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• SQL SERVER – BACKUPIO, BACKUPBUFFER – Wait Type – Day 14 of 28

  - by pinaldave

  Backup is the most important task for any database admin. Your data is at risk if you are not performing database backup. Honestly, I have seen many DBAs who know how to take backups but do not know how to restore it. (Sigh!) In this blog post we are going to discuss about one of my real experiences with one of my clients – BACKUPIO. When I started to deal with it, I really had no idea how to fix the issue. However, after fixing it at two places, I think I know why this is happening but at the same time, I am not sure the fix is the best solution. The reality is that the fix is not a solution but a workaround (which is not optimal, but get your things done). From Book On-Line: BACKUPIO Occurs when a backup task is waiting for data, or is waiting for a buffer in which to store data. This type is not typical, except when a task is waiting for a tape mount. BACKUPBUFFER Occurs when a backup task is waiting for data, or is waiting for a buffer in which to store data. This type is not typical, except when a task is waiting for a tape mount. BACKUPIO and BACKUPBUFFER Explanation: This wait stats will occur when you are taking the backup on the tape or any other extremely slow backup system. Reducing BACKUPIO and BACKUPBUFFER wait: In my recent consultancy, backup on tape was very slow probably because the tape system was very old. During the time when I explained this wait type reason in the consultancy, the owners immediately decided to replace the tape drive with an alternate system. They had a small SAN enclosure not being used on side, which they decided to re-purpose. After a week, I had received an email from their DBA, saying that the wait stats have reduced drastically. At another location, my client was using a third party tool (please don’t ask me the name of the tool) to take backup. This tool was compressing the backup along with taking backup. I have had a very good experience with this tool almost all the time except this one sparse experience. When I tried to take backup using the native SQL Server compressed backup, there was a very small value on this wait type and the backup was much faster. However, when I attempted with the third party backup tool, this value was very high again and was taking much more time. The third party tool had many other features but the client was not using these features. We end up using the native SQL Server Compressed backup and it worked very well. If I get to see this higher in my future consultancy, I will try to understand this wait type much more in detail and so probably I would able to come to some solid solution. 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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• Framework 4 Features: Login Id Support

  - by Anthony Shorten

  Given that Oracle Utilities Application Framework 4 is available as part of Mobile Work Force Management and other product progressively I am preparing a number of short but sweet blog entries highlighting some of the new functionality that has been implemented. This is the first entry and it is on a new security feature called Login Id. In past releases of the Oracle Utilities Application Framework, the userid used for authentication and authorization was limited to eight (8) characters in length. This mirrored what the market required in the past with LAN userids and even legacy userids being that length. The technology market has since progressed to longer userid lengths. It is very common to hear that email addresses are being used as credentials for production systems. To achieve this in past versions of the Oracle Utilities Application Framework, sites had to introduce a short userid (8 characters in length) as an alias in your preferred security store. You then configured your J2EE Web Application Server to use the alias as credentials. This sometimes was a standard feaure of the security store and/or the J2EE Web Application Server, if you were lucky. If not, some java code has to be written to implement the solution. In Oracle Utilities Application Framework 4 we introduced a new attribute on the user object called Login Id. The Login Id can be up to 256 characters in length and is an alternative to the existing userid stored on the user object. This means the Oracle Utilities Application Framework can support both long and short userids. For backward compatibility we use the Login Id for authentication but the short userid for authorization and auditing. The user object within the Oracle Utilities Application Framework holds the translation. Backward compatibility is always a consideration in any of our designs for future or changed functionality. You will see reference to this fact in the blog entries I will be composing over the next few months. We have also thought about the flexibility in implementing this feature. The Login Id can be the same value of the Userid (the default for backward compatibility) or can be different. Both the Login Id and Userid have to be unique. This avoids sharing of credentials and is also backward compatible. You can manually enter the Login Id or provision it from Oracle Identity Manager (or other tool). If you use the Login Id only, then we will not autogenerate a short userid automatically as the rules for this can vary from site to site. You have a number of options there. Most Identity provisioning tools can generate a short userid at user creation time and this can be used. If you do not use provisioning tools, then you can write a class extension using the SDK to autoegenerate the userid based upon your sites preference. When we designed the feature there were lots of styles of generating userids (random, initial and surname, numbers etc). We could not really see a clear winner in that respect so we just allowed the extension to be inserted in if necessary. Most customers indicated to us that identity provisioning was the preferred way. This is why we released an Oracle Identity Manager integration with the framework. The Login id is case sensitive now which was not supported under userid. The introduction of the Login Id allows the product to offer flexible options when configuring security whilst maintaining backward compatibility.

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• SQLAuthority News – Stay Connected and Social Media

  - by pinaldave

  I think I have finally gotten back my faith in social media. If you are following my blog I am sure you are aware of my views on social media – SQLAuthority News – Social Media Confusion – Twitter, FaceBook, LinkedIn and Me. I was not happy about how social media was evolving. Whenever I go to Twitter, LinkedIn or Facebook, I noticed the same updates everywhere. I just thought I was wasting my time doing the same thing everywhere. I strongly believe that there is no dictator on internet. Nobody has authority over others, everybody can express their ideas as long as it is not violating others privacy and it is not morally wrong. I have decided that instead of trying to improve the world, I should change myself and adjust my needs. Here are few things I have done to relieve my social media confusion. Twitter I un-followed people who were taking up my time with too many updates. I un-followed people who hardly updated at all. I did not follow anybody else’s list, as I have no control over who other people follow. I follow not only serious SQL people but some fun stuff as well. I removed all my friends who were on Facebook and repeating the same updates on Twitter. I engage with them on Facebook. I followed people who are very conversational on Twitter. I let anybody follow me. I update all my blog posts through at least five tweets online. I decided to re-tweet at least five of my favorite tweets of the day, this way I force myself to remain active in the community. Follow me on Twitter! LinkedIn I updated my career and professional info on LinkedIn. I keep my LinkedIn profile updated with my latest jobs and career news. I let anybody connect with me on LinkedIn. I specify my email address in my profile, keeping it easy for those who want to add me. I read all the profile related updates of my connections – it is very valuable to know who is where and what changes are happening. I do not add my personal tweets or comments in LinkedIn profile. I just keep it professional. Link with me at LinkedIn Facebook I use Facebook only for personal friends. I visit all of my friends at regular intervals and make sure that they are really my friends. I often remove my friends from my Twitter list who are sending duplicate updates. I upload my family photos as well as family updates on Facebook, making sure that only my approved friends are able to read my updates. I keep my Facebook very personal and I often chat with my friends on Facebook chat. I am no longer confused about social media and I think I am using it appropriately. As I said, one cannot decide for others how to use social media, you can only decide for yourself. I have finally found my peace with social media. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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

