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• Big Data – Buzz Words: What is NewSQL – Day 10 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned the importance of the relational database. In this article we will take a quick look at the what is NewSQL. What is NewSQL? NewSQL stands for new scalable and high performance SQL Database vendors. The products sold by NewSQL vendors are horizontally scalable. NewSQL is not kind of databases but it is about vendors who supports emerging data products with relational database properties (like ACID, Transaction etc.) along with high performance. Products from NewSQL vendors usually follow in memory data for speedy access as well are available immediate scalability. NewSQL term was coined by 451 groups analyst Matthew Aslett in this particular blog post. On the definition of NewSQL, Aslett writes: “NewSQL” is our shorthand for the various new scalable/high performance SQL database vendors. We have previously referred to these products as ‘ScalableSQL‘ to differentiate them from the incumbent relational database products. Since this implies horizontal scalability, which is not necessarily a feature of all the products, we adopted the term ‘NewSQL’ in the new report. And to clarify, like NoSQL, NewSQL is not to be taken too literally: the new thing about the NewSQL vendors is the vendor, not the SQL. In other words - NewSQL incorporates the concepts and principles of Structured Query Language (SQL) and NoSQL languages. It combines reliability of SQL with the speed and performance of NoSQL. Categories of NewSQL There are three major categories of the NewSQL New Architecture – In this framework each node owns a subset of the data and queries are split into smaller query to sent to nodes to process the data. E.g. NuoDB, Clustrix, VoltDB MySQL Engines – Highly Optimized storage engine for SQL with the interface of MySQ Lare the example of such category. E.g. InnoDB, Akiban Transparent Sharding – This system automatically split database across multiple nodes. E.g. Scalearc  Summary In simple words – NewSQL is kind of database following relational database principals and provides scalability like NoSQL. Tomorrow In tomorrow’s blog post we will discuss about the Role of Cloud Computing in Big Data. 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

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• SQL – What ACID stands in the Database? – Contest to Win 24 Amazon Gift Cards and Joes 2 Pros 2012 Kit

  - by Pinal Dave

  We love puzzles. One of the brain’s main task is to solve puzzles. Sometime puzzles are very complicated (e.g Solving Rubik Cube or Sodoku)  and sometimes the puzzles are very simple (multiplying 4 by 8 or finding the shortest route while driving). It is always to solve puzzle and it creates an experience which humans are not able to forget easily. The best puzzles are the one where one has to do multiple things to reach to the final goal. Let us do something similar today. We will have a contest where you can participate and win something interesting. Contest This contest have two parts. Question 1: What ACID stands in the Database? This question seems very easy but here is the twist. Your answer should explain minimum one of the properties of the ACID in detail. If you wish you can explain all the four properties of the ACID but to qualify you need to explain minimum of the one properties. Question 2: What is the size of the installation file of NuoDB for any specific platform. You can answer this question following format – NuoDB installation file is of size __ MB for ___ Platform. Click on the Download the Link and download your installation file for NuoDB. You can post figure out the file size from the properties of the file. We have exciting content prizes for the winners. Prizes 1) 24 Amazon Gift Cards of USD 10 for next 24 hours. One card at every hour. (Open anywhere in the world) 2) One grand winner will get Joes 2 Pros SQL Server 2012 Training Kit worth USD 249. (Open where Amazon ship books). Amazon | 1 | 2 | 3 | 4 | 5  Rules The contest will be open till July 21, 2013. All the valid comments will be hidden till the result is announced. The winners will be announced on July 24, 2013. Hint: Download NuoDB  Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Template Browser – A Very Important and Useful Feature of SSMS

  - by pinaldave

  Let me start today’s blog post with a direction question. How many of you have ever used Template Browser? Template Browser is a very important and useful feature of SQL Server Management Studio (SSMS). Every time when I am talking about SQL Server there is always someone comes up with the question, why there is no step by step procedure included in SSMS for features. Honestly every time I get this question, the question I ask back is How many of you have ever used Template Browser? I think the answer to this question is most of the time either no or we have not heard of the feature. One of the people asked me back – have you ever written about it on your blog? I have not yet written about it. Basically there is nothing much to write about it. It is pretty straight forward feature, like any other feature and it is indeed difficult to elaborate. However, I will try to give a quick introduction to this feature. Templates are like a quick cheat sheet or quick reference. Templates are available to create objects like databases, tables, views, indexes, stored procedures, triggers, statistics, and functions. Templates are also available for Analysis Services as well. The template scripts contain parameters to help you customize the code. You can Replace Template Parameters dialog box to insert values into the script. Additionally users can create new custom templates as well with folder structure. To open a template from Template Explorer Go to View menu >> Template Explorer or type CTRL+ALT+L. You will find a list of categories click on any category and expand the folder structure. For our sample example let us expand Index Folder. In this folder you will notice the various T-SQL Scripts. These scripts can be opened by double click or can be dragged to editor area and modified as needed. Sample template is now available in the query editor area with all the necessary parameter place folder. You can replace the same parameter by typing either CTRL+SHIFT+M or by going to Query Menu >> Specify Values for Template Parameters. In this screen it will show  Specify Values for Template Parameters dialog box, accept the value or replace it with a new value. This will now get your script ready to go. Check it one more time and change the script to fit your requirement. I personally use template explorer for two things. First one is obviously for templates but the hidden one and an important one is for learning new features and T-SQL commands. There is so much to learn and so little time. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology

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• SQLAuthority News – Download Whitepaper – SQL Server Analysis Services to Hive

  - by pinaldave

  The SQL Server Analysis Service is a very interesting subject and I always have enjoyed learning about it. You can read my earlier article over here. Big Data is my new interest and I have been exploring it recently. During this weekend this blog post caught my attention and I enjoyed reading it. Big Data is the next big thing. The growth is predicted to be 60% per year till 2016. There is no single solution to the growing need of the big data available in the market right now as well there is no one solution in the business intelligence eco-system available as well. However, the need of the solution is ever increasing. I am personally Klout user. You can see my Klout profile over. I do understand what Klout is trying to achieve – a single place to measure the influence of the person. However, it works a bit mysteriously. There are plenty of social media available currently in the internet world. The biggest problem all the social media faces is that everybody opens an account but hardly people logs back in. To overcome this issue and have returned visitors Klout has come up with the system where visitors can give 5/10 K+ to other users in a particular area. Looking at all the activities Klout is doing it is indeed big consumer of the Big Data as well it is early adopter of the big data and Hadoop based system.  Klout has to 1 trillion rows of data to be analyzed as well have nearly thousand terabyte warehouse. Hive the language used for Big Data supports Ad-Hoc Queries using HiveQL there are always better solutions. The alternate solution would be using SQL Server Analysis Services (SSAS) along with HiveQL. As there is no direct method to achieve there are few common workarounds already in place. A new ODBC driver from Klout has broken through the limitation and SQL Server Relation Engine can be used as an intermediate stage before SSAS. In this white paper the same solutions have been discussed in the depth. The white paper discusses following important concepts. The Klout Big Data solution Big Data Analytics based on Analysis Services Hadoop/Hive and Analysis Services integration Limitations of direct connectivity Pass-through queries to linked servers Best practices and lessons learned This white paper discussed all the important concepts which have enabled Klout to go go to the next level with all the offerings as well helped efficiency by offering a few out of the box solutions. I personally enjoy reading this white paper and I encourage all of you to do so. SQL Server Analysis Services to Hive Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL White Papers, T SQL, Technology

