by pinaldave

  Last month I had a fantastic time with lots of puzzles and brain teasers, the amount of participation which I have received on the blog is indeed inspiring to write more. One of the blog post was about how to replace a column name in all the stored procedures. The article had very interesting conversation as a follow up. Please read the original article Replace a Column Name in Multiple Stored Procedure all together before reading this blog further as they are connected. Let us start few of the interesting comments. SQL Server Expert Imran Mohammed had a wonderful first and excellent note. I suggest all of you to read it. Imran stresses on the Data Modelling and Logical as well as Physical Design. Developers must create a logical design and get approval on naming convention, data types, references, constraints, indexes etc. He further suggested that one should not cut steps but must follow all the industry standards and guidelines. Here extended my blog post with following note – “Extending Pinal’s answer, what you can do is go to database properties, all tasks, scripts objects, in scripting wizard select all the stored procedure for which you want to change column name, export the query to a new window and then do find and replace, all in once window and execute the script. But make sure you check what you are replacing, sometimes column names are also used in table names, for ex:Table Name: Product and Column Name: ProductId, ProductName”. Thanks Imran Great Points!  Gatej Alexandru suggested that it is not good idea to DROP or CREATE but rather use ALTER as quite possible there may be permissions issue as well. Very good point let me see if I can write blog post over it. Vinay Kumar and SQLStudent144 have proposed another method to achieve the same. I am combining their solution and writing them here. Step 1. Press Ctrl+T or change “Result to Text” mode. Step 2. Execute below commands.SELECT 'EXEC sp_helptext [' + referencing_schema_name + '.' + referencing_entity_name + ']' FROM sys.dm_sql_referencing_entities('schema.objectname','OBJECT') Where schema.objectname is the object or table you are searching for. Step 3. Now copy the result and paste in new window. Again Press Ctrl+T or change “Result to Text” mode. Step 4. Copy the result and paste in new window. Execute the query. Step 5. Copy the result and paste in new window. Step 6. Now find your searching text in the script, make necessary changes and execute this script. Do not forget to remove the code which is generated in resultset which are not relevant to the T-SQL Script. Digitqr suggest we can do this for other objects besides Stored Procedure as well. Iosif suggests to use tool SQL Search from RedGate. I guess this sums it well. We have an alternative perspective to our original issue of replacing the column name in multiple stored procedure. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Speed Up! – Parallel Processes and Unparalleled Performance – TechEd 2012 India

  - by pinaldave

  TechEd India 2012 is just around the corner and I will be presenting there on two different session. 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. Just like doctors I like to call my every attempt to improve the performance of SQL Server queries and database server as a practice too. I have been working with SQL Server for more than 8 years and I believe that many of the performance tuning concept I have mastered. However, performance tuning is not a simple subject. However there are occasions when I feel stumped, there are occasional when I am not sure what should be the next step. When I face situation where I cannot figure things out easily, it makes me most happy because I clearly see this as a learning opportunity. I have been presenting in TechEd India for last three years. This is my fourth time opportunity to present a technical session on SQL Server. Just like every other year, I decided to present something different, something which I have spend years of learning. This time, I am going to present about parallel processes. It is widely believed that more the CPU will improve performance of the server. It is true in many cases. However, there are cases when limiting the CPU usages have improved overall health of the server. I will be presenting on the subject of Parallel Processes and its effects. I have spent more than a year working on this subject only. After working on various queries on multi-CPU systems I have personally learned few things. In coming TechEd session, I am going to share my experience with parallel processes and performance tuning. 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 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. An attendee 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 Please submit your questions in the comments area and I will be for sure discussing them during my session. If I pick your question to discuss during my session, here is your gift I commit right now – SQL Server Interview Questions and Answers Book. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology Tagged: TechEd, TechEdIn

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• T-SQL Tuesday #005 : SSRS Parameters and MDX Data Sets