  - by pinaldave

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

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• SQL SERVER – Puzzle #1 – Querying Pattern Ranges and Wild Cards

  - by Pinal Dave

  Note: Read at the end of the blog post how you can get five Joes 2 Pros Book #1 and a surprise gift. I have been blogging for almost 7 years and every other day I receive questions about Querying Pattern Ranges. The most common way to solve the problem is to use Wild Cards. However, not everyone knows how to use wild card properly. SQL Queries 2012 Joes 2 Pros Volume 1 – The SQL Queries 2012 Hands-On Tutorial for Beginners Book On Amazon | Book On Flipkart Learn SQL Server get all the five parts combo kit Kit on Amazon | Kit on Flipkart Many people know wildcards are great for finding patterns in character data. There are also some special sequences with wildcards that can give you even more power. This series from SQL Queries 2012 Joes 2 Pros® Volume 1 will show you some of these cool tricks. All supporting files are available with a free download from the www.Joes2Pros.com web site. This example is from the SQL 2012 series Volume 1 in the file SQLQueries2012Vol1Chapter2.2Setup.sql. If you need help setting up then look in the “Free Videos” section on Joes2Pros under “Getting Started” called “How to install your labs” Querying Pattern Ranges The % wildcard character represents any number of characters of any length. Let’s find all first names that end in the letter ‘A’. By using the percentage ‘%’ sign with the letter ‘A’, we achieve this goal using the code sample below: SELECT * FROM Employee WHERE FirstName LIKE '%A' To find all FirstName values beginning with the letters ‘A’ or ‘B’ we can use two predicates in our WHERE clause, by separating them with the OR statement. Finding names beginning with an ‘A’ or ‘B’ is easy and this works fine until we want a larger range of letters as in the example below for ‘A’ thru ‘K’: SELECT * FROM Employee WHERE FirstName LIKE 'A%' OR FirstName LIKE 'B%' OR FirstName LIKE 'C%' OR FirstName LIKE 'D%' OR FirstName LIKE 'E%' OR FirstName LIKE 'F%' OR FirstName LIKE 'G%' OR FirstName LIKE 'H%' OR FirstName LIKE 'I%' OR FirstName LIKE 'J%' OR FirstName LIKE 'K%' The previous query does find FirstName values beginning with the letters ‘A’ thru ‘K’. However, when a query requires a large range of letters, the LIKE operator has an even better option. Since the first letter of the FirstName field can be ‘A’, ‘B’, ‘C’, ‘D’, ‘E’, ‘F’, ‘G’, ‘H’, ‘I’, ‘J’ or ‘K’, simply list all these choices inside a set of square brackets followed by the ‘%’ wildcard, as in the example below: SELECT * FROM Employee WHERE FirstName LIKE '[ABCDEFGHIJK]%' A more elegant example of this technique recognizes that all these letters are in a continuous range, so we really only need to list the first and last letter of the range inside the square brackets, followed by the ‘%’ wildcard allowing for any number of characters after the first letter in the range. Note: A predicate that uses a range will not work with the ‘=’ operator (equals sign). It will neither raise an error, nor produce a result set. --Bad query (will not error or return any records) SELECT * FROM Employee WHERE FirstName = '[A-K]%' Question: You want to find all first names that start with the letters A-M in your Customer table and end with the letter Z. Which SQL code would you use? a. SELECT * FROM Customer WHERE FirstName LIKE 'm%z' b. SELECT * FROM Customer WHERE FirstName LIKE 'a-m%z' c. SELECT * FROM Customer WHERE FirstName LIKE 'a-m%z' d. SELECT * FROM Customer WHERE FirstName LIKE '[a-m]%z' e. SELECT * FROM Customer WHERE FirstName LIKE '[a-m]z%' f. SELECT * FROM Customer WHERE FirstName LIKE '[a-m]%z' g. SELECT * FROM Customer WHERE FirstName LIKE '[a-m]z%' Contest Leave a valid answer before June 18, 2013 in the comment section. 5 winners will be selected from all the valid answers and will receive Joes 2 Pros Book #1. 1 Lucky person will get a surprise gift from Joes 2 Pros. The contest is open for all the countries where Amazon ships the book (USA, UK, Canada, India and many others). Special Note: Read all the options before you provide valid answer as there is a small trick hidden in answers. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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

  - by pinaldave

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

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• SQL SERVER – Renaming Index – Index Naming Conventions

  - by pinaldave

  If you are regular reader of this blog, you must be aware of that there are two kinds of blog posts 1) I share what I learn recently 2) I share what I learn and request your participation. Today’s blog post is where I need your opinion to make this blog post a good reference for future. Background Story Recently I came across system where users have changed the name of the few of the table to match their new standard naming convention. The name of the table should be self explanatory and they should have explain their purpose without either opening it or reading documentations. Well, not every time this is possible but again this should be the goal of any database modeler. Well, I no way encourage the name of the tables to be too long like ‘ContainsDetailsofNewInvoices’. May be the name of the table should be ‘Invoices’ and table should contain a column with New/Processed bit filed to indicate if the invoice is processed or not (if necessary). Coming back to original story, the database had several tables of which the name were changed. Story Continues… To continue the story let me take simple example. There was a table with the name  ’ReceivedInvoices’, it was changed to new name as ‘TblInvoices’. As per their new naming standard they had to prefix every talbe with the words ‘Tbl’ and prefix every view with the letters ‘Vw’. Personally I do not see any need of the prefix but again, that issue is not here to discuss.  Now after changing the name of the table they faced very interesting situation. They had few indexes on the table which had name of the table. Let us take an example. Old Name of Table: ReceivedInvoice Old Name of Index: Index_ReceivedInvoice1 Here is the new names New Name of Table: TblInvoices New Name of Index: ??? Well, their dilemma was what should be the new naming convention of the Indexes. Here is a quick proposal of the Index naming convention. Do let me know your opinion. If Index is Primary Clustered Index: PK_TableName If Index is  Non-clustered Index: IX_TableName_ColumnName1_ColumnName2… If Index is Unique Non-clustered Index: UX_TableName_ColumnName1_ColumnName2… If Index is Columnstore Non-clustered Index: CL_TableName Here ColumnName is the column on which index is created. As there can be only one Primary Key Index and Columnstore Index per table, they do not require ColumnName in the name of the index. The purpose of this new naming convention is to increase readability. When any user come across this index, without opening their properties or definition, user can will know the details of the index. T-SQL script to Rename Indexes Here is quick T-SQL script to rename Indexes EXEC sp_rename N'SchemaName.TableName.IndexName', N'New_IndexName', N'INDEX'; GO Your Contribute Please Well, the organization has already defined above four guidelines, personally I follow very similar guidelines too. I have seen many variations like adding prefixes CL for Clustered Index and NCL for Non-clustered Index. I have often seen many not using UX prefix for Unique Index but rather use generic IX prefix only. Now do you think if they have missed anything in the coding standard. Is NCI and CI prefixed required to additionally describe the index names. I have once received suggestion to even add fill factor in the index name – which I do not recommend at all. What do you think should be ideal name of the index, so it explains all the most important properties? Additionally, you are welcome to vote if you believe changing the name of index is just waste of time and energy.  Note: The purpose of the blog post is to encourage all to participate with their ideas. I will write follow up blog posts in future compiling all the suggestions. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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

