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• SQL SERVER – Guest Post – Jacob Sebastian – Filestream – Wait Types – Wait Queues – Day 22 of 28

  - by pinaldave

  Jacob Sebastian is a SQL Server MVP, Author, Speaker and Trainer. Jacob is one of the top rated expert community. Jacob wrote the book The Art of XSD – SQL Server XML Schema Collections and wrote the XML Chapter in SQL Server 2008 Bible. See his Blog | Profile. He is currently researching on the subject of Filestream and have submitted this interesting article on the very subject. What is FILESTREAM? FILESTREAM is a new feature introduced in SQL Server 2008 which provides an efficient storage and management option for BLOB data. Many applications that deal with BLOB data today stores them in the file system and stores the path to the file in the relational tables. Storing BLOB data in the file system is more efficient that storing them in the database. However, this brings up a few disadvantages as well. When the BLOB data is stored in the file system, it is hard to ensure transactional consistency between the file system data and relational data. Some applications store the BLOB data within the database to overcome the limitations mentioned earlier. This approach ensures transactional consistency between the relational data and BLOB data, but is very bad in terms of performance. FILESTREAM combines the benefits of both approaches mentioned above without the disadvantages we examined. FILESTREAM stores the BLOB data in the file system (thus takes advantage of the IO Streaming capabilities of NTFS) and ensures transactional consistency between the BLOB data in the file system and the relational data in the database. For more information on the FILESTREAM feature, visit: http://beyondrelational.com/filestream/default.aspx FILESTREAM Wait Types Since this series is on the different SQL Server wait types, let us take a look at the various wait types that are related to the FILESTREAM feature. FS_FC_RWLOCK This wait type is generated by FILESTREAM Garbage Collector. This occurs when Garbage collection is disabled prior to a backup/restore operation or when a garbage collection cycle is being executed. FS_GARBAGE_COLLECTOR_SHUTDOWN This wait type occurs when during the cleanup process of a garbage collection cycle. It indicates that that garbage collector is waiting for the cleanup tasks to be completed. FS_HEADER_RWLOCK This wait type indicates that the process is waiting for obtaining access to the FILESTREAM header file for read or write operation. The FILESTREAM header is a disk file located in the FILESTREAM data container and is named “filestream.hdr”. FS_LOGTRUNC_RWLOCK This wait type indicates that the process is trying to perform a FILESTREAM log truncation related operation. It can be either a log truncate operation or to disable log truncation prior to a backup or restore operation. FSA_FORCE_OWN_XACT This wait type occurs when a FILESTREAM file I/O operation needs to bind to the associated transaction, but the transaction is currently owned by another session. FSAGENT This wait type occurs when a FILESTREAM file I/O operation is waiting for a FILESTREAM agent resource that is being used by another file I/O operation. FSTR_CONFIG_MUTEX This wait type occurs when there is a wait for another FILESTREAM feature reconfiguration to be completed. FSTR_CONFIG_RWLOCK This wait type occurs when there is a wait to serialize access to the FILESTREAM configuration parameters. Waits and Performance System waits has got a direct relationship with the overall performance. In most cases, when waits increase the performance degrades. SQL Server documentation does not say much about how we can reduce these waits. However, following the FILESTREAM best practices will help you to improve the overall performance and reduce the wait types to a good extend. 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 Tagged: Filestream

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• SQL SERVER – Data Pages in Buffer Pool – Data Stored in Memory Cache

  - by pinaldave

  This will drop all the clean buffers so we will be able to start again from there. Now, run the following script and check the execution plan of the query. Have you ever wondered what types of data are there in your cache? During SQL Server Trainings, I am usually asked if there is any way one can know how much data in a table is stored in the memory cache? The more detailed question I usually get is if there are multiple indexes on table (and used in a query), were the data of the single table stored multiple times in the memory cache or only for a single time? Here is a query you can run to figure out what kind of data is stored in the cache. USE AdventureWorks GO SELECT COUNT(*) AS cached_pages_count, name AS BaseTableName, IndexName, IndexTypeDesc FROM sys.dm_os_buffer_descriptors AS bd INNER JOIN ( SELECT s_obj.name, s_obj.index_id, s_obj.allocation_unit_id, s_obj.OBJECT_ID, i.name IndexName, i.type_desc IndexTypeDesc FROM ( SELECT OBJECT_NAME(OBJECT_ID) AS name, index_id ,allocation_unit_id, OBJECT_ID FROM sys.allocation_units AS au INNER JOIN sys.partitions AS p ON au.container_id = p.hobt_id AND (au.type = 1 OR au.type = 3) UNION ALL SELECT OBJECT_NAME(OBJECT_ID) AS name, index_id, allocation_unit_id, OBJECT_ID FROM sys.allocation_units AS au INNER JOIN sys.partitions AS p ON au.container_id = p.partition_id AND au.type = 2 ) AS s_obj LEFT JOIN sys.indexes i ON i.index_id = s_obj.index_id AND i.OBJECT_ID = s_obj.OBJECT_ID ) AS obj ON bd.allocation_unit_id = obj.allocation_unit_id WHERE database_id = DB_ID() GROUP BY name, index_id, IndexName, IndexTypeDesc ORDER BY cached_pages_count DESC; GO Now let us run the query above and observe the output of the same. We can see in the above query that there are four columns. Cached_Pages_Count lists the pages cached in the memory. BaseTableName lists the original base table from which data pages are cached. IndexName lists the name of the index from which pages are cached. IndexTypeDesc lists the type of index. Now, let us do one more experience here. Please note that you should not run this test on a production server as it can extremely reduce the performance of the database. DBCC DROPCLEANBUFFERS This will drop all the clean buffers and we will be able to start again from there. Now run following script and check the execution plan for the same. USE AdventureWorks GO SELECT UnitPrice, ModifiedDate FROM Sales.SalesOrderDetail WHERE SalesOrderDetailID BETWEEN 1 AND 100 GO The execution plans contain the usage of two different indexes. Now, let us run the script that checks the pages cached in SQL Server. It will give us the following output. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. Let me know what you think of this article. I had a great pleasure while writing this article because I was able to write on this subject, which I like the most. In the next article, we will exactly see what data are cached and those that are not cached, using a few undocumented commands. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL DMV

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• SQLAuthority News – The Best Quotes of “Who Wrote This?” Contest

  - by pinaldave

  I am a frequent reader of Brent Ozar PLF, it is one of my favorite blogs. A recent post announced a “Who Wrote This?” contest to see if readers could tell their three contributors apart based on some writing samples. Here are my favorite lines from the sample paragraphs, from each of the three “mystery authors.” Topic 1: Working with Bad Managers Mystery Author A – “Working with bad managers means working against my own happiness, and I’ve come to learn that there’s no changing bad managers.” I love this line because, as anyone who has had a bad manager knows, often a lot of self-doubt rises up. We all have to remember that sometimes the problem is out of our control. Mystery Author B – “Mentor your manager just like you would mentor a junior DBA.” Having a bad manager can be extremely depressing, and we often feel out of control. But we all need to remember that our work is a two-way street, and that sometimes we can subtly influence those above us. Mystery Author C – “The trick to working for all bad managers is to remember that they aren’t your parent. Take charge of your career.” We all also need to learn not to play the blame game. Would you rather stay in a place where you are unhappy, or would you rather take charge of your life? I hope most people would pick the latter. Topic 2: Working with Remote Teams Mystery Author A – “Like almost anything else the key is to make sure that everyone on the team has an understanding of how and when communication will occur.” Communication is so important. I cannot over emphasize how much. And this one line captures how I feel and even communicates the idea clearly! Mystery Author B – “The key to remote team success is verifiable trust: feeling confident that invisible team members are doing the right amount of the right thing at the right time.” I think this line not only captures the key aspects of remote work – verifiable work and trust – but there were so many lines that followed that I loved and could not fit here. The whole paragraph is a list for successful remote work. Everyone could benefit from reading it. Mystery Author C – “What seems clear, precise, and specific in one time zone comes across as vague, soupy, and just plain weird in another.” You know what? I just love this description. The author is right – sometimes vague e-mails really do seem soupy and weird! Topic 3: Working with Your Nemesis Mystery Author A – “Every job is temporary, but your reputation stays with you.” Everyone needs to remember this. The workplace is meant to be a professional arena, and many people have the opinion that work is temporary and disposable. No one wants to work with co-worker like that. Mystery Author B – “Unhealthy conflict is going to lead to leaving three week old tuna fish sandwiches in someone’s desk drawer.” Sometimes humor really is the best policy! Mystery Author C – “Oh no, it’s that guy.” This might seem like a weird phrase to choose as my favorite from an entire paragraph. But the whole piece was written in the form of a story of co-workers getting drunk and plotting against a nemesis. It was too funny to overlook, but too long to post here. A must read! Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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• SQL SERVER – A Picture is Worth a Thousand Words – A Collection of Inspiring and Funny Posts by Vinod Kumar