  - by blakmk

  Well it this weeks  T-SQL Tuesday #005  topic seems quite fitting. Having spent the past few weeks creating reports and dashboards in SSRS and SSAS 2008, I was frustrated by how difficult it is to use custom datasets to generate parameter drill downs. It also seems Reporting Services can be quite unforgiving when it comes to renaming things like datasets, so I want to share a couple of techniques that I found useful. One of the things I regularly do is to add parameters to the querys. However doing this causes Reporting Services to generate a hidden dataset and parameter name for you. One of the things I like to do is tweak these hidden datasets removing the ‘ALL’ level which is a tip I picked up from Devin Knight in his blog: There are some rules i’ve developed for myself since working with SSRS and MDX, they may not be the best or only way but they work for me. Rule 1 – Never trust the automatically generated hidden datasets Or even ANY, automatically generated MDX queries for that matter.... I’ve previously blogged about this here.   If you examine the MDX generated in the hidden dataset you will see that it generates the MDX in the context of the originiating query by building a subcube, this mean it may NOT be appropriate to use this in a subsequent query which has a different context. Make sure you always understand what is going on. Often when i’m developing a dashboard or a report there are several parameter oriented datasets that I like to manually create. It can be that I have different datasets using the same dimension but in a different context. One example of this, is that I often use a dataset for last month and a dataset for the last 6 months. Both use the same date hierarchy. However Reporting Services seems not to be too smart when it comes to generating unique datasets when working with and renaming parameters and datasets. Very often I have come across this error when it comes to refactoring parameter names and default datasets. "an item with the same key has already been added" The only way I’ve found to reliably avoid this is to obey to rule 2. Rule 2 – Follow this sequence when it comes to working with Parameters and DataSets: 1.    Create Lookup and Default Datasets in advance 2.    Create parameters (set the datasets for available and default values) 3.    Go into query and tick parameter check box 4.    On dataset properties screen, select the parameter defined earlier from the parameter value defined earlier. Rule 3 – Dont tear your hair out when you have just renamed objects and your report doesn’t build Just use XML notepad on the original report file. I found I gained a good understanding of the structure of the underlying XML document just by using XML notepad. From this you can do a search and find references of the missing object. You can also just do a wholesale search and replace (after taking a backup copy of course ;-) So I hope the above help to save the sanity of anyone who regularly works with SSRS and MDX.   @Blakmk

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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 – Monitoring SQL Server Database Transaction Log Space Growth – DBCC SQLPERF(logspace) – Puzzle for You

  - by pinaldave

  First of all – if you are going to say this is very old subject, I agree this is very (very) old subject. I believe in earlier time we used to have this only option to monitor Log Space. As new version of SQL Server released we all equipped with DMV, Performance Counters, Extended Events and much more new enhancements. However, during all this year, I have always used DBCC SQLPERF(logspace) to get the details of the logs. It may be because when I started my career I remember this command and it did what I wanted all the time. Recently I have received interesting question and I thought, I should request your help. However, before I request your help, let us see traditional usage of DBCC SQLPERF(logspace). Every time I have to get the details of the log I ran following script. Additionally, I liked to store the details of the when the log file snapshot was taken as well so I can go back and know the status log file growth. This gives me a fair estimation when the log file was growing. CREATE TABLE dbo.logSpaceUsage ( id INT IDENTITY (1,1), logDate DATETIME DEFAULT GETDATE(), databaseName SYSNAME, logSize DECIMAL(18,5), logSpaceUsed DECIMAL(18,5), [status] INT ) GO INSERT INTO dbo.logSpaceUsage (databaseName, logSize, logSpaceUsed, [status]) EXEC ('DBCC SQLPERF(logspace)') GO SELECT * FROM dbo.logSpaceUsage GO I used to record the details of log file growth every hour of the day and then we used to plot charts using reporting services (and excel in much earlier times). Well, if you look at the script above it is very simple script. Now here is the puzzle for you. Puzzle 1: Write a script based on a table which gives you the time period when there was highest growth based on the data stored in the table. Puzzle 2: Write a script based on a table which gives you the amount of the log file growth from the beginning of the table to the latest recording of the data. You may have to run above script at some interval to get the various data samples of the log file to answer above puzzles. To make things simple, I am giving you sample script with expected answers listed below for both of the puzzle. Here is the sample query for puzzle: -- This is sample query for puzzle CREATE TABLE dbo.logSpaceUsage ( id INT IDENTITY (1,1), logDate DATETIME DEFAULT GETDATE(), databaseName SYSNAME, logSize DECIMAL(18,5), logSpaceUsed DECIMAL(18,5), [status] INT ) GO INSERT INTO dbo.logSpaceUsage (databaseName, logDate, logSize, logSpaceUsed, [status]) SELECT 'SampleDB1', '2012-07-01 7:00:00.000', 5, 10, 0 UNION ALL SELECT 'SampleDB1', '2012-07-01 9:00:00.000', 16, 10, 0 UNION ALL SELECT 'SampleDB1', '2012-07-01 11:00:00.000', 9, 10, 0 UNION ALL SELECT 'SampleDB1', '2012-07-01 14:00:00.000', 18, 10, 0 UNION ALL SELECT 'SampleDB3', '2012-06-01 7:00:00.000', 5, 10, 0 UNION ALL SELECT 'SampleDB3', '2012-06-04 7:00:00.000', 15, 10, 0 UNION ALL SELECT 'SampleDB3', '2012-06-09 7:00:00.000', 25, 10, 0 GO Expected Result of Puzzle 1 You will notice that there are two entries for database SampleDB3 as there were two instances of the log file grows with the same value. Expected Result of Puzzle 2 Well, please a comment with valid answer and I will post valid answers with due credit next week. Not to mention that winners will get a surprise gift from me. 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: DBCC