  - by pinaldave

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

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• SQL SERVER – Asynchronous Update and Timestamp – Check if Row Values are Changed Since Last Retrieve

  - by pinaldave

  Here is the question received just this morning. “Pinal, Our application is much different than other application you might have come across. In simple words, I would like to call it Asynchronous Updated Application. We need your quick opinion about one of the situation which we are facing. From business side: We have bidding system (similar to eBay but not exactly) and where multiple parties bid on one item, during the last few minutes of bidding many parties try to bid at the same time with the same price. When they hit submit, we would like to check if the original data which they retrieved is changed or not. If the original data which they have retrieved is the same, we will accept their new proposed price. If original data are changed, they will have to resubmit the data with new price. From technical side: We have a row which we retrieve in our application. Multiple users are retrieving the same row. Some of the users will update the value of the row and submit. However, only the very first user should be allowed to update the row and remaining all the users will have to re-fetch the row and updated it once again. We do not want to lock any record as that will create other problems. Do you have any solution for this kind of situation?” Fantastic Question. I believe there is good chance that we can use timestamp datatype in this kind of application. Before we continue let us see following simple example. USE tempdb GO CREATE TABLE SampleTable (ID INT, Col1 VARCHAR(100), TimeStampCol TIMESTAMP) GO INSERT INTO SampleTable (ID, Col1) VALUES (1, 'FirstVal') GO SELECT ID, Col1, TimeStampCol FROM SampleTable st GO UPDATE SampleTable SET Col1 = 'NextValue' GO SELECT ID, Col1, TimeStampCol FROM SampleTable st GO DROP TABLE SampleTable GO Now let us see the resultset. Here is the simple explanation of the scenario. We created a table with simple column with TIMESTAMP datatype. When we inserted a very first value the timestamp was generated. When we updated any value in that row, the timestamp was updated with the new value. Every single time when we update any value in the row, it will generate new timestamp value. Now let us apply this in an original question’s scenario. In that case multiple users are retrieving the same row. Everybody will have the same now same TimeStamp with them. Before any user update any value they should once again retrieve the timestamp from the table and compare with the timestamp they have with them. If both of the timestamp have the same value – the original row has not been updated and we can safely update the row with the new value. After initial update, now the row will contain a new timestamp. Any subsequent update to the same row should also go to the same process of checking the value of the timestamp they have in their memory. In this case, the timestamp from memory will be different from the timestamp in the row. This indicates that row in the table has changed and new updates should not be allowed. I believe timestamp can be very very useful in this kind of scenario. Is there any better alternative? Please leave a comment with the suggestion and I will post on the blog with due credit. 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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• SQLAuthority News – Speaking at Southeast Asia SharePoint Conference 2013 – Singapore

  - by pinaldave

  Two years ago I spoke at Southeast Asia SharePoint Conference 2011, Singapore and I had a fantastic time to present to the Singapore audience. The session was very well received and lots of interest was generated. The event is back again this year and with much bigger scale. I will be presenting on SQL Server and Sharepoint subject at the conference. Session Details: Title: Performance in 60 Seconds – Database Tricks Every SharePoint Developer & Admin MUST Know Abstract: SharePoint Developers and System Administrators often come across situations where they face a slow server response, even though their hardware specifications are above  par. This session is for all the SharePoint Developers who want their server to perform at blazing fast speed but want to invest very little time to make it happen. We will go over various database tricks which require absolutely no time to master and require practically no SQL coding at all. After attending this session, Developers will only need 60 seconds to improve performance of their database server in their SharePoint implementation. Date and Time: January 18, 20013 - 3:15 PM-4:15 PM Location: Max Atria is located at Singapore Expo, 1 Expo Drive, Singapore Tel 65 6403 2160 This session will cover lots of interesting tips and tricks about SQL Server and SharePoint co-exists together. I promise that every attendee will walk out with a trick which they can walk out of session and directly apply to their production server to improve its performance. The event is going to be again fantastic event – if you are in Singapore – you must not miss this event. If you are planning vacation – this is the right time to take days off and travel to Singapore for vacation. The event features over 30 sessions to choose from, focus on three areas of business gain: Exploring Information, Improving Productivity and Making it Work. This event has an excellent line up of international speakers (speakers traveling from the USA, Australia, New Zealand, Sri Lanka and India). Register early to reserve a spot at your choice of more than 30 classes taught by Microsoft Certified Masters, MVPs, and other top SharePoint experts! Here I have attempted to answer a few of the questions which every SharePoint professional half: Which sessions suit my skill level? Click here. What sessions are right for me? Click here. Which sessions are of my interests? Click here. Which sessions are on when? Click here. If you register by next Friday, 14, December – you can save $126 on the regular price of the conference. Prizes, Giveaways and … I love conference goodies – I collect them as a souvenir . This event is known for its generous prizes. The first 100 people to register on the day will get a SPECIAL gift at the event. Additionally there are exhibitor booth give away too. Here is the page listing all the prizes and giveaways. Do leave a comment or send me email if you are going to the event, we can sit together and have a coffee. 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 – Solution – User Not Able to See Any User Created Object in Tables – Security and Permissions Issue