  - by pinaldave

  One of the most popular quotes is: A picture is worth a thousand words. Working on this concept I started a series over my blog called the “Picture Post”. Rather than rambling over tons of material over text, we are trying to give you a capsule mode of the blog in a quick glance. Some of the picture posts already available over my blog are: Correlation of Ego and Work: Ego and Pride most of the times become a hindrance when we work inside a team. Take this cue, the first ever Picture post was published. Simple and easy to understand concept. Would want to say, Ego is the biggest enemy to humans. Read Original Post. Success (Perception Vs Reality): Personally, have always thought success is not something the talented achieve with the opportunity presented to them, but success is developed using the opportunity in hand now. In this fast paced world where success is pre-defined and convoluted by metrics it is hard to understand how complex it can sometimes be. So I took a stab at this concept in a simple way. Read Original Post. Doing Vs Saying: As Einstein would describe, Insanity is doing the same thing over and over again and expecting different results. Given the amount of information we get, it is difficult to keep track, learn and implement the same. If you were ever reminded of your college days, there will always be 5-6 people doing different things and we naturally try to emulate what they are doing. This could be from competitive exams GMAT, GRE, CAT, Higher-Ed, B-School hunting etc. Rather than saying you are going to do, it is best to do and then say!!! Read Original Picture Post. Your View Vs Management View: Being in the corporate world can be really demanding and we keep asking this question – “Why me?” when the performance appraisal process ends. In this post I just want to ask you one frank opinion – “Are you really self-critical in your assessments?”. If that is the case there shouldn’t be any heartburns or surprises. If you had just one thing to take back, well forget what others are getting but invest time in making yourself better because that is going to take you longer and further in your career. Read Picture Post. Blogging lifecycle for majority: I am happy and fortunate to be in this blog post because this picture post surely doesn’t apply to SQLAuthority where consistency and persistence have been the hallmark of the blog. For the majority others, who have a tendency to start a blog, get into slumber for a while and write saying they want to get back to blogging, the picture post was specifically done for them. Paradox of being someone else: It is always a dream that we want to become somebody and in this process of doing so, we become nobody. In this constant tussle of lost identity we forget to enjoy the moment that is in front of us. I just depicted this using a simple analogy of our constant struggle to get to the other side, just to realize we missed the wonderful moments. Grass is not greener on the other side, but grass is greener where we water the surface. Read Picture Post. And on the lighter side… Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – List of All the Samples Database Available to Download for FREE

  - by Pinal Dave

  It is pretty much very common to have a sample database for any database product. Different companies keep on improving their product and keep on coming up with innovation in their product. To demonstrate the capability of their new enhancements they need the sample database. Microsoft have various sample database available for free download for their SQL Server Product. I have collected them here in a single blog post. Download an AdventureWorks Database The AdventureWorks OLTP database supports standard online transaction processing scenarios for a fictitious bicycle manufacturer (Adventure Works Cycles). Scenarios include Manufacturing, Sales, Purchasing, Product Management, Contact Management, and Human Resources. Coconut Dal Coconut Dal is a lightweight data access layer, for use in projects where the Entity Framework cannot be used or Microsoft’s Enterprise Library Data Block is unsuitable. Anyone who is handwriting ADO.NET should use a library instead and Coconut Dal might be the answer.  DataBooster – Extension to ADO.NET Data Provider The dbParallel DataBooster library is a high-performance extension to ADO.NET Data Provider, includes two aspects: 1) A slimmed down API encapsulation which simplified the most common data access operations (DbConnection -> DbCommand -> DbParameter -> DbDataReader) into a single class DbAccess, to help application with a clean DAL, avoid over-packing and redundant-copy of data transfer. 2) A booster for writing mass data onto database. Base on a rational utilization of database concurrency and a effective utilization of network bandwidth. Tabular AMO 2012 The sample is made of two project parts. The first part is a library of functions to manage tabular models -AMO2Tabular V2-. The second part is a sample to build a tabular model -AdventureWorks Tabular AMO 2012- using the AMO2Tabular library; the created model is similar to the ‘AdventureWorks Tabular Model 2012. SQL Server Analysis Services Product Samples SQL Server Analysis Services provides, a unified and integrated view of all your business data as the foundation for all of your traditional reporting, online analytical processing (OLAP) analysis, Key Performance Indicator (KPI) scorecards, and data mining. Analysis Services Samples for SQL Server 2008 R2 This release is dedicated to the samples that ship for Microsoft SQL Server 2008R2. For many of these samples you will also need to download the AdventureWorks family of databases. SQL Server Reporting Services Product Samples This project contains Reporting Services samples released with Microsoft SQL Server product. These samples are in the following five categories: Application Samples, Extension Samples, Model Samples, Report Samples, and Script Samples. If you are interested in contributing Reporting Services samples, please let us know by posting in the developers’ forum. Reporting Services Samples for SQL Server 2008 R2 This release is dedicated to the samples that ship for Microsoft SQL Server 2008 R2 PCU1. For many of these samples you will also need to download the AdventureWorks family of databases. SQL Server Integration Services Product Samples This project contains Integration Services samples released with Microsoft SQL Server product. These samples are in the following two categories: Package Samples and Programming Samples. If you are interested in contributing Integration Services samples, please let us know by posting in the developers’ forum. Integration Services Samples for SQL Server 2008 R2 This release is dedicated to the samples that ship for Microsoft SQL Server 2008R2. For many of these samples you will also need to download the AdventureWorks family of databases. Windows Azure SQL Reporting Admin Sample The SQLReportingAdmin sample for Windows Azure SQL Reporting demonstrates the usage of SQL Reporting APIs, and manages (add/update/delete) permissions of SQL Reporting users. Windows Azure SQL Reporting ReportViewer-SOAP API usage sample These sample projects demonstrate how to embed a Microsoft ReportViewer control that points to reports hosted on SQL Reporting report servers and how to use SQL Reporting SOAP APIs in your Windows Azure Web application. Enterprise Library 5.0 – Integration Pack for Windows Azure This NuGet package contains a zip file with the source code for the Enterprise Library Integration Pack for Windows Azure.  Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Sample Database

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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 – What is SSRS and Why SSRS is asked for in many Job Opening?