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• SQLAuthority News – Feature Pack for Microsoft SQL Server 2005 SP4

  - by pinaldave

  If you are still using SQL Server 2005 – I suggest that you consider migrating to later version of the SQL Server 2008/2008 R2. Due to any reason, you wanted to continue using SQL Server 2005, I suggest that you take a look at the Feature Pack for Microsoft SQL Server 2005 SP4. There are many different tools and features available in pack, which can be very handy and can solve issues. Microsoft ADOMD.NET Microsoft Core XML Services (MSXML) 6.0 Microsoft OLEDB Provider for DB2 Microsoft SQL Server Management Pack for MOM 2005 Microsoft SQL Server 2000 PivotTable Services Microsoft SQL Server 2000 DTS Designer Components Microsoft SQL Server Native Client Microsoft SQL Server 2005 Analysis Services 9.0 OLE DB Provider Microsoft SQL Server 2005 Backward Compatibility Components Microsoft SQL Server 2005 Command Line Query Utility Microsoft SQL Server 2005 Datamining Viewer Controls Microsoft SQL Server 2005 JDBC Driver Microsoft SQL Server 2005 Management Objects Collection Microsoft SQL Server 2005 Compact Edition Microsoft SQL Server 2005 Notification Services Client Components Microsoft SQL Server 2005 Upgrade Advisor Microsoft .NET Data Provider for mySAP Business Suite, Preview Version Reporting Add-In for Microsoft Visual Web Developer 2005 Express Microsoft Exception Message Box Data Mining Managed Plug-in Algorithm API for SQL Server 2005 Microsoft SQL Server 2005 Reporting Services Add-in for Microsoft SharePoint Technologies Microsoft SQL Server 2005 Data Mining Add-ins for Microsoft Office 2007 SQL Server 2005 Performance Dashboard Reports SQL Server 2005 Best Practices Analyzer Download Feature Pack for Microsoft SQL Server 2005 SP4 Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Service Pack, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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• SQL SERVER – Find Max Worker Count using DMV – 32 Bit and 64 Bit

  - by pinaldave

  During several recent training courses, I found it very interesting that Worker Thread is not quite known to everyone despite the fact that it is a very important feature. At some point in the discussion, one of the attendees mentioned that we can double the Worker Thread if we double the CPU (add the same number of CPU that we have on current system). The same discussion has triggered this quick article. Here is the DMV which can be used to find out Max Worker Count SELECT max_workers_count FROM sys.dm_os_sys_info Let us run the above query on my system and find the results. As my system is 32 bit and I have two CPU, the Max Worker Count is displayed as 512. To address the previous discussion, adding more CPU does not necessarily double the Worker Count. In fact, the logic behind this simple principle is as follows: For x86 (32-bit) upto 4 logical processors  max worker threads = 256 For x86 (32-bit) more than 4 logical processors  max worker threads = 256 + ((# Procs – 4) * 8) For x64 (64-bit) upto 4 logical processors  max worker threads = 512 For x64 (64-bit) more than 4 logical processors  max worker threads = 512+ ((# Procs – 4) * 8) In addition to this, you can configure the Max Worker Thread by using SSMS. Go to Server Node >> Right Click and Select Property >> Select Process and modify setting under Worker Threads. According to Book On Line, the default Worker Thread settings are appropriate for most of the systems. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL System Table, SQL Tips and Tricks, T SQL, Technology Tagged: SQL DMV