  - by pinaldave

  There is an old quote “A Picture is Worth a Thousand Words”. I believe this quote immensely. Quite often I get phone calls that something is not working if I can help. My reaction is in most of the cases, I need to know more, send me exact error or a screenshot. Until and unless I see the error or reproduce the scenario myself I prefer not to comment. Yesterday I got a similar phone call from an old friend, where he was not sure what is going on. Here is what he said. “When I try to connect to SQL Server, it lets me connect just fine as well let me open and explore the database. I noticed that I do not see any user created instances but when my colleague attempts to connect to the server, he is able to explore the database as well see all the user created tables and other objects. Can you help me fix it? “ My immediate reaction was he was facing security and permission issue. However, to make the same recommendation I suggested that he send me a screenshot of his own SSMS and his friend’s SSMS. After carefully looking at both the screenshots, I was very confident about the issue and we were able to resolve the issue. Let us reproduce the same scenario and many there is some learning for us. Issue: User not able to see user created objects First let us see the image of my friend’s SSMS screen. (Recreated on my machine) Now let us see my friend’s colleague SSMS screen. (Recreated on my machine) You can see that my friend could not see the user tables but his colleague was able to do the same for sure. Now I believed it was a permissions issue. Further to this I asked him to send me another image where I can see the various permissions of the user in the database. My friends screen My friends colleagues screen This indeed proved that my friend did not have access to the AdventureWorks database and because of the same he was not able to access the database. He did have public access which means he will have similar rights as guest access. However, their SQL Server had followed my earlier advise on having limited access for guest access, which means he was not able to see any user created objects. My next question was to validate what kind of access my friend’s colleague had. He replied that the colleague is the admin of the server. I suggested that if my friend was suppose to have admin access to the database, he should request of having admin access to his colleague. My friend promptly asked for the same to his colleague and on following screen he added him as an admin. You can do the same using following T-SQL script as well. USE [AdventureWorks2012] GO ALTER ROLE [db_owner] ADD MEMBER [testguest] GO Once my friend was admin he was able to access all the user objects just like he was expecting. Please note, this complete exercise was done on a development server. One should not play around with security on live or production server. Security is such an issue, which should be left with only senior administrator of the server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Configuring Interactive Cleansing Suggestion Min Score for Suggestions in Data Quality Services (DQS) – Sensitivity of Suggestion

  - by pinaldave

  Earlier I talked about what kind of questions, I do not like when I get asked. Today we will go over the question which I like when I get asked the same. One of the reader practices various steps in my earlier blog post Step by Step Guide to Beginning Data Quality Services in SQL Server 2012 – Introduction to DQS. While reading the blog post he noticed that Data Quality Services is not providing very helpful suggestions. He wrote an email to me about it. Let us go over his email. “Pinal, I noticed in one of your images that DQS is not providing very helpful suggestions. First of all DQS should be able to make intelligent guesses and make the necessary correction by itself. If it cannot do the same, in that case, it should give us intelligent suggestions but in the image included here, I see the suggestions are not there as well. Why is it so? Would you please tell me how to increase the numbers of suggestion? I do understand this may not be preferable solution in many case but all the business cases go on it depends. There are cases when the high sensitivity required and there are cases when higher sensitivities are not required. I would like to seek your help here. –Sriram MD” This is indeed a great question. I see that Sriram understands that every system is different and every application has a different need. I will not have to tell him this most important concept. The question is about how to change the sensitivity of suggestions for correction in DQS. Well, this option is available under the configuration tab in the DQS client. Once you click on Configuration you will see the following screen. Click the Tab of General Settings. You will see the section of Interactive Cleansing. Under this second there is the first option of “Min score for suggestions”. As this is set to 0.7 every suggestion which matches 0.7 probabilities or higher probability are displayed under the suggestion tab. You can see in the following image that there is no suggestion as the min score for suggestions is set to 0.7 and there is no record which qualifies to that much confidence. Now let us change the value of Min Score for suggestion to 0.5. The lower value increased the confidence of DQS to give further suggestion to values which are over 0.5. However, in our case the suggestions which it provides are also accurate. This may not be true for your sample. Every sample is different so you should manually review it before approving them. I guess, this is a simple blog post to demonstrate how to change the confidence value for the suggestions which Data Quality Services provides. Use this feature with care and always tune it according to your datasets and record diversity. Reference: Pinal Dave (http://blog.SQLAuthority.com)       Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Data Quality Services, DQS

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• SQL SERVER – Finding Different ColumnName From Almost Identitical Tables

  - by pinaldave

  I have mentioned earlier on this blog that I love social media – Facebook and Twitter. I receive so many interesting questions that sometimes I wonder how come I never faced them in my real life scenario. Well, let us see one of the similar situation. Here is one of the questions which I received on my social media handle. “Pinal, I have a large database. I did not develop this database but I have inherited this database. In our database we have many tables but all the tables are in pairs. We have one archive table and one current table. Now here is interesting situation. For a while due to some reason our organization has stopped paying attention to archive data. We did not archive anything for a while. If this was not enough we  even changed the schema of current table but did not change the corresponding archive table. This is now becoming a huge huge problem. We know for sure that in current table we have added few column but we do not know which ones. Is there any way we can figure out what are the new column added in the current table and does not exist in the archive tables? We cannot use any third party tool. Would you please guide us?” Well here is the interesting example of how we can use sys.column catalogue views and get the details of the newly added column. I have previously written about EXCEPT over here which is very similar to MINUS of Oracle. In following example we are going to create two tables. One of the tables has extra column. In our resultset we will get the name of the extra column as we are comparing the catalogue view of the column name. USE AdventureWorks2012 GO CREATE TABLE ArchiveTable (ID INT, Col1 VARCHAR(10), Col2 VARCHAR(100), Col3 VARCHAR(100)); CREATE TABLE CurrentTable (ID INT, Col1 VARCHAR(10), Col2 VARCHAR(100), Col3 VARCHAR(100), ExtraCol INT); GO -- Columns in ArchiveTable but not in CurrentTable SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'ArchiveTable' EXCEPT SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'CurrentTable' GO -- Columns in CurrentTable but not in ArchiveTable SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'CurrentTable' EXCEPT SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'ArchiveTable' GO DROP TABLE ArchiveTable; DROP TABLE CurrentTable; GO The above query will return us following result. I hope this solves the problems. It is not the most elegant solution ever possible but it works. Here is the puzzle back to you – what native T-SQL solution would you have provided in this situation? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL System Table, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Last Two Days to Get FREE Book – Joes 2 Pros Certification 70-433