  - by Pinal Dave

  This example is from the Beginning SSRS by Kathi Kellenberger. Supporting files are available with a free download from the www.Joes2Pros.com web site. This will be a 5 day blog post in getting started with SSRS. Today will show the importance of SSRS in the business. Why is SSRS asked for in so many job openings? If you talk to an SSRS expert it’s very clear to them exactly why companies really need this invention and how it saves time and adds business value. You don’t have to be an SSRS expert to know its value or to start using it. For example you don’t have to be an airline pilot to know the usefulness of modern transportation. Even the people who don’t know how to run SSRS but need the reports can tell you why that is needed. This blog post will go into why SSRS is an important invention by showing how it improves the usage of information in your company. Before SSRS there has always been a need for a company to benefit from the use of its own information. Excel spreadsheets have been a popular way to do this for a long time. With SSRS you can still use this solution and gain many other options too. A friend of mine told me a story about doing database work in the 90s for a major company and how he wished SSRS was available back then. The Vice President of the marketing channel would often come to him just before an important meeting with the board of directors. He often needed to show how certain product sales were performing over time. All this information was in the database so it was my friend’s job to get the information out and organized into a medium the VP could use. This medium was usually Excel. The VP often had meetings all over the world where he showcased this Excel report. The solution to get the VP to him anywhere he was in the world was an Excel file attached to an e-mail. This worked pretty well but with some drawbacks. One time my friend sent the wrong file in the e-mail. A few minutes later my friend realized his mistake and sent another frantic e-mail to VP. This one was saying to ignore the last e-mail and use this newer one. Would the VP see the correct e-mail in time? If SSRS had been available, my friend could have created a solution that let the VP run the report any time he wished. The report could have been published to the company intranet where the VP could run it from any of the offices he happened to be traveling to that month. There is a fair amount of work up front to develop and publish the report, but once that work is completed, the report can be reused as many times as needed. My friend could even be on vacation for the first day of the monthly and the VP can get his real-time report. Not only could the report show the most recent data, the VP could choose to view reports of previous months with just a few clicks. The deployed SSRS is user friendly, and can also be configured to protect reports from being run by the wrong people. Tomorrow’s Post Tomorrow’s blog post will show how to know if you already have SSRS installed. If you want to learn SSRS in easy to simple words – I strongly recommend you to get Beginning SSRS book from Joes 2 Pros. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Reporting Services, SSRS

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• SQL SERVER – Vacation, Travel and Study – A New Concept

  - by pinaldave

  Quite often when developers go to training sessions they either find it very boring because of study or great because they treat it as a vacation. There should be a perfect balance between study and extra activities. Studying is Boring Studying is very hard. Nobody likes to study, very few people are going to list “studying” as one of their favorite hobbies.  Already my young daughter knows she doesn’t want to study, and I don’t want to either.  If you read my blog regularly you know that I am always saying that we need to be students for life.  However, all philosophy aside, if you are put in a room with an instructor to study for eight hours a day, you are going to feel bored, uncomfortable, and unhappy.  I was a trainer myself, and I understand that all-day study sessions are no fun – even for the trainer.  I always tried to be entertaining, but even eight hours of jokes and laughter is tiresome.  Eight hours at a comedy club would be boring after a little while – and if we can’t even enjoy fun stuff for eight hours straight, how can we expect to study for eight hours straight? Studying for Career or Certification Even those who have advanced degrees and went to college for years, or even decades, find studying hard.  There is a difference between studying for a career and studying for a certification.  At least to get a degree there is a variety of subjects, with labs, exams, and practice problems to make things more interesting.  You can also choose your major and what you want to spend your time studying.  For certification you do not have this luxury.  You have to learn and memorize specific parts, and there is no option to change your major if you don’t like it.  Your option is to gain your certification, or fail.  Many people will find that last option unacceptable. Studying at Vacation We have established: eight hours of uninterrupted study is boring.  That is why I am so excited about what my very good friend is doing with Koenig Solutions.  His whole goal was to make classes that are intensive but not in a traditional format.  He adds in aspects of the vacation.  It is true that you will study and sit with instructors for six or eight hours a day, but in the mornings and evenings you can go out and see the sights in exotic locations.  He has chosen the locations for his training courses for their proximity to tourist attractions like the Himalayas, the Taj Mahal, and Goa, India’s most popular resort town.  Every location has access to great experiences like river rafting, safari tours, or meditation.  There are five locations to choose from: Dehli, Dehradun, Shimla (close to the Himalayas), Goa Beach, and Dubai.  After a day of classes and hours of sight-seeing, you will be more than ready to return to campus tired and ready to study.  This is the kind of study I can do! My friend’s point is that studying and fun can still go hand-in-hand.  How many times have we heard a professor say this?  But this time it is true.  There is great fun in learning in exotic locations.  If you want to travel in India and are interested in also taking the opportunity to learn something, let Koenig Solutions know. 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 – DMV – sys.dm_os_wait_stats Explanation – Wait Type – Day 3 of 28

  - by pinaldave

  The key Dynamic Management View (DMV) that helps us to understand wait stats is sys.dm_os_wait_stats; this DMV gives us all the information that we need to know regarding wait stats. However, the interpretation is left to us. This is a challenge as understanding wait stats can often be quite tricky. Anyway, we will cover few wait stats in one of the future articles. Today we will go over the basic understanding of the DMV. The Official Book OnLine Reference for DMV is over here: sys.dm_os_wait_stats. I suggest you all to refer this for all the accuracy. Following is a statement from the online book: “Specific types of wait times during query execution can indicate bottlenecks or stall points within the query. Similarly, high wait times, or wait counts server wide can indicate bottlenecks or hot spots in interaction query interactions within the server instance.” This is the statement which has inspired me to write this series. Let us first run the following statement from DMV. SELECT * FROM sys.dm_os_wait_stats ORDER BY wait_time_ms DESC GO Above statement will show us few of the columns. Here it is quick explanation of each of the column. wait_type – this is the name of the wait type. There can be three different kinds of wait types – resource, queue and external. waiting_tasks_count – this incremental counter is a good indication of frequent the wait is happening. If this number is very high, it is good indication for us to investigate that particular wait type. It is quite possible that the wait time is considerably low, but the frequency of the wait is much high. wait_time_ms – this is total wait accumulated for any type of wait. This is the total wait time and includes singal_wait_time_ms. max_wait_time_ms – this indicates the maximum wait type ever occurred for that particular wait type. Using this, one can estimate the intensity of the wait type in past. Again, it is not necessary that this max wait time will occur every time; so do not over invest yourself here. signal_wait_time_ms – this is the wait time when thread is marked as runnable and it gets to the running state. If the runnable queue is very long, you will find that this wait time becomes high. Additionally, please note that this DMV does not show current wait type or wait stats. This is cumulative view of the all the wait stats since server (instance) restarted or wait stats have been cleared. In future blog post, we will also cover two more DMVs which can be helpful to identify wait-related issues. ?sys.dm_os_waiting_tasks sys.dm_exec_requests 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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• SQL SERVER – Top 10 “Ease of Use” Features of expressor Studio