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• SQL SERVER – SSAS – Multidimensional Space Terms and Explanation

  - by pinaldave

  I was presenting on SQL Server session at one of the Tech Ed On Road event in India. I was asked very interesting question during ‘Stump the Speaker‘ session. I am sharing the same with all of you over here. Question: Can you tell me in simple words what is dimension, member and other terms of multidimensional space? There is no simple example for it. This is extreme fundamental question if you know Analysis Service. Those who have no exposure to the same and have not yet started on this subject, may find it a bit difficult. I really liked his question so I decided to answer him there as well blog about the same over here. Answer: Here are the most important terms of multidimensional space – dimension, member, value, attribute and size. Dimension – It describes the point of interests for analysis. Member – It is one of the point of interests in the dimension. Value – It uniquely describes the member. Attribute – It is collection of multiple members. Size – It is total numbers for any dimension. Let us understand this further detail taking example of any space. I am going to take example of distance as a space in our example. Dimension – Distance is a dimension for us. Member – Kilometer – We can measure distance in Kilometer. Value – 4 – We can measure distance in the kilometer unit and the value of the unit can be 4. Attribute – Kilometer, Miles, Meter – The complete set of members is called attribute. Size – 100 KM – The maximum size decided for the dimension is called size. The same example can be also defined by using time space. Here is the example using time space. Dimension – Time Member – Date Value – 25 Attribute – 1, 2, 3…31 Size – 31 I hope it is clear enough that what are various multidimensional space and its terms. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Business Intelligence, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL – Biggest Concerns in a Data-Driven World

  - by Pinal Dave

  The ongoing chaos over Government Agency’s snooping has ignited a heated debate on privacy of personal data and its use by government and/or other institutions. It has created a feeling of disapproval and distrust among users. This incident proves to be a lesson for companies that are looking to leverage their business using a data driven approach. According to analysts, the goal of gathering personal information should be to deliver benefits to both the parties – the user as well as the data collector(government or business). Using data the right way is crucial, and companies need to deploy the right software applications and systems to ensure that their efforts are well-directed. However, there are various issues plaguing analysts regarding available software, which are highlighted below. According to a InformationWeek 2013 Survey of Analytics, Business Intelligence and Information Management where 541 business technology professionals contributed as respondents, it was discovered that the biggest concern was deemed to be the scarcity of expertise and high costs associated with the same. This concern was voiced by as many as 38% of the participants. A close second came out to be the issue of data warehouse appliance platforms being expensive, with 33% of those present believing it to be a huge roadblock. Another revelation made in this respect was that 31% professionals weren’t even sure how Data Analytics can create business opportunities for them. Another 17% shared that they found data platform technologies such as Hadoop and NoSQL technologies hard to learn. These results clearly pointed out that there are awareness and expertise issues that also need much attention. Unless the demand-supply gap of Business Intelligence professionals well versed in data analysis technologies is met, this divide is going to affect how companies make the most of their BI campaigns. One of the key action points that can be taken to salvage the situation, is to provide training on Data Analytics concepts. Koenig Solutions offer courses on many such technologies including a course on MCSE SQL Server 2012: BI Platform. So it’s time to brush up your skills and get down to work in a data driven world that awaits you ahead. 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

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• SQL SERVER – DELETE, TRUNCATE and RESEED Identity

  - by pinaldave

  Yesterday I had a headache answering questions to one of the DBA on the subject of Reseting Identity Values for All Tables. After talking to the DBA I realized that he has no clue about how the identity column behaves when there is DELETE, TRUNCATE or RESEED Identity is used. Let us run a small T-SQL Script. Create a temp table with Identity column beginning with value 11. The seed value is 11. USE [TempDB] GO -- Create Table CREATE TABLE [dbo].[TestTable]( [ID] [int] IDENTITY(11,1) NOT NULL, [var] [nchar](10) NULL ) ON [PRIMARY] GO -- Build sample data INSERT INTO [TestTable] VALUES ('val') GO When seed value is 11 the next value which is inserted has the identity column value as 11. – Select Data SELECT * FROM [TestTable] GO Effect of DELETE statement -- Delete Data DELETE FROM [TestTable] GO When the DELETE statement is executed without WHERE clause it will delete all the rows. However, when a new record is inserted the identity value is increased from 11 to 12. It does not reset but keep on increasing. -- Build sample data INSERT INTO [TestTable] VALUES ('val') GO -- Select Data SELECT * FROM [TestTable] Effect of TRUNCATE statement -- Truncate table TRUNCATE TABLE [TestTable] GO When the TRUNCATE statement is executed it will remove all the rows. However, when a new record is inserted the identity value is increased from 11 (which is original value). TRUNCATE resets the identity value to the original seed value of the table. -- Build sample data INSERT INTO [TestTable] VALUES ('val') GO -- Select Data SELECT * FROM [TestTable] GO Effect of RESEED statement If you notice I am using the reseed value as 1. The original seed value when I created table is 11. However, I am reseeding it with value 1. -- Reseed DBCC CHECKIDENT ('TestTable', RESEED, 1) GO When we insert the one more value and check the value it will generate the new value as 2. This new value logic is Reseed Value + Interval Value – in this case it will be 1+1 = 2. -- Build sample data INSERT INTO [TestTable] VALUES ('val') GO -- Select Data SELECT * FROM [TestTable] GO Here is the clean up act. -- Clean up DROP TABLE [TestTable] GO Question for you: If I reseed value with some random number followed by the truncate command on the table what will be the seed value of the table. (Example, if original seed value is 11 and I reseed the value to 1. If I follow up with truncate table what will be the seed value now? Here is the complete script together. You can modify it and find the answer to the above question. Please leave a comment with your answer. 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 – QUOTED_IDENTIFIER ON/OFF Explanation and Example – Question on Real World Usage

  - by Pinal Dave

  This is a follow up blog post of SQL SERVER – QUOTED_IDENTIFIER ON/OFF and ANSI_NULL ON/OFF Explanation. I wrote that blog six years ago and I had plans that I will write a follow up blog post of the same. Today, when I was going over my to-do list and I was surprised that I had an item there which was six years old and I never got to do that. In the earlier blog post I wrote about exploitation of the Quoted Identifier and ANSI Null. In this blog post we will see a quick example of Quoted Identifier. However, before we continue this blog post, let us see a refresh what both of Quoted Identifider do. QUOTED IDENTIFIER ON/OFF This option specifies the setting for use of double quotes. When this is on, double quotation mark is used as part of the SQL Server identifier (object name). This can be useful in situations in which identifiers are also SQL Server reserved words. In simple words when we have QUOTED IDENTIFIER ON, anything which is wrapped in double quotes becomes an object. E.g. -- The following will work SET QUOTED_IDENTIFIER ON GO CREATE DATABASE "Test1" GO -- The following will throw an error about Incorrect syntax near 'Test2'. SET QUOTED_IDENTIFIER OFF GO CREATE DATABASE "Test2" GO This feature is particularly helpful when we are working with reserved keywords in SQL Server. For example if you have to create a database with the name VARCHAR or INT or DATABASE you may want to put double quotes around your database name and turn on quoted identifiers to create a database with the such name. Personally, I do not think so anybody will ever create a database with the reserve keywords intentionally, as it will just lead to confusion. Here is another example to give you further clarity about how Quoted Idenifier setting works with SELECT statement. -- The following will throw an error about Invalid column name 'Column'. SET QUOTED_IDENTIFIER ON GO SELECT "Column" GO -- The following will work SET QUOTED_IDENTIFIER OFF GO SELECT "Column" GO Personally, I always use the following method to create database as it works irrespective of what is the quoted identifier’s status. It always creates objects with my desire name whenever I would like to create. CREATE DATABASE [Test3] I believe the future of the quoted identifier on or off is useful in the real world when we have script generated from another database where this setting was ON and we have to now execute the same script again in our environment again. Question to you - I personally have never used this feature as I mentioned earlier. I believe this feature is there to support the scripts which are generated in another SQL Database or generate the script for other database. Do you have a real world scenario where we need to turn on or off Quoted Identifiers. Click to Download Scripts 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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• Developer – Cross-Platform: Fact or Fiction?