  - by pinaldave

  Earlier this week we announced that we will be giving away FREE SQL Wait Stats book to everybody who will get SQL Server Joes 2 Pros Combo Kit. We had a fantastic response to the contest. We got an overwhelming response to the offer. We knew there would be a great response but we want to honestly say thank you to all of you for making it happen. Rick and I want to make sure that we express our special thanks to all of you who are reading our books. The offer is still on and there are two more days to avail this offer. We want to make sure that everybody who buys our most selling combo kits, we will send our other most popular SQL Wait Stats book. Please read all the details of the offer here. The books are great resources for anyone who wants to learn SQL Server from fundamentals and eventually go on the certification path of 70-433. Exam 70-433 contains following important subject and the book covers the subject of fundamental. If you are taking the exam or not taking the exam – this book is for every SQL Developer to learn the subject from fundamentals.  Create and alter tables. Create and alter views. Create and alter indexes. Create and modify constraints. Implement data types. Implement partitioning solutions. Create and alter stored procedures. Create and alter user-defined functions (UDFs). Create and alter DML triggers. Create and alter DDL triggers. Create and deploy CLR-based objects. Implement error handling. Manage transactions. Query data by using SELECT statements. Modify data by using INSERT, UPDATE, and DELETE statements. Return data by using the OUTPUT clause. Modify data by using MERGE statements. Implement aggregate queries. Combine datasets. INTERSECT, EXCEPT Implement subqueries. Implement CTE (common table expression) queries. Apply ranking functions. Control execution plans. Manage international considerations. Integrate Database Mail. Implement full-text search. Implement scripts by using Windows PowerShell and SQL Server Management Objects (SMOs). Implement Service Broker solutions. Track data changes. Data capture Retrieve relational data as XML. Transform XML data into relational data. Manage XML data. Capture execution plans. Collect output from the Database Engine Tuning Advisor. Collect information from system metadata. Availability of Book 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, T SQL, Technology

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• SQLAuthority News – Advantages of Distance Learning

  - by Pinal Dave

  Distance education is extremely popular – almost overnight, it seems.  Almost everyone has taken an online course, or knows someone who has, or is considering joining an online school.  There are many advantages and disadvantages to attending an online school – but the same can be said of attending a physical school!  Let’s take a look at the top reasons to use distance education. 1) Flexibility.  Physical universities are usually willing to make some concessions to student – like night classes, study hours, and online networks.  However, nothing is going to beat the flexibility of distance education.  You can attend classes and take notes anytime, anywhere, wearing anything you’d like! 2) Affordability.  We don’t need to get into hard numbers to understand how an expensive university can be.  Students are taking on more and more debt just to get an education.  Many of these fees pay for room, board, and facilities.   Distance education cuts out all these costs, and makes attending school much more affordable for the average student. 3) Try before you buy.  Did you know that the average college student changes his or her major 10 times before they graduate?  You can imagine that this kind of indecision plays a huge part in WHEN you graduate – not being able to make up your mind can cost you big bucks if you have to stay in school for extra years!  Distance education allows you to take different classes from a wide range of disciplines.  Do you want to study forensic science or English literature?  Now you don’t have to pay for classes you can’t afford just to find out. 4) Pace yourself.  Some students struggle in a traditional classroom setting – classes can be taught too fast, too slow, or there are too many distractions.  Distance education allows mature students to set the pace themselves.  They can rewatch lectures they didn’t catch the first time, or go through classes quickly if they are already familiar with the material – cutting out the chance of burning out or getting bored. 5) Lifelong learning.  Maybe you already have a degree, but would like to learn more about your field, or a related field, or maybe even about something completely unrelated – just because you are curious!  Distance education allows you to learn whatever you want ,whenever you want (and yes, wearing anything you’d like!). 6) Attend whatever college you want.  Because of the popularity of distance education, physical campuses are getting in on the game by offering online courses – often just uploaded versions of classes already taught at their campus.  Ever wanted to attend Harvard, but knew you couldn’t get in?  Take a class online!  Of course, you probably should not attempt to lie and say you have a Harvard degree, but Ivy League colleges are prestigious because they are the best in their field – take advantage of the best by taking an online course! I am a big believer in continuing education, whether it is online courses, returning to school, or even take informal classes online.  Distance education can be a great way to accomplish these goals and become a lifelong learner. My friends at provides training through virtual classrooms for students who want to avoid travelling. Distance learning course allows IT aspirants to connect with trainers using the internet.  I encourage everyone to check it out! Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Training, T SQL, Technology

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• SQL SERVER – Importance of User Without Login

  - by pinaldave

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

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• SQL SERVER – Unable to DELETE Project in Data Quality Projects (DQS)

  - by pinaldave

  Here is the email which made me write this blog post. When I write a blog post I write keeping in mind that if the developer is not familiar with the concept he will attempt this on the development server. If due to any reason you attempt it on any other server than your personal server, developer should make sure to have complete confidence on his own expertise and understand the risk behind it.  Well, let us read the email which I received. I have modified it a bit to remove information related to organizational and individual. “I just read your blog post on Beginning DQS. I went ahead and followed every single screenshot and it worked fine. I was able to execute the DQS project successfully. However, the same blog post got me in trouble – a serious trouble. After first successful deployment I went ahead and created a few of my own knowledge base and projects. I played around a bit and then decided to get back to real work. Now we had deployed DQS on production server only, so experiment on production server. Now, when I got back to my work, I forgot to close all the windows. My manager found the window open and have seen my test projects. He has asked me to delete my experiments immediately and have said words which I cannot write to you. Here is the problem. I am not able to delete the project which I have created earlier. I am able to open it and play with it but the delete option is disabled and grayed out (see attached image). Now I believe there is nothing wrong with this project as it was just a test project. Would you please write to my manager that it is not harmful to leave that project there as it is? It is also not using any resources. I think he will believe you.” As I said this kind of email makes me uncomfortable. I do not want someone to execute anything on production server. I often write notes and disclaimer on my post when something is dangerous to execute on production server. However, if someone is not expert with SQL Server and attempts something new on production server, I think the major issue is here with the person (admin) who gave new developer permission to production server. This has to be carefully avoided. Here was my response to the individual. “I cannot write to your manager anything as he has not asked me anything. Honestly I believe he is correct in his behavior as you should have not executed anything on the production server without prior approval and testing on the development server. Any R&D must be done on local box or development box. I suggest you request your manager to prevent access to users who does not need access. If he is a good manager, he might have already implemented by now recent event. I also see your screenshot. Here is the issue: While you were playing with project, you might have closed the project half the way, without completing it. Due to the same reason it is locked. You can open and continue from the same place where you have left the project. If you do not need the project any more. Right click on it, click on unlock the project. This will enable the DELETE option and now you can delete the project. Next time, be safe out there. It may be dangerous to have admin access to production server when not needed.“ I have yet not heard from him but I believe he will take my words positively. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Data Quality Services, DQS

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• SQL SERVER – Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – T-SQL Example – Part 2 of 2