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• SQL SERVER – Tricks to Comment T-SQL in SSMS – SQL in Sixty Seconds #019 – Video

  - by pinaldave

  Code commeting is the one of the most common tasks developers perform. There are two major reasons why developer comment code. 1) During Debug 2) Documenting the code. While debugging the T-SQL code I have often seen developers struggling to comment code.  They spend (or waste) more time in commenting and uncommenting  than doing actual debugging of the procedure.  When I see developer struggling to comment the code I feel little uncomfortable as commenting should be a very easy task over. Today we will see three quick method to comment T-SQL code in Query Editor. There are three different method to comment and uncomment statements in SQL Server Management Studio Using Keyboard Shortcuts Using Tool Bar Using Menu Bar Method 1: Using Keyboard Shortcuts Commenting the statement – CTRL+K, CTRL+C Commenting the statement – CTRL+K, CTRL+U Method 2: Using Tool Bar Using Tool bar buttons. (See Video) Method 3: Using Menu Bar Commenting the statement – Menu Bar >> Edit >> Advanced >> Click on Comment Selection. Unommenting the statement – Menu Bar >> Edit >> Advanced >> Click on Uncomment Selection. More on Importing CSV Data: Two Different Ways to Comment Code – Explanation and Example I encourage you to submit your ideas for SQL in Sixty Seconds. We will try to accommodate as many as we can. If we like your idea we promise to share with you educational material. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video

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• SQL SERVER – CTRL+SHIFT+] Shortcut to Select Code Between Two Parenthesis

  - by pinaldave

  Every weekend brings creative ideas and accidents brings best unknown secrets in front of us. Just a day while working with complex SQL Server code in SSMS I came across very interesting shortcut which I have never used before and instantly fell in love with it. It is totally possible that you are familiar with this but for me it was the first time and I was surprised that I did know know this short cut so far. Shortcut key is CTRL+SHIFT+]. This key can be very useful when dealing with multiple subqueries, CTE or query with multiple parentheses. When exercised this shortcut key it selects T-SQL code between two parentheses. Let us see the examples to understand the same. In each of the examples I have put the cursor at the position displayed and pressed CTRL+SHIFT+] and it has selected the code between two corresponding parentheses. Cursor position 1 Cursor position 2 Cursor position 3 If you are a developer and have to code with complex queries, you will totally appreciate that this feature can save so much of the time for development. I often remember my experience as a developer when I have lost a lot of hours to just balance parentheses. As I said yesterday I found this shortcut accidently. How many of you were aware of this feature? Is there any other useful feature you would like to share with us? Please leave a comment and if I have not covered it earlier, I will share it due credit on this blog. 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 Tagged: SQL Shortcut

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• SQL SERVER – What is Page Life Expectancy (PLE) Counter

  - by pinaldave

  During performance tuning consultation there are plenty of counters and values, I often come across. Today we will quickly talk about Page Life Expectancy counter, which is commonly known as PLE as well. You can find the value of the PLE by running following query. SELECT [object_name], [counter_name], [cntr_value] FROM sys.dm_os_performance_counters WHERE [object_name] LIKE '%Manager%' AND [counter_name] = 'Page life expectancy' The recommended value of the PLE counter is 300 seconds. I have seen on busy system this value to be as low as even 45 seconds and on unused system as high as 1250 seconds. Page Life Expectancy is number of seconds a page will stay in the buffer pool without references. In simple words, if your page stays longer in the buffer pool (area of the memory cache) your PLE is higher, leading to higher performance as every time request comes there are chances it may find its data in the cache itself instead of going to hard drive to read the data. Now check your system and post back what is this counter value for you during various time of the day. Is this counter any way relates to performance issues for your system? Note: There are various other counters which are important to discuss during the performance tuning and this counter is not everything. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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• SQLAuthority News – Author Visit to Nepal TechMela – 2 Technical Sessions