  - by Pinal Dave

  This is a guest blog post by Jeff McVeigh. Jeff McVeigh is the general manager of Performance Client and Visual Computing within Intel’s Developer Products Division. His team is responsible for the development and delivery of leading software products for performance-centric application developers spanning Android*, Windows*, and OS* X operating systems. During his 17-year career at Intel, Jeff has held various technical and management positions in the fields of media, graphics, and validation. He also served as the technical assistant to Intel’s CTO. He holds 20 patents and a Ph.D. in electrical and computer engineering from Carnegie Mellon University. It’s not a homogenous world. We all know it. I have a Windows* desktop, a MacBook Air*, an Android phone, and my kids are 100% Apple. We used to have 2.5 kids, now we have 2.5 devices. And we all agree that diversity is great, unless you’re a developer trying to prioritize the limited hours in the day. Then it’s a series of trade-offs. Do we become brand loyalists for Google or Apple or Microsoft? Do we specialize on phones and tablets or still consider the 300M+ PC shipments a year when we make our decisions on where to spend our time and resources? We weigh the platform options, monetization opportunities, APIs, and distribution models. Too often, I see developers choose one platform, or write to the lowest common denominator, which limits their reach and market success. But who wants to be ?me too”? Cross-platform coding is possible in some environments, for some applications, for some level of innovation—but it’s not all-inclusive, yet. There are some tricks of the trade to develop cross-platform, including using languages and environments that ?run everywhere.” HTML5 is today’s answer for web-enabled platforms. However, it’s not a panacea, especially if your app requires the ultimate performance or native UI look and feel. There are other cross-platform frameworks that address the presentation layer of your application. But for those apps that have a preponderance of native code (e.g., highly-tuned C/C++ loops), there aren’t tons of solutions today to help with code reuse across these platforms using consistent tools and libraries. As we move forward with interim solutions, they’ll improve and become more robust, based, in no small part, on our input. What’s your answer to the cross-platform challenge? Are you fully invested in HTML5 now? What are your barriers? What’s your vision to navigate the cross-platform landscape?  Here is the link where you can head next and learn more about how to answer the questions I have asked: https://software.intel.com/en-us Republished with permission from here. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Intel

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• SQL SERVER – Backup SQL databases to Box or SkyDrive

  - by Pinal Dave

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

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• SQL SERVER – ERROR: FIX using Compatibility Level – Database diagram support objects cannot be installed because this database does not have a valid owner – Part 2

  - by pinaldave

  Earlier I wrote a blog post about how to resolve the error with database diagram. Today I faced the same error when I was dealing with a database which is upgraded from SQL Server 2005 to SQL Server 2008 R2. When I was searching for the solution online I ended up on my own earlier solution SQL SERVER – ERROR: FIX – Database diagram support objects cannot be installed because this database does not have a valid owner. I really found it interesting that I ended up on my own solution. However, the solution to the problem this time was a bit different. Let us see how we can resolve the same. Error: Database diagram support objects cannot be installed because this database does not have a valid owner. To continue, first use the Files page of the Database Properties dialog box or the ALTER AUTHORIZATION statement to set the database owner to a valid login, then add the database diagram support objects. Workaround / Fix / Solution : Follow the steps listed below and it should for sure solve your problem. (NOTE: Please try this for the databases upgraded from previous version. For everybody else you should just follow the steps mentioned here.) Select your database >> Right Click >> Select Properties Go to the Options In the Dropdown at right labeled “Compatibility Level” choose “SQL Server 2005(90)” Select FILE in left side of page In the OWNER box, select button which has three dots (…) in it Now select user ‘sa’ or NT AUTHORITY\SYSTEM and click OK. This will solve your problem. However, there is one very important note you must consider. When you change any database owner, there are always security related implications. I suggest you check your security policies before changing authorization. I did this to quickly solve my problem on my development server. If you are on production server, you may open yourself to potential security compromise. 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

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• SQL SERVER – Fix: Error: 147 An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference

  - by pinaldave

  Everybody was beginner once and I always like to get involved in the questions from beginners. There is a big difference between the question from beginner and question from advanced user. I have noticed that if an advanced user gets an error, they usually need just a small hint to resolve the problem. However, when a beginner gets error he sometimes sits on the error for a long time as he/she has no idea about how to solve the problem as well have no idea regarding what is the capability of the product. I recently received a very novice level question. When I received the problem I quickly see how the user was stuck. When I replied him with the solution, he wrote a long email explaining how he was not able to solve the problem. He thanked multiple times in the email. This whole thing inspired me to write this quick blog post. I have modified the user’s question to match the code with AdventureWorks as well simplified so it contains the core content which I wanted to discuss. Problem Statement: Find all the details of SalesOrderHeaders for the latest ShipDate. He comes up with following T-SQL Query: SELECT * FROM [Sales].[SalesOrderHeader] WHERE ShipDate = MAX(ShipDate) GO When he executed above script it gave him following error: Msg 147, Level 15, State 1, Line 3 An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference. He was not able to resolve this problem, even though the solution was given in the query description itself. Due to lack of experience he came up with another version of above query based on the error message. SELECT * FROM [Sales].[SalesOrderHeader] HAVING ShipDate = MAX(ShipDate) GO When he ran above query it produced another error. Msg 8121, Level 16, State 1, Line 3 Column ‘Sales.SalesOrderHeader.ShipDate’ is invalid in the HAVING clause because it is not contained in either an aggregate function or the GROUP BY clause. What he wanted actually was the SalesOrderHeader all the Sales shipped on the last day. Based on the problem statement what the right solution is as following, which does not generate error. SELECT * FROM [Sales].[SalesOrderHeader] WHERE ShipDate = (SELECT MAX(ShipDate) FROM [Sales].[SalesOrderHeader]) Well, that’s it! Very simple. With SQL Server there are always multiple solution to a single problem. Is there any other solution available to the problem stated? Please share in the comment. 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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• MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