  - by pinaldave

  expressor Studio is new data integration platform that is being marketed as the most easy to use tool of its kind.  But “easy to use” can be a relative term – an expert can find a very complex system easy, but a beginner might be stumped.  A recent article online discussed exactly what makes expressor Studio so easy use, and here is my view on this subject. Simple Installation There is one pop-up for one .exe file, and nothing more.  You can’t get much simpler than this.  It is also in the familiar Windows design, so there should be no surprises. No 3rd party software dependency Have you ever tried to download software, only to be slowed down by the need to download a compatible system to run the program, and another to read the user manual, and so on?  expressor Studio was designed specifically to avoid this problem. Microsoft Office Like Ribbon Bar and Menus As mentioned before, everything is in the familiar Windows design, from the pop up windows to the tool bars and menus.  There should be no learning curve for using this program, or even simply trying to navigate around a new system. General Development Design Interface This software has been designed to be simple and straightforward.  Projects can be arranged in a simple “tree” design, that is totally collapsible and can easy be added to or “trimmed” with a click of a button.  It was meant to be logical and easy to follow. Integrated Contextual Help This is a fancy way of saying that you can practically yell “help!” if you do get stuck on something.  Solving a problem is as simple as highlighting and hitting F1 for contextual help. Visual Indicators and Messages Wouldn’t it be nice to know exactly where something has gone wrong before trying to complete a project.  expressor Studio has a built in system to catch mistakes and highlight them in a bright color, flash a warning message, and even disable functions before you can continue – and possibly lose hours of work. Property Inputs and Selectors Every operator will have a list of requirements that need to be filled in.  But don’t worry; you won’t have to make stuff up to fill in the boxes.  Each one will have a drop-down menu with options to choose from – but not too many as to be confusing. Connection Wizards Configuring connections can be the hardest part of a project.  But not with the expressor Studioconnection wizard.  A familiar, Windows-style menu will walk you through connections so quickly you’ll forget what trouble it used to be. Templates With large, complex projects, a majority of your time is often spent simply setting up the files and inputting data.  But expressor Studio allows you to create one file and then save it as a template, saving you hours of boring data input. Extension Manager Let’s say that you need a little more functionality or some new features on your program. A lot of software requires you to download complex plug-ins that need to be decompressed and installed.  However, expressor Studio has extended its system to an Extension Manager, which allows for quick and easy installation of the functionality you need, without the need to download and decompress. 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

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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 – SafePeak “Logon Trigger” Feature for Managing Data Access

  - by pinaldave

  Lately I received an interesting question about the abilities of SafePeak for SQL Server acceleration software: Q: “I would like to use SafePeak to make my CRM application faster. It is an application we bought from some vendor, after a while it became slow and we can’t reprogram it. SafePeak automated caching sounds like an easy and good solution for us. But, in my application there are many servers and different other applications services that address its main database, and some even change data, and I feel that there is a chance that some servers that during the connection process we may miss some. Is there a way to ensure that SafePeak will be aware of all connections to the SQL Server, so its cache will remain intact?” Interesting question, as I remember that SafePeak (http://www.safepeak.com/Product/SafePeak-Overview) likes that all traffic to the database will go thru it. I decided to check out the features of SafePeak latest version (2.1) and seek for an answer there. A: Indeed I found SafePeak has a feature they call “Logon Trigger” and is designed for that purpose. It is located in the user interface, under: Settings -> SQL instances management  ->  [your instance]  ->  [Logon Trigger] tab. From here you activate / deactivate it and control a white-list of enabled server IPs and Login names that SafePeak will ignore them. Click to Enlarge After activation of the “logon trigger” Safepeak server is notified by the SQL Server itself on each new opened connection. Safepeak monitors those connections and decides if there is something to do with them or not. On a typical installation SafePeak likes all application and users connections to go via SafePeak – this way it knows about data and schema updates immediately (real time). With activation of the safepeak “logon trigger”  a special CLR trigger is deployed on the SQL server and notifies Safepeak on any connection that has not arrived via SafePeak. In such cases Safepeak can act to clear and lock the cache or to ignore it. This feature enables to make sure SafePeak will be aware of all connections so SafePeak cache will maintain exactly correct all times. So even if a user, like a DBA will connect to the SQL Server not via SafePeak, SafePeak will know about it and take actions. The notification does not impact the work of that connection, the user or application still continue to do whatever they planned to do. Note: I found that activation of logon trigger in SafePeak requires that SafePeak SQL login will have the next permissions: 1) CONTROL SERVER; 2) VIEW SERVER STATE; 3) And the SQL Server instance is CLR enabled; Seeing SafePeak in action, I can say SafePeak brings fantastic resource for those who seek to get performance for SQL Server critical apps. SafePeak promises to accelerate SQL Server applications in just several hours of installation, automatic learning and some optimization configuration (no code changes!!!). If better application and database performance means better business to you – I suggest you to download and try SafePeak. The solution of SafePeak is indeed unique, and the questions I receive are very interesting. Have any more questions on SafePeak? Please leave your question as a comment and I will try to get an answer for you. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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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 – Quick Start with Admin Sections of NuoDB – Manage NuoDB Database

  - by Pinal Dave

  In the yesterday’s blog post we have seen that it is extremely easy to install the NuoDB database on your local machine. Now that the application is properly set up, let us explore NuoDB a bit more and get you familiar with the how it works and what the important areas of the NuoDB are that you should learn. As we have already installed NuoDB, now we will quickly start with two of the important areas in NuoDB: 1) Admin and 2) Explorer. In this blog post I will explore how the Admin Section of the NuoDB Console works.  In the next blog post we will learn how the Explorer Section works. Let us go to the NuoDB Console by typing the following URL in your browser: http://localhost:8080/ It will bring you to the following screen: On this screen you can see a big Start QuickStart button. Click on the button and it will bring you to following screen. On this screen you will find very important information about Domain and Database Settings. It is our habit that we do not read what is written on the screen and keep on clicking on continue without reading. While we are familiar with most wizards, we can often miss the very important message on the screen. Please note the information of Domain Settings and Database Settings from the following screen before clicking on Create Database. Domain Settings User: quickstart Password: quickstart Database Settings User: dba Password: goalie Database: test Schema: HOCKEY Once you click on the Create Database button it will immediately start creating sample database. First, it will start a Storage Manager and right after that it will start a Transaction Engine. Once the engine is up, it will Create a Schema and Sample Data. On the success of the creating the sample database it will show the following screen. Now is the time where we can explore the NuoDB Admin or NuoDB Explorer. If you click on Admin, it will first show following login screen. Enter for the username “domain” and for the password “bird”. Alternatively you can enter “quickstart”  twice for username and password.  It works as too. Once you enter into the Admin Section, on the left side you can see information about NuoDB and Admin Console and on the right side you can see the domain overview area. From this Administrative section you can do any of the following tasks: Create a view of the entire domain Add and remove databases Start and stop NuoDB Transaction Engines and Storage Managers Monitor transaction across all the NuoDB databases On the right side of the Admin Section we can see various information about a particular NuoDB domain. You can quickly view various alerts, find out information about the number of host machines that are provisioned for the domain, and see the number of databases and processes that are running in the domain. If you click on the “1 host” link you will be able to see various processes, CPU usage and other information. In the Processes Section you can see that there are two different types of processes. The first process (where you can see the floppy drive icon) represents a running Storage Manager process and the second process a running Transaction Engine process. You can click on the links for the Storage Manager and Transaction Engine to see further statistical details right down to the last byte of the data. There are various charts available for analysis as well. I think the product is quite mature and the user can add different monitor charts to the Admin section. Additionally, the Admin section is the place where you can create and manage new databases. I hope today’s tutorial gives you enough confidence that you can try out NuoDB and checkout various administrative activities with the database. I am personally impressed with their dashboard related to various counters. For more information about how the NuoDB architecture works and what a Storage Manager or Transaction Engine does, check out this short video with NuoDB CTO Seth Proctor:  In the next blog post, we will try out the Explorer section of NuoDB, which allows us to run SQL queries and write SQL code.  Meanwhile, I strongly suggest you download and install NuoDB and get yourself familiar with the product. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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• SQL SERVER – MSQL_XP – Wait Type – Day 20 of 28