  - by pinaldave

  Yesterday I wrote a real world story of how a friend who thought they have an issue with intrusion or virus whereas the issue was really in the code. I strongly suggest you read my earlier blog post Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – Part 1 of 2 before continuing this blog post as this is second part of the first blog post. Let me reproduce the simple scenario in T-SQL. Building Sample Data USE [TestDB] GO -- Creating Table Products CREATE TABLE [dbo].[Products]( [ProductID] [int] NOT NULL, [ProductDesc] [varchar](50) NOT NULL, CONSTRAINT [PK_Products] PRIMARY KEY CLUSTERED ( [ProductID] ASC )) ON [PRIMARY] GO -- Creating Table ProductDetails CREATE TABLE [dbo].[ProductDetails]( [ProductDetailID] [int] NOT NULL, [ProductID] [int] NOT NULL, [Total] [int] NOT NULL, CONSTRAINT [PK_ProductDetails] PRIMARY KEY CLUSTERED ( [ProductDetailID] ASC )) ON [PRIMARY] GO ALTER TABLE [dbo].[ProductDetails] WITH CHECK ADD CONSTRAINT [FK_ProductDetails_Products] FOREIGN KEY([ProductID]) REFERENCES [dbo].[Products] ([ProductID]) ON UPDATE CASCADE ON DELETE CASCADE GO -- Insert Data into Table USE TestDB GO INSERT INTO Products (ProductID, ProductDesc) SELECT 1, 'Bike' UNION ALL SELECT 2, 'Car' UNION ALL SELECT 3, 'Books' GO INSERT INTO ProductDetails ([ProductDetailID],[ProductID],[Total]) SELECT 1, 1, 200 UNION ALL SELECT 2, 1, 100 UNION ALL SELECT 3, 1, 111 UNION ALL SELECT 4, 2, 200 UNION ALL SELECT 5, 3, 100 UNION ALL SELECT 6, 3, 100 UNION ALL SELECT 7, 3, 200 GO Select Data from Tables -- Selecting Data SELECT * FROM Products SELECT * FROM ProductDetails GO Delete Data from Products Table -- Deleting Data DELETE FROM Products WHERE ProductID = 1 GO Select Data from Tables Again -- Selecting Data SELECT * FROM Products SELECT * FROM ProductDetails GO Clean up Data -- Clean up DROP TABLE ProductDetails DROP TABLE Products GO My friend was confused as there was no delete was firing over ProductsDetails Table still there was a delete happening. The reason was because there is a foreign key created between Products and ProductsDetails Table with the keywords ON DELETE CASCADE. Due to ON DELETE CASCADE whenever is specified when the data from Table A is deleted and if it is referenced in another table using foreign key it will be deleted as well. Workaround 1: Design Changes – 3 Tables Change the design to have more than two tables. Create One Product Mater Table with all the products. It should historically store all the products list in it. No products should be ever removed from it. Add another table called Current Product and it should contain only the table which should be visible in the product catalogue. Another table should be called as ProductHistory table. There should be no use of CASCADE keyword among them. Workaround 2: Design Changes - Column IsVisible You can keep the same two tables. 1) Products and 2) ProductsDetails. Add a column with BIT datatype to it and name it as a IsVisible. Now change your application code to display the catalogue based on this column. There should be no need to delete anything. Workaround 3: Bad Advices (Bad advises begins here) The reason I have said bad advices because these are going to be bad advices for sure. You should make necessary design changes and not use poor workarounds which can damage the system and database integrity further. Here are the examples 1) Do not delete the data – well, this is not a real solution but can give time to implement design changes. 2) Do not have ON CASCADE DELETE – in this case, you will have entry in productsdetails which will have no corresponding product id and later on there will be lots of confusion. 3) Duplicate Data – you can have all the data of the product table move to the product details table and repeat them at each row. Now remove CASCADE code. This will let you delete the product table rows without any issue. There are so many things wrong this suggestion, that I will not even start here. (Bad advises ends here)  Well, did I miss anything? Please help me with your suggestions. 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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• What language/framework (technology) to use for website (flash games portal)

  - by cripox

  Hello, I know there are a lot of similar questions on the net, but because I am a newbie in web development I didn't find the solution for my specific problem. I am planing on creating a flash games portal from scratch. It is a big chance that there will be big traffic from the beginning (millions of pageviews). I want to reduce the server costs as much as possible but in the same time to not be tide to an expensive contract as there is a chance that the project will not be as successfully as I want and in that case the money would be very little. The question is : what technology to use? I don't know any web dev technology yet so it doesn't matter what I will learn. My web dev experience is a little php 8 years ago, and from then I programmed in C++ / Java- game and mobile development. I like Java and C syntax and language very much and I tend to dislike dynamic typing or non robust scripting (like php)- but I can get along if these are the best choices. The candidates are now: - Grails (my best for now) Ruby on Rails Cake PHP Other technologies (Google App Engine, Python/Django etc...) I was considering at first using pure C and compiling the web app in the server- just to squeeze more from the servers, but soon I understand that this is overkill. Next my eyes came on Ruby - as there is a lot of buzz for it's easiness of use. Next I discovered Grails and looked at Java because it is said that it is "faster". But I don't know what this "Faster" really means on my needs, so here comes the first question: 1) What will be my biggest consumption on the server, other than bandwidth, for a lot of flash content requests? Is it memory? I heard that Java needs a lot of memory, but is faster. Is it CPU? I am planning to take some daily VPS.NET nodes at first, to see if there is a demand, and if the "spike" is permanent to move to a dedicated server (serverloft.com has some good offers), else to remain with less nodes. I was also considering developing in Google App Engine- cheap or free hosting to use at first - so I can test my assumption- and also very easy to use (no need for sys administration) but the costs became high if used more ( 3 million games played / month .. x mb/ each). And the issue with Google is that it looks me in this technology. My other concern is scalability (not only for traffic/users, but as adding functionality) My plans are to release a functional site in just 4 weeks (just the basics frontend and some quick basic backend - so I can be able to modify some things and add games manually) - but then to raise it and add more things to it. I am planning to take a little different approach than other portals so I need to write it from scratch (a script will not do). 2) Will Grails take much more resources than RoR or Php server wise? I heard that making it on Java stack will be hardware expensive and is overkill if you don't make a bank application. My application will not be very complex (I hope and i will try to) but will have a lot of traffic. I also took in account using CDN for files, but the cheapest CDN found was 5c/GB (vps.net) and the cost per gb on serverloft (http://www.serverloft.com/dedizierte-server/server-details.php?products=4) is only 1.79 cents/GB and comes with the other resources either. I am new to this domain (web). I am learning the ropes and searching on the web for ~half of year but don't have any really practical experience, so I know that I must have some naive thinking and other issues that i don't know from now, so please give me any advice you want regarding anything, not just the specific questions asked. And thank you so much for such great community!