  - by Pinal Dave

  MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which can teach them MySQL from the beginning. Here is the good news, I have written two different courses on MySQL Fundamentals, which is available online. The reason for writing two different courses was to keep the learning simple. Both of the courses are absolutely connected with other but designed if you watch either of the course independently you can watch them and learn without dependencies. However, if you ask me, I will suggest that you watch MySQL Fundamentals Part 1 course following with MySQL Fundamentals Part 2 course. Let us quickly explore outline of MySQL courses. MySQL Fundamental – 1 (157 minutes) MySQL is a popular choice of database for use in web applications, and is a central component of the widely used LAMP open source web application software stack. This course covers the fundamentals of MySQL, including how to install MySQL as well as written basic data retrieval and data modification queries. Introduction (duration 00:02:12) Installations and GUI Tools (duration 00:13:51) Fundamentals of RDBMS and Database Designs (duration 00:16:13) Introduction MYSQL Workbench (duration 00:31:51) Data Retrieval Techniques (duration 01:11:13) Data Modification Techniques (duration 00:20:41) Summary and Resources (duration 00:01:31) MySQL Fundamental – 2 (163 minutes) MySQL is a popular choice of database for use in web applications, and is a central component of the widely used LAMP open source web application software stack. In this course, which is part 2 of the Fundamentals of MySQL series, we explore more advanced topics such as stored procedures & user-defined functions, subqueries & joins, views and events & triggers. Introduction (duration 00:02:09) Joins, Unions and Subqueries (duration 01:03:56) MySQL Functions (duration 00:36:55) MySQL Views (duration 00:19:19) Stored Procedures and Stored Functions (duration 00:25:23) Triggers and Events (duration 00:13:41) Summary and Resources (duration 00:02:18) Note if you click on the link above and you do not see the play button to watch the course, you will have to login to the system and watch the course. I would like to throw a challenge to you – Can you watch both of the courses in a single day? If yes, once you are done watching the course on your Pluralsight Profile Page (here is my profile http://pluralsight.com/training/users/pinal-dave) you will get following badges. If you have already watched MySQL Fundamental Part 1, you can qualify by just watching MySQL Fundamental Part 2. Just send me the link to your profile and I will publish your name on this blog. For the first five people who send me email at Pinal at sqlauthority.com; I might have something cool as a giveaway as well. Watch the teaser of MySQL course. Reference: Pinal Dave (http://blog.sqlauthority.com)  Filed under: MySQL, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Introduction to Wait Stats and Wait Types – Wait Type – Day 1 of 28

  - by pinaldave

  I have been working a lot on Wait Stats and Wait Types recently. Last Year, I requested blog readers to send me their respective server’s wait stats. I appreciate their kind response as I have received  Wait stats from my readers. I took each of the results and carefully analyzed them. I provided necessary feedback to the person who sent me his wait stats and wait types. Based on the feedbacks I got, many of the readers have tuned their server. After a while I got further feedbacks on my recommendations and again, I collected wait stats. I recorded the wait stats and my recommendations and did further research. At some point at time, there were more than 10 different round trips of the recommendations and suggestions. Finally, after six month of working my hands on performance tuning, I have collected some real world wisdom because of this. Now I plan to share my findings with all of you over here. Before anything else, please note that all of these are based on my personal observations and opinions. They may or may not match the theory available at other places. Some of the suggestions may not match your situation. Remember, every server is different and consequently, there is more than one solution to a particular problem. However, this series is written with kept wait stats in mind. While I was working on various performance tuning consultations, I did many more things than just tuning wait stats. Today we will discuss how to capture the wait stats. I use the script diagnostic script created by my friend and SQL Server Expert Glenn Berry to collect wait stats. Here is the script to collect the wait stats: -- Isolate top waits for server instance since last restart or statistics clear WITH Waits AS (SELECT wait_type, wait_time_ms / 1000. AS wait_time_s, 100. * wait_time_ms / SUM(wait_time_ms) OVER() AS pct, ROW_NUMBER() OVER(ORDER BY wait_time_ms DESC) AS rn FROM sys.dm_os_wait_stats WHERE wait_type NOT IN ('CLR_SEMAPHORE','LAZYWRITER_SLEEP','RESOURCE_QUEUE','SLEEP_TASK' ,'SLEEP_SYSTEMTASK','SQLTRACE_BUFFER_FLUSH','WAITFOR', 'LOGMGR_QUEUE','CHECKPOINT_QUEUE' ,'REQUEST_FOR_DEADLOCK_SEARCH','XE_TIMER_EVENT','BROKER_TO_FLUSH','BROKER_TASK_STOP','CLR_MANUAL_EVENT' ,'CLR_AUTO_EVENT','DISPATCHER_QUEUE_SEMAPHORE', 'FT_IFTS_SCHEDULER_IDLE_WAIT' ,'XE_DISPATCHER_WAIT', 'XE_DISPATCHER_JOIN', 'SQLTRACE_INCREMENTAL_FLUSH_SLEEP')) SELECT W1.wait_type, CAST(W1.wait_time_s AS DECIMAL(12, 2)) AS wait_time_s, CAST(W1.pct AS DECIMAL(12, 2)) AS pct, CAST(SUM(W2.pct) AS DECIMAL(12, 2)) AS running_pct FROM Waits AS W1 INNER JOIN Waits AS W2 ON W2.rn <= W1.rn GROUP BY W1.rn, W1.wait_type, W1.wait_time_s, W1.pct HAVING SUM(W2.pct) - W1.pct < 99 OPTION (RECOMPILE); -- percentage threshold GO This script uses Dynamic Management View sys.dm_os_wait_stats to collect the wait stats. It omits the system-related wait stats which are not useful to diagnose performance-related bottleneck. Additionally, not OPTION (RECOMPILE) at the end of the DMV will ensure that every time the query runs, it retrieves new data and not the cached data. This dynamic management view collects all the information since the time when the SQL Server services have been restarted. You can also manually clear the wait stats using the following command: DBCC SQLPERF('sys.dm_os_wait_stats', CLEAR); Once the wait stats are collected, we can start analysis them and try to see what is causing any particular wait stats to achieve higher percentages than the others. Many waits stats are related to one another. When the CPU pressure is high, all the CPU-related wait stats show up on top. But when that is fixed, all the wait stats related to the CPU start showing reasonable percentages. It is difficult to have a sure solution, but there are good indications and good suggestions on how to solve this. I will keep this blog post updated as I will post more details about wait stats and how I reduce them. The reference to Book On Line is over here. Of course, I have selected February to run this Wait Stats series. I am already cheating by having the smallest month to run this series. :) Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, PostADay, SQL, SQL Authority, SQL Optimization, SQL Performance, 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 – Video – Beginning Performance Tuning with SQL Server Execution Plan