  - by pinaldave

  Microsoft MDP Nepal is going to organize a Tech Mela for the IT community of Nepal on March 29 & 30, 2010 (2066 Chaitra 16 & 17), Monday and Tuesday,  at the Russian Center for Science & Culture, Kamalpokhari, Kathmandu. The objective of the event is to enhance and exchange knowledge about Information Technology, as well as Microsoft products and technologies, with the IT community. I am very excited to attend this one-of-a-kind event in Nepal. I will be giving two presentations in the said event, which includes: 1) Become An Efficient Developer – Learn The Tricks of SQL Server Management Studio (SSMS) There are so many features in SQL Server Management Studio that we may not know or use all of them. This presentation will impart tricks and tips of SQL Server Management Studio to the event goers. This aims to make you an efficient developer by having an edge over the other developers. 2) Good, Bad and Ugly: The Story of Index Index is often considered as the sure shot tool of improving the performance of any query. Learn the basics with examples and discover the good, bad and ugly sides of Index. This session will help you efficiently write queries in future. I am very excited to attend this special event as this is the very first time I will be presenting in technical sessions in Nepal. If you are in Nepal, I strongly suggest that you go to this once-in a lifetime IT fair. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, T SQL, Technology

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• SQL SERVER – SELECT TOP Shortcut in SQL Server Management Studio (SSMS)

  - by pinaldave

  This is tool is pretty old, yet always comes as a handy tip. I had a great trip at TechEd in India. And, during one of my presentations, I was asked if there are any shortcuts to SELECT only TOP 100 records from SSMS. I immediately told him that if he explores the table in SSMS, he can just right click on it and SELECT TOP 1000 records. If he wanted only 100 records, then he could edit that 1000 to 100 by means of going to Options. Go to Options, then hover the mouse over the SQL Server Object Explorer, then proceed to Commands. Afterwards, change the Value for Select Top <n> Audit Records. After narrating the steps, he told me that he was not looking for the right click option; rather he was asking if there is any kind of keyboard shortcut for convenience’s sake. Actually, a keyboard shortcut is also possible. SQL Server Management Studio (SSMS) lets you configure the settings you want using a shortcut. Here is how you can do it. Go to Options, then to Environment. Proceed to Keyboard, and from there, configure your T-SQL with the desired keyword. Now, open SSMS New Query Window, and then click and type in any table name.  After that, just hit the shortcut you just made earlier. Doing this should display TOP 100 records in the Result window. I am sure this trick is quite old, but it is still helpful to many. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Add-On, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Find Most Expensive Queries Using DMV

  - by pinaldave

  The title of this post is what I can express here for this quick blog post. I was asked in recent query tuning consultation project, if I can share my script which I use to figure out which is the most expensive queries are running on SQL Server. This script is very basic and very simple, there are many different versions are available online. This basic script does do the job which I expect to do – find out the most expensive queries on SQL Server Box. SELECT TOP 10 SUBSTRING(qt.TEXT, (qs.statement_start_offset/2)+1, ((CASE qs.statement_end_offset WHEN -1 THEN DATALENGTH(qt.TEXT) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2)+1), qs.execution_count, qs.total_logical_reads, qs.last_logical_reads, qs.total_logical_writes, qs.last_logical_writes, qs.total_worker_time, qs.last_worker_time, qs.total_elapsed_time/1000000 total_elapsed_time_in_S, qs.last_elapsed_time/1000000 last_elapsed_time_in_S, qs.last_execution_time, qp.query_plan FROM sys.dm_exec_query_stats qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) qt CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp ORDER BY qs.total_logical_reads DESC -- logical reads -- ORDER BY qs.total_logical_writes DESC -- logical writes -- ORDER BY qs.total_worker_time DESC -- CPU time You can change the ORDER BY clause to order this table with different parameters. I invite my reader to share their scripts. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLAuthority News, SQLServer, T SQL, Technology Tagged: SQL DMV

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• SQL SERVER – Online Session on What is New in Denali – Today Online