  - by pinaldave

  In this blog post, I am going to discuss something from my field experience. While consultation, I have seen various wait typed, but one of my customers who has been using SQL Server for all his operations had an interesting issue with a particular wait type. Our customer had more than 100+ SQL Server instances running and the whole server had MSSQL_XP wait type as the most number of wait types. While running sp_who2 and other diagnosis queries, I could not immediately figure out what the issue was because the query with that kind of wait type was nowhere to be found. After a day of research, I was relieved that the solution was very easy to figure out. Let us continue discussing this wait type. From Book On-Line: ?MSQL_XP occurs when a task is waiting for an extended stored procedure to end. SQL Server uses this wait state to detect potential MARS application deadlocks. The wait stops when the extended stored procedure call ends. MSQL_XP Explanation: This wait type is created because of the extended stored procedure. Extended Stored Procedures are executed within SQL Server; however, SQL Server has no control over them. Unless you know what the code for the extended stored procedure is and what it is doing, it is impossible to understand why this wait type is coming up. Reducing MSQL_XP wait: As discussed, it is hard to understand the Extended Stored Procedure if the code for it is not available. In the scenario described at the beginning of this post, our client was using third-party backup tool. The third-party backup tool was using Extended Stored Procedure. After we learned that this wait type was coming from the extended stored procedure of the backup tool they were using, we contacted the tech team of its vendor. The vendor admitted that the code was not optimal at some places, and within that day they had provided the patch. Once the updated version was installed, the issue on this wait type disappeared. As viewed in the wait statistics of all the 100+ SQL Server, there was no more MSSQL_XP wait type found. In simpler terms, you must first identify which Extended Stored Procedure is creating the wait type of MSSQL_XP and see if you can get in touch with the creator of the SP so you can help them optimize the code. If you have encountered this MSSQL_XP wait type, I encourage all of you to write how you managed it. Please do not mention the name of the vendor in your comment as I will not approve it. The focus of this blog post is to understand the wait types; not talk about others. 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 Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• SQL SERVER – DQS Error – Cannot connect to server – A .NET Framework error occurred during execution of user-defined routine or aggregate “SetDataQualitySessions” – SetDataQualitySessionPhaseTwo

  - by pinaldave

  Earlier I wrote a blog post about how to install DQS in SQL Server 2012. Today I decided to write a second part of this series where I explain how to use DQS, however, as soon as I started the DQS client, I encountered an error that will not let me pass through and connect with DQS client. It was a bit strange to me as everything was functioning very well when I left it last time.  The error was very big but here are the first few words of it. Cannot connect to server. A .NET Framework error occurred during execution of user-defined routine or aggregate “SetDataQualitySessions”: System.Data.SqlClient.SqlException (0×80131904): A .NET Framework error occurred during execution of user-defined routine or aggregate “SetDataQualitySessionPhaseTwo”: The error continues – here is the quick screenshot of the error. As my initial attempts could not fix the error I decided to search online and I finally received a wonderful solution from Microsoft Site. The error has happened due to latest update I had installed on .NET Framework 4. There was a  mismatch between the Module Version IDs (MVIDs) of the SQL Common Language Runtime (SQLCLR) assemblies in the SQL Server 2012 database and the Global Assembly Cache (GAC). This mismatch was to be resolved for the DQS to work properly. The workaround is specified here in detail. Scroll to subtopic 4.23 Some .NET Framework 4 Updates Might Cause DQS to Fail. The script was very much straight forward. Here are the few things to not to miss while applying workaround. Make sure DQS client is properly closed The NETAssemblies is based on your OS. NETAssemblies for 64 bit machine – which is my machine is “c:\windows\Microsoft.NET\Framework64\v4.0.30319″. If you have Winodws installed on any other drive other than c:\windows do not forget to change that in the above path. Additionally if you have 32 bit version installed on c:\windows you should use path as ”c:\windows\Microsoft.NET\Framework\v4.0.30319″ Make sure that you execute the script specified in 4.23 sections in this article in the database DQS_MAIN. Do not run this in the master database as this will not fix your error. Do not forget to restart your SQL Services once above script has been executed. Once you open the client it will work this time. Here is the script which I have bit modified from original script. I strongly suggest that you use original script mentioned 4.23 sections. However, this one is customized my own machine. /* Original source: http://bit.ly/PXX4NE (Technet) Modifications: -- Added Database context -- Added environment variable @NETAssemblies -- Main script modified to use @NETAssemblies */ USE DQS_MAIN GO BEGIN -- Set your environment variable -- assumption - Windows is installed in c:\windows folder DECLARE @NETAssemblies NVARCHAR(200) -- For 64 bit uncomment following line SET @NETAssemblies = 'c:\windows\Microsoft.NET\Framework64\v4.0.30319\' -- For 32 bit uncomment following line -- SET @NETAssemblies = 'c:\windows\Microsoft.NET\Framework\v4.0.30319\' DECLARE @AssemblyName NVARCHAR(200), @RefreshCmd NVARCHAR(200), @ErrMsg NVARCHAR(200) DECLARE ASSEMBLY_CURSOR CURSOR FOR SELECT name AS NAME FROM sys.assemblies WHERE name NOT LIKE '%ssdqs%' AND name NOT LIKE '%microsoft.sqlserver.types%' AND name NOT LIKE '%practices%' AND name NOT LIKE '%office%' AND name NOT LIKE '%stdole%' AND name NOT LIKE '%Microsoft.Vbe.Interop%' OPEN ASSEMBLY_CURSOR FETCH NEXT FROM ASSEMBLY_CURSOR INTO @AssemblyName WHILE @@FETCH_STATUS = 0 BEGIN BEGIN TRY SET @RefreshCmd = 'ALTER ASSEMBLY [' + @AssemblyName + '] FROM ''' + @NETAssemblies + @AssemblyName + '.dll' + ''' WITH PERMISSION_SET = UNSAFE' EXEC sp_executesql @RefreshCmd PRINT 'Successfully upgraded assembly ''' + @AssemblyName + '''' END TRY BEGIN CATCH IF ERROR_NUMBER() != 6285 BEGIN SET @ErrMsg = ERROR_MESSAGE() PRINT 'Failed refreshing assembly ' + @AssemblyName + '. Error message: ' + @ErrMsg END END CATCH FETCH NEXT FROM ASSEMBLY_CURSOR INTO @AssemblyName END CLOSE ASSEMBLY_CURSOR DEALLOCATE ASSEMBLY_CURSOR END GO 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 – Weekend Project – Experimenting with ACID Transactions, SQL Compliant, Elastically Scalable Database

  - by pinaldave

  Database technology is huge and big world. I like to explore always beyond what I know and share the learning. Weekend is the best time when I sit around download random software on my machine which I like to call as a lab machine (it is a pretty old laptop, hardly a quality as lab machine) and experiment it. There are so many free betas available for download that it’s hard to keep track and even harder to find the time to play with very many of them.  This blog is about one you shouldn’t miss if you are interested in the learning various relational databases. NuoDB just released their Beta 7.  I had already downloaded their Beta 6 and yesterday did the same for 7.   My impression is that they are onto something very very interesting.  In fact, it might be something really promising in terms of database elasticity, scale and operational cost reduction. The folks at NuoDB say they are working on the world’s first “emergent” database which they tout as a brand new transitional database that is intended to dramatically change what’s possible with OLTP.  It is SQL compliant, guarantees ACID transactions, yet scales elastically on heterogeneous and decentralized cloud-based resources. Interesting note for sure, making me explore more. Based on what I’ve seen so far, they are solving the architectural challenge that exists between elastic, cloud-based compute infrastructures designed to scale out in response to workload requirements versus the traditional relational database management system’s architecture of central control. Here’s my experience with the NuoDB Beta 6 so far: First they pretty much threw away all the features you’d associate with existing RDBMS architectures except the SQL and ACID transactions which they were smart to keep.  It looks like they have incorporated a number of the big ideas from various algorithms, systems and techniques to achieve maximum DB scalability. From a user’s perspective, the NuoDB Beta software behaves like any other traditional SQL database and seems to offer all the benefits users have come to expect from standards-based SQL solutions. One of the interesting feature is that one can run a transactional node and a storage node on my Windows laptop as well on other platforms – indeed interesting for sure. It’s quite amazing to see a database elastically scale across machine boundaries. So, one of the basic NuoDB concepts is that as you need to scale out, you can easily use more inexpensive hardware when/where you need it.  This is unlike what we have traditionally done to scale a database for an application – we replace the hardware with something more powerful (faster CPU and Disks). This is where I started to feel like NuoDB is on to something that has the potential to elastically scale on commodity hardware while reducing operational expense for a big OLTP database to a degree we’ve never seen before. NuoDB is able to fully leverage the cloud in an asynchronous and highly decentralized manner – while providing both SQL compliance and ACID transactions. Basically what NuoDB is doing is so new that it is all hard to believe until you’ve experienced it in action.  I will keep you up to date as I test the NuoDB Beta 7 but if you are developing a web-scale application or have an on-premise app you are thinking of moving to the cloud, testing this beta is worth your time. If you do try it, let me know what you think.  Before I say anything more, I am going to do more experiments and more test on this product and compare it with other existing similar products. For me it was a weekend worth spent on learning something new. I encourage you to download Beta 7 version and share your opinions here. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQLAuthority News – Top 5 Latest Microsoft Certifications of 2013 – Guest Post