  - by pinaldave

  Traveling can be most interesting or most exhausting experience. However, traveling is always the most enlightening experience one can have. While going to long journey one has to prepare a lot of things. Pack necessary travel gears, clothes and medicines. However, the most essential part of travel is the journey to the destination. There are many variations one prefer but the ultimate goal is to have a delightful experience during the journey. Here is the video available which explains how to begin with SQL Server Execution plans. Performance Tuning is a Journey Performance tuning is just like a long journey. The goal of performance tuning is efficient and least resources consuming query execution with accurate results. Just as maps are the most essential aspect of performance tuning the same way, execution plans are essentially maps for SQL Server to reach to the resultset. The goal of the execution plan is to find the most efficient path which translates the least usage of the resources (CPU, memory, IO etc). Execution Plans are like Maps When online maps were invented (e.g. Bing, Google, Mapquests etc) initially it was not possible to customize them. They were given a single route to reach to the destination. As time evolved now it is possible to give various hints to the maps, for example ‘via public transport’, ‘walking’, ‘fastest route’, ‘shortest route’, ‘avoid highway’. There are places where we manually drag the route and make it appropriate to our needs. The same situation is with SQL Server Execution Plans, if we want to tune the queries, we need to understand the execution plans and execution plans internals. We need to understand the smallest details which relate to execution plan when we our destination is optimal queries. Understanding Execution Plans The biggest challenge with maps are figuring out the optimal path. The same way the  most common challenge with execution plans is where to start from and which precise route to take. Here is a quick list of the frequently asked questions related to execution plans: Should I read the execution plans from bottoms up or top down? Is execution plans are left to right or right to left? What is the relational between actual execution plan and estimated execution plan? When I mouse over operator I see CPU and IO but not memory, why? Sometime I ran the query multiple times and I get different execution plan, why? How to cache the query execution plan and data? I created an optimal index but the query is not using it. What should I change – query, index or provide hints? What are the tools available which helps quickly to debug performance problems? Etc… Honestly the list is quite a big and humanly impossible to write everything in the words. SQL Server Performance:  Introduction to Query Tuning My friend Vinod Kumar and I have created for the same a video learning course for beginning performance tuning. We have covered plethora of the subject in the course. Here is the quick list of the same: Execution Plan Basics Essential Indexing Techniques Query Design for Performance Performance Tuning Tools Tips and Tricks Checklist: Performance Tuning We believe we have covered a lot in this four hour course and we encourage you to go over the video course if you are interested in Beginning SQL Server Performance Tuning and Query Tuning. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology, Video Tagged: Execution Plan

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• SQLAuthority News – 1600 Blog Post Articles – A Milestone

  - by pinaldave

  It was really a very interesting moment for me when I was writing my 1600th milestone blog post. Now it`s a lot more exciting because this time it`s my 1600th blog post. Every time I write a milestone blog post such as this, I have the same excitement as when I was writing my very first blog post. Today I want to write about a few statistics of the blog. Statistics I am frequently asked about my blog stats, so I have already published my blog stats which are measured by WordPress.com. Currently, I have more than 22 Million+ Views on this blog from various sources. There are more than 6200+ feed subscribers in Google Reader only; I think I don`t have to count all other subscribers. My LinkedIn has 1250+ connection, while my Twitter has 2150+. Because I feel that I`m well connected with the Community, I am very thankful to you, my readers. Today I also want to say Thank You to those experts who have helped me to improve. I have maintained a list of all the articles I have written. If you go to my first articles, you will notice that they were a little different from the articles I am writing today. The reason for this is simple: I have two kinds of people helping me write all the better: readers and experts. To my Readers You read the articles and gave me feedback about what was right or wrong, what you liked or disliked. Quite often, you were helpful in writing guest posts, and I also recognize how you were a bit brutal in criticizing some articles, making me re-write them. Because of you, I was able to write better blog posts. To Experts You read the articles and helped me improve. I get inspiration from you and learned a lot from you. Just like everybody, I am a guy who is trying to learn. There are times when I had vague understanding of some subjects, and you did not hesitate to help me. Number of Posts Many ask me if the number of posts is important to me. My answer is YES. Actually, it`s just not about the number of my posts; it is about my blog, my routine, my learning experience and my journey. During the last four years, I have decided that I would be learning one thing a day. This blog has helped me accomplish this goal because in here I have been able to keep my notes and bookmarks. Whatever I learn or experience, I blog and share it with the Community. For me, the blog post number is more than just a number: it`s a summary of my experiences and memories. Once again, thanks for reading and supporting my blog! Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Pinal Dave, PostADay, SQL, SQL Authority, SQL Milestone, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, SQLServer, T SQL, Technology

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• Developer’s Life – Every Developer is a Batman

  - by Pinal Dave

  Batman is one of the darkest superheroes in the fantasy canon.  He does not come to his powers through any sort of magical coincidence or radioactive insect, but through a lot of psychological scarring caused by witnessing the death of his parents.  Despite his dark back story, he possesses a lot of admirable abilities that I feel bear comparison to developers. Batman has the distinct advantage that his alter ego, Bruce Wayne is a millionaire (or billionaire in today’s reboots).  This means that he can spend his time working on his athletic abilities, building a secret lair, and investing his money in cool tools.  This might not be true for developers (well, most developers), but I still think there are many parallels. So how are developers like Batman? Well, read on my list of reasons. Develop Skills Batman works on his skills.  He didn’t get the strength to scale Gotham’s skyscrapers by inheriting his powers or suffering an industrial accident.  Developers also hone their skills daily.  They might not be doing pull-ups and scaling buldings, but I think their skills are just as impressive. Clear Goals Batman is driven to build a better Gotham.  He knows that the criminal who killed his parents was a small-time thief, not a super villain – so he has larger goals in mind than simply chasing one villain.  He wants his city as a whole to be better.  Developers are also driven to make things better.  It can be easy to get hung up on one problem, but in the end it is best to focus on the well-being of the system as a whole. Ultimate Teamplayers Batman is the hero Gotham needs – even when that means appearing to be the bad guys.  Developers probably know that feeling well.  Batman takes the fall for a crime he didn’t commit, and developers often have to deliver bad news about the limitations of their networks and servers.  It’s not always a job filled with glory and thanks, but someone has to do it. Always Ready Batman and the Boy Scouts have this in common – they are always prepared.  Let’s add developers to this list.  Batman has an amazing tool belt with gadgets and gizmos, and let’s not even get into all the functions of the Batmobile!  Developers’ skills might be the knowledge and skills they have developed, not tools they can carry in a utility belt, but that doesn’t make them any less impressive. 100% Dedication Bruce Wayne cultivates the personality of a playboy, never keeping the same girlfriend for long and spending his time partying.  Even though he hides it, his driving force is his deep concern and love for his friends and the city as a whole.  Developers also care a lot about their company and employees – even when it is driving them crazy.  You do your best work when you care about your job on a personal level. Quality Output Batman believes the city deserves to be saved.  The citizens might have a love-hate relationship with both Batman and Bruce Wayne, and employees might not always appreciate developers.  Batman and developers, though, keep working for the best of everyone. I hope you are all enjoying reading about developers-as-superheroes as much as I am enjoying writing about them.  Please tell me how else developers are like Superheroes in the comments – especially if you know any developers who are faster than a speeding bullet and can leap tall buildings in a single bound. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Developer, Superhero

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• Developer’s Life – Every Developer is a Superman