  - by pinaldave

  I will be presenting today on subject Inside of Next Generation SQL Server – Denali online at Zeollar.com. This sessions are really fun as they are online, downloadable, and 100% demo oriented. I will be using SQL Server ‘Denali’ CTP 1 to present on the subject of What is New in Denali. The webcast will start at 12:30 PM sharp and will end at 1 PM India Time. It will be 100% demo oriented and no slides. I will be covering following topics in the session. SQL SERVER – Denali Feature – Zoom Query Editor SQL SERVER – Denali – Improvement in Startup Options SQL SERVER – Denali – Clipboard Ring – CTRL+SHIFT+V SQL SERVER – Denali – Multi-Monitor SSMS Windows SQL SERVER – Denali – Executing Stored Procedure with Result Sets SQL SERVER – Performance Improvement with of Executing Stored Procedure with Result Sets in Denali SQL SERVER – ‘Denali’ – A Simple Example of Contained Databases SQL SERVER – Denali – ObjectID in Negative – Local TempTable has Negative ObjectID SQL SERVER – Server Side Paging in SQL Server Denali – A Better Alternative SQL SERVER – Server Side Paging in SQL Server Denali Performance Comparison SQL SERVER – Denali – SEQUENCE is not IDENTITY SQL SERVER – Denali – Introduction to SEQUENCE – Simple Example of SEQUENCE If time permits we will cover few more topics as well. The session will be recorded as well. My earlier session on the Topic of Best Practices Analyzer is also available to watch online here: SQL SERVER – Video – Best Practices Analyzer using Microsoft Baseline Configuration Analyzer Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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• SQL Server – Learning SQL Server Performance: Indexing Basics – Interview of Vinod Kumar by Pinal Dave

  - by pinaldave

  Recently I just wrote a blog post on about Learning SQL Server Performance: Indexing Basics and I received lots of request that if we can share some insight into the course. Every single time when Performance is discussed, Indexes are mentioned along with it. In recent times, data and application complexity is continuously growing.  The demand for faster query response, performance, and scalability by organizations is increasing and developers and DBAs need to now write efficient code to achieve this. When we developed the course – we made sure that this course remains practical and demo heavy instead of just theories on this subject. Vinod Kumar and myself we often thought about this and realized that practical understanding of the indexes is very important. One can not master every single aspects of the index. However there are some minimum expertise one should gain if performance is one of the concern. Here is 200 seconds interview of Vinod Kumar I took right after completing the course. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology, Video

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• SQLAuthority News – Fast Track Data Warehouse 3.0 Reference Guide

  - by pinaldave

  http://msdn.microsoft.com/en-us/library/gg605238.aspx I am very excited that Fast Track Data Warehouse 3.0 reference guide has been announced. As a consultant I have always enjoyed working with Fast Track Data Warehouse project as it truly expresses the potential of the SQL Server Engine. Here is few details of the enhancement of the Fast Track Data Warehouse 3.0 reference architecture. The SQL Server Fast Track Data Warehouse initiative provides a basic methodology and concrete examples for the deployment of balanced hardware and database configuration for a data warehousing workload. Balance is measured across the key components of a SQL Server installation; storage, server, application settings, and configuration settings for each component are evaluated. Description Note FTDW 3.0 Architecture Basic component architecture for FT 3.0 based systems. New Memory Guidelines Minimum and maximum tested memory configurations by server socket count. Additional Startup Options Notes for T-834 and setting for Lock Pages in Memory. Storage Configuration RAID1+0 now standard (RAID1 was used in FT 2.0). Evaluating Fragmentation Query provided for evaluating logical fragmentation. Loading Data Additional options for CI table loads. MCR Additional detail and explanation of FTDW MCR Rating. Read white paper on fast track data warehousing. Reference: Pinal Dave (http://blog.SQLAuthority.com)   Filed under: Business Intelligence, Data Warehousing, PostADay, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, SQL White Papers, SQLAuthority News, T SQL, Technology

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• SQL SERVER – Auto Recovery File Settings in SSMS – SQL in Sixty Seconds #034 – Video