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• SQL SERVER – Retrieve and Explore Database Backup without Restoring Database – Idera virtual databas

  - by pinaldave

  I recently downloaded Idera’s SQL virtual database, and tested it. There are a few things about this tool which caught my attention. My Scenario It is quite common in real life that sometimes observing or retrieving older data is necessary; however, it had changed as time passed by. The full database backup was 40 GB in size, and, to restore it on our production server, it usually takes around 16 to 22 minutes, depending on the load server that is usually present. This range in time varies from one server to another as per the configuration of the computer. Some other issues we used to have are the following: When we try to restore a large 40-GB database, we needed at least that much space on our production server. Once in a while, we even had to make changes in the restored database, and use the said changed and restored database for our purpose, making it more time-consuming. My Solution I have heard a lot about the Idera’s SQL virtual database tool.. Well, right after we started to test this tool, we found out that it really delivers what it promises. Using this software was very easy and we were able to restore our database from backup in less than 2 minutes, sparing us from the usual longer time of 16–22 minutes. The needful was finished in a total of 10 minutes. Another interesting observation is that there is no need to have an additional space for restoring the database. For complete database restoration, the single additional MB on the drive is not required anymore. We can use the database in the same way as our regular database, and there is no need for any additional configuration and setup. Let us look at the most relevant points of this product based on my initial experience: Quick restoration of the database backup No additional space required for database restoration virtual database has no physical .MDF or .LDF The database which is restored is, in fact, the backup file converted in the virtual database. DDL and DML queries can be executed against this virtually restored database. Regular backup operation can be implemented against virtual database, creating a physical .bak file that can be used for future use. There was no observed degradation in performance on the original database as well the restored virtual database. Additional T-SQL queries can be let off on the virtual database. Well, this summarizes my quick review. And, as I was saying, I am very impressed with the product and I plan to explore it more. There are many features that I have noticed in this tool, which I think can be very useful if properly understood. I had taken a few screenshots using my demo database afterwards. Let us see what other things this tool can do besides the mentioned activities. I am surprised with its performance so I want to know how exactly this feature works, specifically in the matter of why it does not create any additional files and yet, it still allows update on the virtually restored database. I guess I will have to send an e-mail to the developers of Idera and try to figure this out from them. I think this tool is very useful, and it delivers a high level of performance way more than what I expected. Soon, I will write a review for additional uses of SQL virtual database.. If you are using SQL virtual database in your production environment, I am eager to learn more about it and your experience while using it. The ‘Virtual’ Part of virtual database When I set out to test this software, I thought virtual database had something to do with Hyper-V or visualization. In fact, the virtual database is a kind of database which shows up in your SQL Server Management Studio without actually restoring or even creating it. This tool creates a database in SSMS from the backup of the same database. The backup, however, works virtually the same way as original database. Potential Usage of virtual database: As soon as I described this tool to my teammate, I think his very first reaction was, “hey, if we have this then there is no need for log shipping.” I find his comment very interesting as log shipping is something where logs are moved to another server. In fact, there are no updates on the database from log; I would rather compare it with Snapshot Replication. In fact, whatever we use, snapshot replicated database can be similarly used and configured with virtual database. I totally believe that we can use it for reporting purpose. In fact, after this database was configured, I think the uses of this tool are unlimited. I will have to spend some more time studying it and will get back to you. Click on images to see larger images. virtual database Console Harddrive Space before virtual database Setup Attach Full Backup Screen Backup on Harddrive Attach Full Backup Screen with Settings virtual database Setup – less than 60 sec virtual database Setup – Online Harddrive Space after virtual database Setup Point in Time Recovery Option – Timeline View virtual database Summary No Performance Difference between Regular DB vs Virtual DB Please note that all SQL Server MVP gets free license of this software. Reference: Pinal Dave (http://blog.SQLAuthority.com), Idera (virtual database) Filed under: Database, Pinal Dave, SQL, SQL Add-On, SQL Authority, SQL Backup and Restore, SQL Data Storage, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, SQLAuthority News, T SQL, Technology Tagged: Idera

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• SQL SERVER – 2008 – Introduction to Snapshot Database – Restore From Snapshot

  - by pinaldave

  Snapshot database is one of the most interesting concepts that I have used at some places recently. Here is a quick definition of the subject from Book On Line: A Database Snapshot is a read-only, static view of a database (the source database). Multiple snapshots can exist on a source database and can always reside on the same server instance as the database. Each database snapshot is consistent, in terms of transactions, with the source database as of the moment of the snapshot’s creation. A snapshot persists until it is explicitly dropped by the database owner. If you do not know how Snapshot database work, here is a quick note on the subject. However, please refer to the official description on Book-on-Line for accuracy. Snapshot database is a read-only database created from an original database called the “source database”. This database operates at page level. When Snapshot database is created, it is produced on sparse files; in fact, it does not occupy any space (or occupies very little space) in the Operating System. When any data page is modified in the source database, that data page is copied to Snapshot database, making the sparse file size increases. When an unmodified data page is read in the Snapshot database, it actually reads the pages of the original database. In other words, the changes that happen in the source database are reflected in the Snapshot database. Let us see a simple example of Snapshot. In the following exercise, we will do a few operations. Please note that this script is for demo purposes only- there are a few considerations of CPU, DISK I/O and memory, which will be discussed in the future posts. Create Snapshot Delete Data from Original DB Restore Data from Snapshot First, let us create the first Snapshot database and observe the sparse file details. USE master GO -- Create Regular Database CREATE DATABASE RegularDB GO USE RegularDB GO -- Populate Regular Database with Sample Table CREATE TABLE FirstTable (ID INT, Value VARCHAR(10)) INSERT INTO FirstTable VALUES(1, 'First'); INSERT INTO FirstTable VALUES(2, 'Second'); INSERT INTO FirstTable VALUES(3, 'Third'); GO -- Create Snapshot Database CREATE DATABASE SnapshotDB ON (Name ='RegularDB', FileName='c:\SSDB.ss1') AS SNAPSHOT OF RegularDB; GO -- Select from Regular and Snapshot Database SELECT * FROM RegularDB.dbo.FirstTable; SELECT * FROM SnapshotDB.dbo.FirstTable; GO Now let us see the resultset for the same. Now let us do delete something from the Original DB and check the same details we checked before. -- Delete from Regular Database DELETE FROM RegularDB.dbo.FirstTable; GO -- Select from Regular and Snapshot Database SELECT * FROM RegularDB.dbo.FirstTable; SELECT * FROM SnapshotDB.dbo.FirstTable; GO When we check the details of sparse file created by Snapshot database, we will find some interesting details. The details of Regular DB remain the same. It clearly shows that when we delete data from Regular/Source DB, it copies the data pages to Snapshot database. This is the reason why the size of the snapshot DB is increased. Now let us take this small exercise to  the next level and restore our deleted data from Snapshot DB to Original Source DB. -- Restore Data from Snapshot Database USE master GO RESTORE DATABASE RegularDB FROM DATABASE_SNAPSHOT = 'SnapshotDB'; GO -- Select from Regular and Snapshot Database SELECT * FROM RegularDB.dbo.FirstTable; SELECT * FROM SnapshotDB.dbo.FirstTable; GO -- Clean up DROP DATABASE [SnapshotDB]; DROP DATABASE [RegularDB]; GO Now let us check the details of the select statement and we can see that we are successful able to restore the database from Snapshot Database. We can clearly see that this is a very useful feature in case you would encounter a good business that needs it. I would like to request the readers to suggest more details if they are using this feature in their business. Also, let me know if you think it can be potentially used to achieve any tasks. Complete Script of the afore- mentioned operation for easy reference is as follows: USE master GO -- Create Regular Database CREATE DATABASE RegularDB GO USE RegularDB GO -- Populate Regular Database with Sample Table CREATE TABLE FirstTable (ID INT, Value VARCHAR(10)) INSERT INTO FirstTable VALUES(1, 'First'); INSERT INTO FirstTable VALUES(2, 'Second'); INSERT INTO FirstTable VALUES(3, 'Third'); GO -- Create Snapshot Database CREATE DATABASE SnapshotDB ON (Name ='RegularDB', FileName='c:\SSDB.ss1') AS SNAPSHOT OF RegularDB; GO -- Select from Regular and Snapshot Database SELECT * FROM RegularDB.dbo.FirstTable; SELECT * FROM SnapshotDB.dbo.FirstTable; GO -- Delete from Regular Database DELETE FROM RegularDB.dbo.FirstTable; GO -- Select from Regular and Snapshot Database SELECT * FROM RegularDB.dbo.FirstTable; SELECT * FROM SnapshotDB.dbo.FirstTable; GO -- Restore Data from Snapshot Database USE master GO RESTORE DATABASE RegularDB FROM DATABASE_SNAPSHOT = 'SnapshotDB'; GO -- Select from Regular and Snapshot Database SELECT * FROM RegularDB.dbo.FirstTable; SELECT * FROM SnapshotDB.dbo.FirstTable; GO -- Clean up DROP DATABASE [SnapshotDB]; DROP DATABASE [RegularDB]; GO Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: SQL, SQL Authority, SQL Backup and Restore, SQL Data Storage, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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• SQL SERVER – Signal Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