  - by Pinal Dave

  With the IT job market getting more and more competent by the day, certifications are a must for anyone who wishes to get a strong foothold in the industry. Microsoft community comes up with regular updates and enhancements in its existing products to keep up with the rapidly evolving requirements of the ICT industry. We bring you a list of five latest Microsoft certifications that you must consider acquiring this year. MCSE: SharePoint Learn all about Windows Server 2012 and Microsoft SharePoint 2013, which brings an advanced set of features to the fore in this latest version. It introduces new capabilities for business intelligence, social media, branding, search, identity management, mobile device among other features. Enjoy a great user experience with sharing and collaboration in community forum, within a pixel-perfect SharePoint website. Data connectivity and business intelligence tools allow users to process and access data, analyze reports, share and collaborate with each other more conveniently. Microsoft Specialist: Microsoft Project 2013 The only project management system that works seamlessly with other applications and cloud solutions of Microsoft, MS Project 2013 offers more than what meets the eye.  It provides for easier management and monitoring of projects so that users can ensure timely delivery while improving the productivity significantly. So keep all your projects on track and collaborate with your team like never before with this enhanced release! This one’s a must for all project managers. MCSE Messaging Another one of Microsoft gems is its messaging environment which has also launched the latest release Microsoft Exchange Server 2013. Messaging administrators can take up this training and validate their expertise in Unified Messaging, Exchange Online, PowerShell and Virtualization strategies, through MCSE Messaging certification in Exchange Server. If you wish to enhance productivity and data security of your organization while being flexible and extremely efficient, this is the right certification for you. MCSE Communication An enterprise can function optimally on the strength of its information flow and communication systems. With Lync Server 2013, you can introduce a whole new world of unified communications which consists of audio/video conferencing, dial-in, Persistent Chat, instant chat, and EDGE services in your organization. Utilize IT to serve and support business objectives by mastering this UC technology with this latest MCSE Communication course on using Microsoft Lync Server 2013. MCSE: SQL Server 2012 BI Platform The decision making process is largely influenced by underlying enterprise information used by the management for business intelligence. Therefore, a robust business intelligence platform that anchors enterprise IT and transform it to operational efficiencies is the need of the hour. SQL Server 2012 BI Platform certification helps professionals implement, manage and maintain a BI database infrastructure effectively. IT professionals with BI skills are highly sought after these days. MCSD: Windows Store Apps A Microsoft Certified Solutions Developer certification in Windows Store Apps validates your potential in designing interactive apps. Learn The Essentials of Developing Windows Store Apps using HTML5 and JavaScript and establish yourself as an ace developer capable of creating fast and fluid Metro style apps for Windows 8 that are accessible on a variety of devices. You can also go ahead and Learn Essentials of Developing Windows Store Apps using C# mode if you’re already familiar and working with C# programming language. Hence the developers are free to choose their own favorite development stream which opens doors for them to get ready for the latest and exciting application development platform called Windows store apps. Software developers with these skills are in great demand in the industry today. In order to continue being competitive in your respective fields, it is imperative that IT personnel update their knowledge on a regular basis. Certifications are a means to achieve this goal. Not considered to be an optional pre-requisite anymore, major IT certifications such as these are now essential to stay afloat in a cut-throat industry where technologies change on a daily basis. This blog is written by Aruneet Anand of Koenig Solutions. Koenig Solutions does training for all of the above courses. For more information, visit the website. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology Tagged: Microsoft Certifications

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• SQL SERVER – How to Ignore Columnstore Index Usage in Query

  - by pinaldave

  Earlier I wrote about SQL SERVER – Fundamentals of Columnstore Index and very first question I received in email was as following. “We are using SQL Server 2012 CTP3 and so far so good. In our data warehouse solution we have created 1 non-clustered columnstore index on our large fact table. We have very unique situation but your article did not cover it. We are running few queries on our fact table which is working very efficiently but there is one query which earlier was running very fine but after creating this non-clustered columnstore index this query is running very slow. We dropped the columnstore index and suddenly this one query is running fast but other queries which were benefited by this columnstore index it is running slow. Any workaround in this situation?” In summary the question in simple words “How can we ignore using columnstore index in selective queries?” Very interesting question – you can use I can understand there may be the cases when columnstore index is not ideal and needs to be ignored the same. You can use the query hint IGNORE_NONCLUSTERED_COLUMNSTORE_INDEX to ignore the columnstore index. SQL Server Engine will use any other index which is best after ignoring the columnstore index. Here is the quick script to prove the same. We will first create sample database and then create columnstore index on the same. Once columnstore index is created we will write simple query. This query will use columnstore index. We will then show the usage of the query hint. USE AdventureWorks GO -- Create New Table CREATE TABLE [dbo].[MySalesOrderDetail]( [SalesOrderID] [int] NOT NULL, [SalesOrderDetailID] [int] NOT NULL, [CarrierTrackingNumber] [nvarchar](25) NULL, [OrderQty] [smallint] NOT NULL, [ProductID] [int] NOT NULL, [SpecialOfferID] [int] NOT NULL, [UnitPrice] [money] NOT NULL, [UnitPriceDiscount] [money] NOT NULL, [LineTotal] [numeric](38, 6) NOT NULL, [rowguid] [uniqueidentifier] NOT NULL, [ModifiedDate] [datetime] NOT NULL ) ON [PRIMARY] GO -- Create clustered index CREATE CLUSTERED INDEX [CL_MySalesOrderDetail] ON [dbo].[MySalesOrderDetail] ( [SalesOrderDetailID]) GO -- Create Sample Data Table -- WARNING: This Query may run upto 2-10 minutes based on your systems resources INSERT INTO [dbo].[MySalesOrderDetail] SELECT S1.* FROM Sales.SalesOrderDetail S1 GO 100 -- Create ColumnStore Index CREATE NONCLUSTERED COLUMNSTORE INDEX [IX_MySalesOrderDetail_ColumnStore] ON [MySalesOrderDetail] (UnitPrice, OrderQty, ProductID) GO Now we have created columnstore index so if we run following query it will use for sure the same index. -- Select Table with regular Index SELECT ProductID, SUM(UnitPrice) SumUnitPrice, AVG(UnitPrice) AvgUnitPrice, SUM(OrderQty) SumOrderQty, AVG(OrderQty) AvgOrderQty FROM [dbo].[MySalesOrderDetail] GROUP BY ProductID ORDER BY ProductID GO We can specify Query Hint IGNORE_NONCLUSTERED_COLUMNSTORE_INDEX as described in following query and it will not use columnstore index. -- Select Table with regular Index SELECT ProductID, SUM(UnitPrice) SumUnitPrice, AVG(UnitPrice) AvgUnitPrice, SUM(OrderQty) SumOrderQty, AVG(OrderQty) AvgOrderQty FROM [dbo].[MySalesOrderDetail] GROUP BY ProductID ORDER BY ProductID OPTION (IGNORE_NONCLUSTERED_COLUMNSTORE_INDEX) GO Let us clean up the database. -- Cleanup DROP INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] GO TRUNCATE TABLE dbo.MySalesOrderDetail GO DROP TABLE dbo.MySalesOrderDetail GO Again, make sure that you use hint sparingly and understanding the proper implication of the same. Make sure that you test it with and without hint and select the best option after review of your administrator. Here is the question for you – have you started to use SQL Server 2012 for your validation and development (not on production)? It will be interesting to know the answer. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Sends backups to a Network Folder, FTP Server, Dropbox, Google Drive or Amazon S3