  - by pinaldave

  Every developer once in a while facing an unfortunate situation where they have not yet saved the work and their SQL Server Management Studio crashes. Well, you can minimize the loss by optimizing auto recovery settings. In this video we can see how to set the auto recovery settings. Go to SSMS >> Tools >> Options >> Environment >> AutoRecover There are two different settings: 1) Save AutoRecover Information Every Minutes This option will save the SQL Query file at certain interval. Set this option to minimum value possible to avoid loss. If you have set this value to 5, in the worst possible case, you can loose last 5 minutes of the work. 2) Keep AutoRecover Information for Days This option will preserve the AutoRecovery information for specified days. Though, I suggest in case of accident open SQL Server Management Studio right away and recover your file. Do not procrastinate this important task for future dates. Related Tips in SQL in Sixty Seconds: Manage Help Settings – CTRL + ALT + F1 SSMS 2012 Reset Keyboard Shortcuts to Default A Cool Trick – Restoring the Default SQL Server Management Studio – SSMS Color Coding SQL Server Management Studio Status Bar – SQL in Sixty Seconds #023 – Video Clear Drop Down List of Recent Connection From SQL Server Management Studio SELECT TOP Shortcut in SQL Server Management Studio (SSMS) What would you like to see in the next SQL in Sixty Seconds video? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video Tagged: Excel

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• SQL SERVER – Copy Statistics from One Server to Another Server

  - by pinaldave

  I was recently working on a performance tuning project in Dubai (yeah I was able to see the tallest tower from the window of my work place). I had a very interesting learning experience there. There was a situation where we wanted to receive the schema of original database from a certain client. However, the client was not able to provide us any data due to privacy issues. The schema was very important because without having an access to underlying data, it was a bit difficult to judge the queries etc. For example, without any primary data, all the queries are running in 0 (zero) milliseconds and all were using nested loop as there were no data to be returned. Even though we had CPU offending queries, they were not doing anything without the data in the tables. This was really a challenge as I did not have access to production server data and I could not recreate the scenarios as production without data. Well, I was confused but Ruben from Solid Quality Mentors, Spain taught me new tricks. He suggested that when table schema is generated, we can create the statistics consequently. Here is how we had done that: Once statistics is created along with the schema, without data in the table, all the queries will work as how they will work on production server. This way, without access to the data, we were able to recreate the same scenario as production server on development server. When observed at the script, you will find that the statistics were also generated along with the query. You will find statistics included in WITH STATS_STREAM clause. What a very simple and effective script. 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 Tagged: SQL Statistics, Statistics

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• SQL SERVER – Demo Script – Keeping CPU Busy

  - by pinaldave

  Recently face very interesting situation, during presentations at event, I was asked very famous questions: “My CPU is very high all the time, how can I reduce it?” This is very interesting question and there are many answers and a single blog post is not good enough to justify this subject. I presented few situation to the person who asked the question. The member of the audience who asked question came to me afterwords and asked me few detailed questions. To answer him, I quickly wrote query which simulate high CPU. Here is the script which I wrote which increased CPU from 10% to 80%. I was wondering if there is any similar script which can simulate high CPU usage. If you have share with me and I will publish with due credit. Here is my script for the same: USE AdventureWorks GO DECLARE @Flag INT SET @Flag = 1 WHILE(@Flag < 1000) BEGIN ALTER INDEX [PK_SalesOrderDetail_SalesOrderID_SalesOrderDetailID] ON [Sales].[SalesOrderDetail] REBUILD SET @Flag = @Flag + 1 END 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, T SQL, Technology

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• MySQL – Introduction to User Defined Variables

  - by Pinal Dave

  MySQL supports user defined variables to have some data that can be used later part of your query. You can save a value to a variable using a SELECT statement and later you can access its value. Unlike other RDBMSs, you do not need to declare the data type for a variable. The data type is automatically assumed when you assign a value. A value can be assigned to a variable using a SET command as shown below SET @server_type:='MySQL'; When you above command is executed, the value, MySQL is assigned to the variable called @server_type. Now you can use this variable in the later part of the code. Suppose if you want to display the value, you can use SELECT statement. SELECT @server_type; The result is MySQL. Once the value is assigned it remains for the entire session until changed by the later statements. So unlike SQL Server, you do not need to have this as part the execution code every time. (Because in SQL Server, the variables are execution scoped and dropped after the execution). You can give column name as below SELECT @server_type AS server_type; You can also SELECT statement to DECLARE and SELECT the values for a variable. SELECT @message:='Welcome to MySQL' AS MESSAGE; The result is Message -------- Welcome to MySQL You can make use of variables to effectively apply many logics. One of the useful method is to generate the row number as shown in this post MySQL – Generating Row Number for Each Row using Variable. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: MySQL, PostADay, SQL, SQL Authority, SQL Query, SQL Tips and Tricks, T SQL