  - by Pinal Dave

  I enjoyed comparing developers to Spiderman so much, that I have decided to continue the trend and encourage some of my favorite people (developers) with another favorite superhero – Superman.  Superman is probably the most famous superhero – and one of the most inspiring. Everyone has their own favorite, but Superman has been the longest enduring of all comic book characters.  Clark Kent has inspired multiple movie series, TV shows, books, cartoons, and costumes.  Superman’s enduring popularity has been attributed to his superhuman strength, integrity, dedication to good, and his humility in keeping his identity a secret. So how are developers like Superman? Well, read on my list of reasons. Secret Identities They have secret identities.  I’m not saying that all developers wear thick glasses and go by an alias like “Clark Kent.”  But developers certainly work in the background, making sure everything runs smoothly, often without recognition.  Like Superman, when they have done their job right, no one knows they were there. Working Alone You don’t have to work alone.  Superman doesn’t have a sidekick like Robin or Bat Girl, but he is a major player in the Justice League.  Developers have amazing skills, and they shouldn’t be afraid to unite those skills to solve some of the world’s major problems (like slow networks). Daily Inspiration Developers are inspiring.  Clark Kent works at The Daily Planet, Metropolis’ newspaper, which is lucky because he can keep some of the publicity Superman inspires under wraps.  Developers might go unnoticed sometimes, but when people hear about some of the tasks they accomplish on a daily basis, it inspires awe. Discover Your Superpowers You have to discover your superpowers.  Clark Kent didn’t just wake up one morning with the full understanding that he could fly, leap tall buildings in a single bound, and was stronger than a speeding locomotive.  He slowly discovered these powers (after a few comic book-worthy misunderstandings!).  Developers are always learning and growing as well.  You probably won’t wake up with super powers, either, but years of practice and continuing education can get you close. Every Day is a New Day The story continues.  The Superman comic books are still being printed, and have been in print since 1938.  There have been two TV series, (one, Smallville, was on TV for ten seasons) and multiple cartoon adaptations.  There have been multiple movies, with many different actors.  A new reboot came out last year, and another is set to premier in 2016.   So, developers, when you are having a bad day or a problem seems unsolvable – remember, the story will continue!  There is always tomorrow. I hope you are all enjoying reading about developers-as-superheroes as much as I am enjoying writing about them.  Please tell me how else developers are like Superheroes in the comments – especially if you know any developers who are faster than a speeding bullet and can leap tall buildings in a single bound. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Developer, Superhero

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• Developer Training – Importance and Significance – Part 1

  - by pinaldave

  Developer Training - Importance and Significance - Part 1 Developer Training – Employee Morals and Ethics – Part 2 Developer Training – Difficult Questions and Alternative Perspective - Part 3 Developer Training – Various Options for Developer Training – Part 4 Developer Training – A Conclusive Summary- Part 5 Can anyone remember their final day of schooling?  This is probably a silly question because – of course you can!  Many people mark this as the most exciting, happiest day of their life.  It marks the end of testing, the end of following rules set by teachers, and the beginning of finally being able to earn money and work in your chosen field. Beginning in Real World However, many former-students will be disappointed to find out that once they become employees, learning is not over.  Many companies are discovering the importance and benefits to training their employees.  You can breathe a sigh of relief, though, because much for this kind of training there are not usually tests! We often think that we go to school for our younger years so that we do all our learning all at once, and then for the rest of our lives we use that knowledge.  But in so many cases, but especially for developers, the opposite is true.  It takes many years of schools to learn the basics of a field, and then our careers are spent learning to become experts. For this, and so many other reasons, training is very important.  Example one: developer training leads to better employees.  A company is only as good as the people it employs, and one way to ensure that you have employed the right candidate is through training.  Training can take a regular “stone” and polish it into a “diamond.”  Employees who have been well-trained will be better at their jobs and produce a better product. Most Expensive Resource Did you know that one of the most expensive operating costs for any company is not buying goods, or advertising, but its employees – especially having to hire new employees.  Bringing in new people, getting them up to speed, and providing them with perks to attract them to a company is a huge cost for companies.  So employee retention – keep the employees you already have, and keeping them happy – is incredibly important from a business aspect.  And research shows that a well-trained employee is a happy employee.  They feel more confident in their job, happier with their position, and more cared-about – and therefore less likely to leave in search of a better job.  Employee training leads to better retention. Good Moral On the subject of keeping employees happy in order to keep them at a company, the complement to that research shows that happier employees are more efficient and overall better at their jobs.  You don’t have to be a scientist to figure out why this is true.  An employee who feel that his company cares about him and his educational future will work harder for the company.  He or she will put in that extra hour during the busy season that makes all the difference in the end.  Good morale is good for the company. If good morale is better for the company, you know that it goes hand-in-hand with something even better – better efficiency.  An employee who is well trained obviously knows more about their job and all the technical aspects.  That means when a problem crops up – and they inevitably do – this employee will be well-equipped to deal with that problem with fewer problems, and no need to go searching for help from higher up.  When employees are well trained, companies run more smoothly. A Better Product Of course, all of these “pros” for employee training are leading up to the one thing that companies truly care about – a better product.  We have shown that employees who have been trained to be competitive in the market are happier at the company, they are more efficient, and their morale is better.  The overall result is that the company’s product – whether it is a database, piece of equipment, or even a physical good – is better.  And a better product will always be more competitive on the market. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Developer Training, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Auto Complete and Format T-SQL Code – Devart SQL Complete

  - by pinaldave

  Some people call it laziness, some will call it efficiency, some think it is the right thing to do. At any rate, tools are meant to make a job easier, and I like to use various tools. If we consider the history of the world, if we all wanted to keep traditional practices, we would have never invented the wheel.  But as time progressed, people wanted convenience and efficiency, which then led to laziness. Wanting a more efficient way to do something is not inherently lazy.  That’s how I see any efficiency tools. A few days ago I found Devart SQL Complete.  It took less than a minute to install, and after installation it just worked without needing any tweaking.  Once I started using it I was impressed with how fast it formats SQL code – you can write down any terms or even copy and paste.  You can start typing right away, and it will complete keywords, object names, and fragmentations. It completes statement expressions.  How many times do we write insert, update, delete?  Take this example: to alter a stored procedure name, we don’t remember the code written in it, you have to write it over again, or go back to SQL Server Studio Manager to create and alter which is very difficult.  With SQL Complete , you can write “alter stored procedure,” and it will finish it for you, and you can modify as needed. I love to write code, and I love well-written code.  When I am working with clients, and I find people whose code have not been written properly, I feel a little uncomfortable.  It is difficult to deal with code that is in the wrong case, with no line breaks, no white spaces, improper indents, and no text wrapping.  The worst thing to encounter is code that goes all the way to the right side, and you have to scroll a million times because there are no breaks or indents.  SQL Complete will take care of this for you – if a developer is too lazy for proper formatting, then Devart’s SQL formatter tool will make them better, not lazier. SQL Management Studio gives information about your code when you hover your mouse over it, however SQL Complete goes further in it, going into the work table, and the current rate idea, too. It gives you more information about the parameters; and last but not least, it will just take you to the help file of code navigation.  It will open object explorer in a document viewer.  You can start going through the various properties of your code – a very important thing to do. Here are are interesting Intellisense examples: 1) We are often very lazy to expand *however, when we are using SQL Complete we can just mouse over the * and it will give us all the the column names and we can select the appropriate columns. 2) We can put the cursor after * and it will give us option to expand it to all the column names by pressing the Tab key. 3) Here is one more Intellisense feature I really liked it. I always alias my tables and I always select the alias with special logic. When I was using SQL Complete I selected just a tablename (without schema name) and…(just like below image) … and it autocompleted the schema and alias name (the way I needed it). I believe using SQL Complete we can work faster.  It supports all versions of SQL Server, and works SQL formatting.  Many businesses perform code review and have code standards, so why not use an efficiency tool on everyone’s computer and make sure the code is written correctly from the first time?  If you’re interested in this tool, there are free editions available.  If you like it, you can buy it.  I bought it because it works.  I love it, and I want to hear all your opinions on it, too. You can get the product for FREE.  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 – SOS_SCHEDULER_YIELD – Wait Type – Day 8 of 28