  - by pinaldave

  Let me tell you about one of the most useful SQL tools that every DBA should use – it is SQLBackupAndFTP. I have been using this tool since 2009 – and it is the first program I install on a SQL server. Download a free version, 1 minute configuration and your daily backups are safe in the cloud. In summary, SQLBackupAndFTP Creates SQL Server database and file backups on schedule Compresses and encrypts the backups Sends backups to a network folder, FTP Server, Dropbox, Google Drive or Amazon S3 Sends email notifications of job’s success or failure SQLBackupAndFTP comes in Free and Paid versions (starting from $29) – see version comparison. Free version is fully functional for unlimited ad hoc backups or for scheduled backups of up to two databases – it will be sufficient for many small customers. What has impressed me from the beginning – is that I understood how it works and was able to configure the job from a single form (see Image 1 – Main form above) Connect to you SQL server and select databases to be backed up Click “Add backup destination” to configure where backups should go to (network, FTP Server, Dropbox, Google Drive or Amazon S3) Enter your email to receive email confirmations Set the time to start daily full backups (or go to Settings if you need Differential or  Transaction Log backups on a flexible schedule) Press “Run Now” button to test You can get to this form if you click “Settings” buttons in the “Schedule section”. Select what types of backups and how often you want to run them and you will see the scheduled backups in the “Estimated backup plan” list A detailed tutorial is available on the developer’s website. Along with SQLBackupAndFTP setup gives you the option to install “One-Click SQL Restore” (you can install it stand-alone too) – a basic tool for restoring just Full backups. However basic, you can drag-and-drop on it the zip file created by SQLBackupAndFTP, it unzips the BAK file if necessary, connects to the SQL server on the start, selects the right database, it is smart enough to restart the server to drop open connections if necessary – very handy for developers who need to restore databases often. You may ask why is this tool is better than maintenance tasks available in SQL Server? While maintenance tasks are easy to set up, SQLBackupAndFTP is still way easier and integrates solution for compression, encryption, FTP, cloud storage and email which make it superior to maintenance tasks in every aspect. On a flip side SQLBackupAndFTP is not the fanciest tool to manage backups or check their health. It only works reliably on local SQL Server instances. In other words it has to be installed on the SQL server itself. For remote servers it uses scripting which is less reliable. This limitations is actually inherent in SQL server itself as BACKUP DATABASE command  creates backup not on the client, but on the server itself. This tool is compatible with almost all the known SQL Server versions. It works with SQL Server 2008 (all versions) and many of the previous versions. It is especially useful for SQL Server Express 2005 and SQL Server Express 2008, as they lack built in tools for backup. I strongly recommend this tool to all the DBAs. They must absolutely try it as it is free and does exactly what it promises. You can download your free copy of the tool from here. Please share your experience about using this tool. I am eager to receive your feedback regarding this article. 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, SQL Utility, SQLServer, T SQL, Technology

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• SQL SERVER – CXPACKET – Parallelism – Advanced Solution – Wait Type – Day 7 of 28

  - by pinaldave

  Earlier we discussed about the what is the common solution to solve the issue with CXPACKET wait time. Today I am going to talk about few of the other suggestions which can help to reduce the CXPACKET wait. If you are going to suggest that I should focus on MAXDOP and COST THRESHOLD – I totally agree. I have covered them in details in yesterday’s blog post. Today we are going to discuss few other way CXPACKET can be reduced. Potential Reasons: If data is heavily skewed, there are chances that query optimizer may estimate the correct amount of the data leading to assign fewer thread to query. This can easily lead to uneven workload on threads and may create CXPAKCET wait. While retrieving the data one of the thread face IO, Memory or CPU bottleneck and have to wait to get those resources to execute its tasks, may create CXPACKET wait as well. Data which is retrieved is on different speed IO Subsystem. (This is not common and hardly possible but there are chances). Higher fragmentations in some area of the table can lead less data per page. This may lead to CXPACKET wait. As I said the reasons here mentioned are not the major cause of the CXPACKET wait but any kind of scenario can create the probable wait time. Best Practices to Reduce CXPACKET wait: Refer earlier article regarding MAXDOP and Cost Threshold. De-fragmentation of Index can help as more data can be obtained per page. (Assuming close to 100 fill-factor) If data is on multiple files which are on multiple similar speed physical drive, the CXPACKET wait may reduce. Keep the statistics updated, as this will give better estimate to query optimizer when assigning threads and dividing the data among available threads. Updating statistics can significantly improve the strength of the query optimizer to render proper execution plan. This may overall affect the parallelism process in positive way. Bad Practice: In one of the recent consultancy project, when I was called in I noticed that one of the ‘experienced’ DBA noticed higher CXPACKET wait and to reduce them, he has increased the worker threads. The reality was increasing worker thread has lead to many other issues. With more number of the threads, more amount of memory was used leading memory pressure. As there were more threads CPU scheduler faced higher ‘Context Switching’ leading further degrading performance. When I explained all these to ‘experienced’ DBA he suggested that now we should reduce the number of threads. Not really! Lower number of the threads may create heavy stalling for parallel queries. I suggest NOT to touch the setting of number of the threads when dealing with CXPACKET wait. Read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and I no way claim it to be accurate. I suggest reading book on-line for further clarification. All the discussion of Wait Stats over here is generic and it varies by system to system. You are recommended to test this on development server before implementing to production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, 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 – How to Compare the Schema of Two Databases with Schema Compare