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• SQL SERVER – 2000 – DBCC SQLPERF(waitstats) – Wait Type – Day 24 of 28

  - by pinaldave

  I have received many comments, email, suggestions and motivations for my current series of wait types and wait statistics. One of the questions which I keep on receiving almost every other day is whether all of the discussions I have presented so far are also applicable to SQL Server 2000. Additionally, I receive another question asking me if wait statistics matters in SQL Server 2000. If it is, then the asker wants to know how to measure wait types for SQL Server 2000. In SQL Server, you can run the following command to get a list of all the wait types: DBCC SQLPERF(waitstats) The query above will work in SQL Server 2005/2008/R2  because of backup compatibility. As you might have noticed, I have been discussing everything keeping SQL Server 2005+ in mind, but I have given little consideration on SQL Server 2000. However, I am pretty sure that most of the suggestions I have provided are applicable to SQL Server 2000. The wait types I have been discussing mostly exist in SQL Server 2000 as well. But the difference of the 2000 version is that it gets late recent releases, but it is worth it. Wait types are very essential to measure performance bottleneck. Because of this, I do not have to state that I am big fan of them just so I could identify performance bottleneck. Please read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and there is no way that I claim it to be accurate. I suggest reading Book OnLine for further clarification. All the discussion of Wait Stats in this blog is generic and varies from system to system. It is recommended that you test this on a development server before implementing it to a production server. 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, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• SQL SERVER – Capturing Wait Types and Wait Stats Information at Interval – Wait Type – Day 5 of 28

  - by pinaldave

  Earlier, I have tried to cover some important points about wait stats in detail. Here are some points that we had covered earlier. DMV related to wait stats reset when we reset SQL Server services DMV related to wait stats reset when we manually reset the wait types However, at times, there is a need of making this data persistent so that we can take a look at them later on. Sometimes, performance tuning experts do some modifications to the server and try to measure the wait stats at that point of time and after some duration. I use the following method to measure the wait stats over the time. -- Create Table CREATE TABLE [MyWaitStatTable]( [wait_type] [nvarchar](60) NOT NULL, [waiting_tasks_count] [bigint] NOT NULL, [wait_time_ms] [bigint] NOT NULL, [max_wait_time_ms] [bigint] NOT NULL, [signal_wait_time_ms] [bigint] NOT NULL, [CurrentDateTime] DATETIME NOT NULL, [Flag] INT ) GO -- Populate Table at Time 1 INSERT INTO MyWaitStatTable ([wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], [CurrentDateTime],[Flag]) SELECT [wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], GETDATE(), 1 FROM sys.dm_os_wait_stats GO ----- Desired Delay (for one hour) WAITFOR DELAY '01:00:00' -- Populate Table at Time 2 INSERT INTO MyWaitStatTable ([wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], [CurrentDateTime],[Flag]) SELECT [wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], GETDATE(), 2 FROM sys.dm_os_wait_stats GO -- Check the difference between Time 1 and Time 2 SELECT T1.wait_type, T1.wait_time_ms Original_WaitTime, T2.wait_time_ms LaterWaitTime, (T2.wait_time_ms - T1.wait_time_ms) DiffenceWaitTime FROM MyWaitStatTable T1 INNER JOIN MyWaitStatTable T2 ON T1.wait_type = T2.wait_type WHERE T2.wait_time_ms > T1.wait_time_ms AND T1.Flag = 1 AND T2.Flag = 2 ORDER BY DiffenceWaitTime DESC GO -- Clean up DROP TABLE MyWaitStatTable GO If you notice the script, I have used an additional column called flag. I use it to find out when I have captured the wait stats and then use it in my SELECT query to SELECT wait stats related to that time group. Many times, I select more than 5 or 6 different set of wait stats and I find this method very convenient to find the difference between wait stats. In a future blog post, we will talk about specific wait stats. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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