  - by pinaldave

  This is a very interesting wait type and quite often seen as one of the top wait types. Let us discuss this today. From Book On-Line: Occurs when a task voluntarily yields the scheduler for other tasks to execute. During this wait the task is waiting for its quantum to be renewed. SOS_SCHEDULER_YIELD Explanation: SQL Server has multiple threads, and the basic working methodology for SQL Server is that SQL Server does not let any “runnable” thread to starve. Now let us assume SQL Server OS is very busy running threads on all the scheduler. There are always new threads coming up which are ready to run (in other words, runnable). Thread management of the SQL Server is decided by SQL Server and not the operating system. SQL Server runs on non-preemptive mode most of the time, meaning the threads are co-operative and can let other threads to run from time to time by yielding itself. When any thread yields itself for another thread, it creates this wait. If there are more threads, it clearly indicates that the CPU is under pressure. You can fun the following DMV to see how many runnable task counts there are in your system. SELECT scheduler_id, current_tasks_count, runnable_tasks_count, work_queue_count, pending_disk_io_count FROM sys.dm_os_schedulers WHERE scheduler_id < 255 GO If you notice a two-digit number in runnable_tasks_count continuously for long time (not once in a while), you will know that there is CPU pressure. The two-digit number is usually considered as a bad thing; you can read the description of the above DMV over here. Additionally, there are several other counters (%Processor Time and other processor related counters), through which you can refer to so you can validate CPU pressure along with the method explained above. Reducing SOS_SCHEDULER_YIELD wait: This is the trickiest part of this procedure. As discussed, this particular wait type relates to CPU pressure. Increasing more CPU is the solution in simple terms; however, it is not easy to implement this solution. There are other things that you can consider when this wait type is very high. Here is the query where you can find the most expensive query related to CPU from the cache Note: The query that used lots of resources but is not cached will not be caught here. SELECT SUBSTRING(qt.TEXT, (qs.statement_start_offset/2)+1, ((CASE qs.statement_end_offset WHEN -1 THEN DATALENGTH(qt.TEXT) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2)+1), qs.execution_count, qs.total_logical_reads, qs.last_logical_reads, qs.total_logical_writes, qs.last_logical_writes, qs.total_worker_time, qs.last_worker_time, qs.total_elapsed_time/1000000 total_elapsed_time_in_S, qs.last_elapsed_time/1000000 last_elapsed_time_in_S, qs.last_execution_time, qp.query_plan FROM sys.dm_exec_query_stats qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) qt CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp ORDER BY qs.total_worker_time DESC -- CPU time You can find the most expensive queries that are utilizing lots of CPU (from the cache) and you can tune them accordingly. Moreover, you can find the longest running query and attempt to tune them if there is any processor offending code. Additionally, pay attention to total_worker_time because if that is also consistently higher, then  the CPU under too much pressure. You can also check perfmon counters of compilations as they tend to use good amount of CPU. Index rebuild is also a CPU intensive process but we should consider that main cause for this query because that is indeed needed on high transactions OLTP system utilized to reduce fragmentations. 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 of the discussions of Wait Stats in this blog is generic and varies from system to system. It is recommended that you test this on a development server before implementing it to a production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• SQL SERVER – 2012 – All Download Links in Single Page – SQL Server 2012

  - by pinaldave

  SQL Server 2012 RTM is just announced and recently I wrote about all the SQL Server 2012 Certification on single page. As a feedback, I received suggestions to have a single page where everything about SQL Server 2012 is listed. I will keep this page updated as new updates are announced. Microsoft SQL Server 2012 Evaluation Microsoft SQL Server 2012 enables a cloud-ready information platform that will help organizations unlock breakthrough insights across the organization. Microsoft SQL Server 2012 Express Microsoft SQL Server 2012 Express is a powerful and reliable free data management system that delivers a rich and reliable data store for lightweight Web Sites and desktop applications. Microsoft SQL Server 2012 Feature Pack The Microsoft SQL Server 2012 Feature Pack is a collection of stand-alone packages which provide additional value for Microsoft SQL Server 2012. Microsoft SQL Server 2012 Report Builder Report Builder provides a productive report-authoring environment for IT professionals and power users. It supports the full capabilities of SQL Server 2012 Reporting Services. Microsoft SQL Server 2012 Master Data Services Add-in For Microsoft Excel The Master Data Services Add-in for Excel gives multiple users the ability to update master data in a familiar tool without compromising the data’s integrity in Master Data Services. Microsoft SQL Server 2012 Performance Dashboard Reports The SQL Server 2012 Performance Dashboard Reports are Reporting Services report files designed to be used with the Custom Reports feature of SQL Server Management Studio. Microsoft SQL Server 2012 PowerPivot for Microsoft Excel® 2010 Microsoft PowerPivot for Microsoft Excel 2010 provides ground-breaking technology; fast manipulation of large data sets, streamlined integration of data, and the ability to effortlessly share your analysis through Microsoft SharePoint. Microsoft SQL Server 2012 Reporting Services Add-in for Microsoft SharePoint Technologies 2010 The SQL Server 2012 Reporting Services Add-in for Microsoft SharePoint 2010 technologies allows you to integrate your reporting environment with the collaborative SharePoint 2010 experience. Microsoft SQL Server 2012 Semantic Language Statistics The Semantic Language Statistics Database is a required component for the Statistical Semantic Search feature in Microsoft SQL Server 2012 Semantic Language Statistics. Microsoft ®SQL Server 2012 FileStream Driver – Windows Logo Certification Catalog file for Microsoft SQL Server 2012 FileStream Driver that is certified for WindowsServer 2008 R2. It meets Microsoft standards for compatibility and recommended practices with the Windows Server 2008 R2 operating systems. Microsoft SQL Server StreamInsight 2.0 Microsoft StreamInsight is Microsoft’s Complex Event Processing technology to help businesses create event-driven applications and derive better insights by correlating event streams from multiple sources with near-zero latency. Microsoft JDBC Driver 4.0 for SQL Server Download the Microsoft JDBC Driver 4.0 for SQL Server, a Type 4 JDBC driver that provides database connectivity through the standard JDBC application program interfaces (APIs) available in Java Platform, Enterprise Edition 5 and 6. Data Quality Services Performance Best Practices Guide This guide focuses on a set of best practices for optimizing performance of Data Quality Services (DQS). Microsoft Drivers 3.0 for SQL Server for PHP The Microsoft Drivers 3.0 for SQL Server for PHP provide connectivity to Microsoft SQLServer from PHP applications. Product Documentation for Microsoft SQL Server 2012 for firewall and proxy restricted environments The Microsoft SQL Server 2012 setup installs only the Help Viewer…install any documentation. All of the SQL Server documentation is available online. 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 – Error: Fix – Msg 208 – Invalid object name ‘dbo.backupset’ – Invalid object name ‘dbo.backupfile’