  - by Pinal Dave

  Earlier I wrote about An Efficiency Tool to Compare and Synchronize SQL Server Databases and it was very much well received. Since the blog post I have received quite a many question that just like data how we can also compare schema and synchronize it. If you think about comparing the schema manually, it is almost impossible to do so. Table Schema has been just one of the concept but if you really want the all the schema of the database (triggers, views, stored procedure and everything else) it is just impossible task. If you are developer or database administrator who works in the production environment than you know that there are so many different occasions when we have to compare schema of the database. Before deploying any changes to the production server, I personally like to make note of the every single schema change and document it so in case of any issue , I can always go back and refer my documentation. As discussed earlier it is absolutely impossible to do this task without the help of third party tools. I personally use Devart Schema Compare for this task. This is an extremely easy tool. Let us see how it works. First I have two different databases – a) AdventureWorks2012 and b) AdventureWorks2012-V1. There are total three changes between these databases. Here is the list of the same. One of the table has additional column One of the table have new index One of the stored procedure is changed Now let see how dbForge Schema Compare works in this scenario. First open dbForge Schema Compare studio. Click on New Schema Comparison. It will bring you to following screen where we have to configure the database needed to configure. I have selected AdventureWorks2012 and AdventureWorks-V1 databases. In the next screen we can verify various options but for this demonstration we will keep it as it is. We will not change anything in schema mapping screen as in our case it is not required but generically if you are comparing across schema you may need this. This is the most important screen as on this screen we select which kind of object we want to compare. You can see the options which are available to select. The screen lets you select the objects from SQL Server 2000 to SQL Server 2012. Once you click on compare in previous screen it will bring you to this screen, which will essentially display the comparative difference between two of the databases which we had selected in earlier screen. As mentioned above there are three different changes in the database and the same has been listed over here. Two of the changes belongs to the tables and one changes belong to the procedure. Let us click each of them one by one to see what is the difference between them. In very first option we can see that there is an additional column in another database which did not exist earlier. In this example we can see that AdventureWorks2012 database have an additional index. Following example is very interesting as in this case, we have changed the definition of the stored procedure and the result pan contains the same. dbForget Schema Compare very effectively identify the changes in schema and lists them neatly to developers. Here is one more screen. This software not only compares the schema but also provides the options to update or drop them as per the choice. I think this is brilliant option. Well, I have been using schema compare for quite a while and have found it very useful. Here are few of the things which dbForge Schema Compare can do for developers and DBAs. Compare and synchronize SQL Server database schemas Compare schemas of live database and SQL Server backup Generate comparison reports in Excel and HTML formats Eliminate mistakes in schema changes propagation across environments Track production database changes and customizations Automate migration of schema changes using command line interface I suggest that you try out dbForge Schema Compare and let me know what you think of this product. 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 – #TechEdIn – Presenting Tomorrow on SQL Server Misconception and Resolution with Vinod Kumar at TechEd India 2012

  - by pinaldave

  I am excited AND nervous at the same time. I am going to present a very interesting topic tomorrow at an SQL Server track in India. This will be my fourth time presenting at TechEd India. So far, I have received so much feedback about this one session. It seems like every single person out there has their own wishes and requests. I am sure that it is going to very challenging experience to satisfy everyone who attends the event through my presentation. Surprise Element Here is the good news: I am going to co-present this session with Vinod Kumar, my long time friend and co-worker. We have known each other for almost four years now, but this is the very first time that we are going to present together on the big stage of TechEd.  When there are more than two presenters, the usual trick is to practice the session multiple times and know exactly what each other is going to present and talk about. However, there’s a catch – we decided to make it different this time and have shared nothing to each other regarding what exactly we are going to present. This makes everything extremely interesting as each of us will be as clueless as the audience when other person is going to talk. Action Item Here are a few of the action items for all of those who are going to attend this session. Vinod and I will be present at the venue 15 minutes before the session. Do come in early and talk with us. We would be glad to talk with you and see if either of us can accommodate your suggestion in our session. If we do, we will give a surprise gift for you. As discussed, this session is going to be a unique two-presenter session. You will have chance to take a side with one speaker and stump the other speaker. Come early to decide which speaker you want to cheer during the session. Quiz and Goodies By now, you must have figured out that this session is going to be an extremely interactive session. We need your support through your active participation. We will have some really brain-twisting quiz line up just for you. You will have to take part and win surprises from us! Trust me. If you get it right, we will give you something which can help you learn more! We will have a quiz on Twitter as well. We will ask a question in person and you will be able to participate on Twitter. 10 – Demos As I said, both of us do not know what each other is going to present, but there are few things which we know very well. We have 10 demos and 6 slides. I think this is going to be an exciting demo marathon. Trust me, you will love it and the taste of this session will be in your mouth till the next TechEd. Session Details Title: SQL Server Misconceptions and Resolution – A Practical Perspective (Add to Calendar) Abstract: “The earth is flat”! – An ancient common misconception, which has been proven incorrect as we progressed in modern times. In this session, we will see various database misconceptions prevailing and their resolutions with the aid of the demos. In this unique session, the audience will be a part of the conversation and resolution. Date and Time: March 21, 2012, 15:15 to 16:15 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 – Solution of Puzzle – Swap Value of Column Without Case Statement

  - by pinaldave

  Earlier this week I asked a question where I asked how to Swap Values of the column without using CASE Statement. Read here: SQL SERVER – A Puzzle – Swap Value of Column Without Case Statement. I have proposed 3 different solutions in the blog posts itself. I had requested the help of the community to come up with alternate solutions and honestly I am stunned and amazed by the qualified entries. I will be not able to cover every single solution which is posted as a comment, however, I would like to for sure cover few interesting entries. However, I am selecting 5 solutions which are different (not necessary they are most optimal or best – just different and interesting). Just for clarity I am involving the original problem statement here. USE tempdb GO CREATE TABLE SimpleTable (ID INT, Gender VARCHAR(10)) GO INSERT INTO SimpleTable (ID, Gender) SELECT 1, 'female' UNION ALL SELECT 2, 'male' UNION ALL SELECT 3, 'male' GO SELECT * FROM SimpleTable GO -- Insert Your Solutions here -- Swap value of Column Gender SELECT * FROM SimpleTable GO DROP TABLE SimpleTable GO Here are the five most interesting and different solutions I have received. Solution by Roji P Thomas UPDATE S SET S.Gender = D.Gender FROM SimpleTable S INNER JOIN SimpleTable D ON S.Gender != D.Gender I really loved the solutions as it is very simple and drives the point home – elegant and will work pretty much for any values (not necessarily restricted by the option in original question ‘male’ or ‘female’). Solution by Aneel CREATE TABLE #temp(id INT, datacolumn CHAR(4)) INSERT INTO #temp VALUES(1,'gent'),(2,'lady'),(3,'lady') DECLARE @value1 CHAR(4), @value2 CHAR(4) SET @value1 = 'lady' SET @value2 = 'gent' UPDATE #temp SET datacolumn = REPLACE(@value1 + @value2,datacolumn,'') Aneel has very interesting solution where he combined both the values and replace the original value. I personally liked this creativity of the solution. Solution by SIJIN KUMAR V P UPDATE SimpleTable SET Gender = RIGHT(('fe'+Gender), DIFFERENCE((Gender),SOUNDEX(Gender))*2) Sijin has amazed me with Difference and Soundex function. I have never visualized that above two functions can resolve the problem. Hats off to you Sijin. Solution by Nikhildas UPDATE St SET St.Gender = t.Gender FROM SimpleTable St CROSS Apply (SELECT DISTINCT gender FROM SimpleTable WHERE St.Gender != Gender) t I was expecting that someone will come up with this solution where they use CROSS APPLY. This is indeed very neat and for sure interesting exercise. If you do not know how CROSS APPLY works this is the time to learn. Solution by mistermagooo UPDATE SimpleTable SET Gender=X.NewGender FROM (VALUES('male','female'),('female','male')) AS X(OldGender,NewGender) WHERE SimpleTable.Gender=X.OldGender As per author this is a slow solution but I love how syntaxes are placed and used here. I love how he used syntax here. I will say this is the most beautifully written solution (not necessarily it is best). Bonus: Solution by Madhivanan Somehow I was confident Madhi – SQL Server MVP will come up with something which I will be compelled to read. He has written a complete blog post on this subject and I encourage all of you to go ahead and read it. Now personally I wanted to list every single comment here. There are some so good that I am just amazed with the creativity. I will write a part of this blog post in future. However, here is the challenge for you. Challenge: Go over 50+ various solutions listed to the simple problem here. Here are my two asks for you. 1) Pick your best solution and list here in the comment. This exercise will for sure teach us one or two things. 2) Write your own solution which is yet not covered already listed 50 solutions. I am confident that there is no end to creativity. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Function, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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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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