  - by pinaldave

  Just a day before I got a very interesting email. Here is the email (modified a bit to make it relevant to this blog post). “Pinal, We are facing a very strange issue. One of our query  related to backup files and backup set has stopped working suddenly in SSMS. It works fine in application where we have and in the stored procedure but when we have it in our SSMS it gives following error. Msg 208, Level 16, State 1, Line 1 Invalid object name ‘dbo.backupfile’. Here are our queries which we are trying to execute. SELECT name, database_name, backup_size, TYPE, compatibility_level, backup_set_id FROM dbo.backupset; SELECT logical_name, backup_size, file_type FROM dbo.backupfile; This query gives us details related to backupset and backup files when the backup was taken.” When I receive this kind of email, usually I have no answers directly. The claim that it works in stored procedure and in application but not in SSMS gives me no real data. I have requested him to very first check following two things: If he is connected to correct server? His answer was yes. If he has enough permissions? His answer was he was logged in as an admin. This means there was something more to it and I requested him to send me a screenshot of the his SSMS. He promptly sends that to me and as soon as I receive the screen shot I knew what was going on. Before I say anything take a look at the screenshot yourself and see if you can figure out why his queries are not working in SSMS. Just to make your life a bit easy, I have already given a hint in the image. The answer is very simple, the context of the database is master database. To execute above two queries the context of the database has to be msdb. Tables backupset and backupfile belong to the database msdb only. Here are two workaround or solution to above problem: 1) Change context to MSDB Above two queries when they will run as following they will not error out and will give the accurate desired result. USE msdb GO SELECT name, database_name, backup_size, TYPE, compatibility_level, backup_set_id FROM dbo.backupset; SELECT logical_name, backup_size, file_type FROM dbo.backupfile; 2) Prefix the query with msdb There are cases above script used in stored procedure or part of big query, it is not possible to change the context of the whole query to any specific database. Use three part naming convention and prefix them with msdb. SELECT name, database_name, backup_size, TYPE, compatibility_level, backup_set_id FROM msdb.dbo.backupset; SELECT logical_name, backup_size, file_type FROM msdb.dbo.backupfile; Very simple solution but sometime keeps people wondering for an answer. 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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• Big Data – Buzz Words: What is MapReduce – Day 7 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned what is Hadoop. In this article we will take a quick look at one of the four most important buzz words which goes around Big Data – MapReduce. What is MapReduce? MapReduce was designed by Google as a programming model for processing large data sets with a parallel, distributed algorithm on a cluster. Though, MapReduce was originally Google proprietary technology, it has been quite a generalized term in the recent time. MapReduce comprises a Map() and Reduce() procedures. Procedure Map() performance filtering and sorting operation on data where as procedure Reduce() performs a summary operation of the data. This model is based on modified concepts of the map and reduce functions commonly available in functional programing. The library where procedure Map() and Reduce() belongs is written in many different languages. The most popular free implementation of MapReduce is Apache Hadoop which we will explore tomorrow. Advantages of MapReduce Procedures The MapReduce Framework usually contains distributed servers and it runs various tasks in parallel to each other. There are various components which manages the communications between various nodes of the data and provides the high availability and fault tolerance. Programs written in MapReduce functional styles are automatically parallelized and executed on commodity machines. The MapReduce Framework takes care of the details of partitioning the data and executing the processes on distributed server on run time. During this process if there is any disaster the framework provides high availability and other available modes take care of the responsibility of the failed node. As you can clearly see more this entire MapReduce Frameworks provides much more than just Map() and Reduce() procedures; it provides scalability and fault tolerance as well. A typical implementation of the MapReduce Framework processes many petabytes of data and thousands of the processing machines. How do MapReduce Framework Works? A typical MapReduce Framework contains petabytes of the data and thousands of the nodes. Here is the basic explanation of the MapReduce Procedures which uses this massive commodity of the servers. Map() Procedure There is always a master node in this infrastructure which takes an input. Right after taking input master node divides it into smaller sub-inputs or sub-problems. These sub-problems are distributed to worker nodes. A worker node later processes them and does necessary analysis. Once the worker node completes the process with this sub-problem it returns it back to master node. Reduce() Procedure All the worker nodes return the answer to the sub-problem assigned to them to master node. The master node collects the answer and once again aggregate that in the form of the answer to the original big problem which was assigned master node. The MapReduce Framework does the above Map () and Reduce () procedure in the parallel and independent to each other. All the Map() procedures can run parallel to each other and once each worker node had completed their task they can send it back to master code to compile it with a single answer. This particular procedure can be very effective when it is implemented on a very large amount of data (Big Data). The MapReduce Framework has five different steps: Preparing Map() Input Executing User Provided Map() Code Shuffle Map Output to Reduce Processor Executing User Provided Reduce Code Producing the Final Output Here is the Dataflow of MapReduce Framework: Input Reader Map Function Partition Function Compare Function Reduce Function Output Writer In a future blog post of this 31 day series we will explore various components of MapReduce in Detail. MapReduce in a Single Statement MapReduce is equivalent to SELECT and GROUP BY of a relational database for a very large database. Tomorrow In tomorrow’s blog post we will discuss Buzz Word – HDFS. 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

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

  - by pinaldave

  Recently I just wrote a blog post on about Learning SQL Server Performance: Indexing Basics and I received lots of request that if we can share some insight into the course. Here is 200 seconds interview of Vinod Kumar I took right after completing the course. We have few free codes to watch the course, please your comment at http://facebook.com/SQLAuth and we will few of first ones, we will send the code. There are many people who said they would like to read the transcript of the video. Here I have generated the same. Pinal: Vinod, we recently released this course, SQL Server Indexing. It is about performance tuning. So tell me – how do indexes help performance? Vinod: I think what happens in the industry when it comes to performance is that developers and DBAs look at indexes first.  So that’s the first step for any performance tuning exercise, indexing is one of the most critical aspects and it is important to learn it the right way. Pinal: Correct. So what you mean to say is that if you know indexing you can pretty much tune any server and query. Vinod: So I might contradict my false statement now. Indexing is usually a stepping stone but it does not lead you to the end. But it’s good to start with indexing and there are lots of nuances to indexing that you need to understand, like how SQL uses indexing and how performance can improve because of the strategies that you have made. Pinal: But now I’m confused. First you said indexes are good, and then you said that indexes can degrade your performance.  So what is this course about?  I mean how does this course really make an impact? Vinod: Ok -so from the course perspective, what we are trying to do is give you a capsule which gives you a good start. Every journey needs a beginning, you need that first step.  This course is that first step in understanding. This is the most basic, fundamental course that we have tried to attack. This is the fundamentals of indexing, some of the key things that you must know about indexing.   Some of the basics of indexing are lesser known and so I think this course is geared towards each and every one of you out there who wants to understand little bit more about indexing. Pinal: So what I understand is that if I enrolled in this course I will have a minimum understanding about indexing when dealing with performance tuning.  Right? Vinod: Exactly. In this course is we have tried to give you a nice summary. We are talking about clustered indexing, non clustered indexing, too many indexes, too few indexes, over indexing, under indexing, duplicate indexing, columns tune indexing, with SQL Server 2012. There’s lot’s to learn. Pinal: You can see the URL [http://bit.ly/sql-index] of the course on the screen. Go ahead, attend, and let us know what you think about it. Thank you. Vinod: Thank you. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology, Video

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