  - by pinaldave

  In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Signal Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Signal Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Signal Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the Signalwait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the Signal wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the Signal wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL 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 – Enumerations in Relational Database – Best Practice

  - by pinaldave

  Marko Parkkola This article has been submitted by Marko Parkkola, Data systems designer at Saarionen Oy, Finland. Marko is excellent developer and always thinking at next level. You can read his earlier comment which created very interesting discussion here: SQL SERVER- IF EXISTS(Select null from table) vs IF EXISTS(Select 1 from table). I must express my special thanks to Marko for sending this best practice for Enumerations in Relational Database. He has really wrote excellent piece here and welcome comments here. Enumerations in Relational Database This is a subject which is very basic thing in relational databases but often not very well understood and sometimes badly implemented. There are of course many ways to do this but I concentrate only two cases, one which is “the right way” and one which is definitely wrong way. The concept Let’s say we have table Person in our database. Person has properties/fields like Firstname, Lastname, Birthday and so on. Then there’s a field that tells person’s marital status and let’s name it the same way; MaritalStatus. Now MaritalStatus is an enumeration. In C# I would definitely make it an enumeration with values likes Single, InRelationship, Married, Divorced. Now here comes the problem, SQL doesn’t have enumerations. The wrong way This is, in my opinion, absolutely the wrong way to do this. It has one upside though; you’ll see the enumeration’s description instantly when you do simple SELECT query and you don’t have to deal with mysterious values. There’s plenty of downsides too and one would be database fragmentation. Consider this (I’ve left all indexes and constraints out of the query on purpose). CREATE TABLE [dbo].[Person] ( [Firstname] NVARCHAR(100), [Lastname] NVARCHAR(100), [Birthday] datetime, [MaritalStatus] NVARCHAR(10) ) You have nvarchar(20) field in the table that tells the marital status. Obvious problem with this is that what if you create a new value which doesn’t fit into 20 characters? You’ll have to come and alter the table. There are other problems also but I’ll leave those for the reader to think about. The correct way Here’s how I’ve done this in many projects. This model still has one problem but it can be alleviated in the application layer or with CHECK constraints if you like. First I will create a namespace table which tells the name of the enumeration. I will add one row to it too. I’ll write all the indexes and constraints here too. CREATE TABLE [CodeNamespace] ( [Id] INT IDENTITY(1, 1), [Name] NVARCHAR(100) NOT NULL, CONSTRAINT [PK_CodeNamespace] PRIMARY KEY ([Id]), CONSTRAINT [IXQ_CodeNamespace_Name] UNIQUE NONCLUSTERED ([Name]) ) GO INSERT INTO [CodeNamespace] SELECT 'MaritalStatus' GO Then I create a table that holds the actual values and which reference to namespace table in order to group the values under different namespaces. I’ll add couple of rows here too. CREATE TABLE [CodeValue] ( [CodeNamespaceId] INT NOT NULL, [Value] INT NOT NULL, [Description] NVARCHAR(100) NOT NULL, [OrderBy] INT, CONSTRAINT [PK_CodeValue] PRIMARY KEY CLUSTERED ([CodeNamespaceId], [Value]), CONSTRAINT [FK_CodeValue_CodeNamespace] FOREIGN KEY ([CodeNamespaceId]) REFERENCES [CodeNamespace] ([Id]) ) GO -- 1 is the 'MaritalStatus' namespace INSERT INTO [CodeValue] SELECT 1, 1, 'Single', 1 INSERT INTO [CodeValue] SELECT 1, 2, 'In relationship', 2 INSERT INTO [CodeValue] SELECT 1, 3, 'Married', 3 INSERT INTO [CodeValue] SELECT 1, 4, 'Divorced', 4 GO Now there’s four columns in CodeValue table. CodeNamespaceId tells under which namespace values belongs to. Value tells the enumeration value which is used in Person table (I’ll show how this is done below). Description tells what the value means. You can use this, for example, column in UI’s combo box. OrderBy tells if the values needs to be ordered in some way when displayed in the UI. And here’s the Person table again now with correct columns. I’ll add one row here to show how enumerations are to be used. CREATE TABLE [dbo].[Person] ( [Firstname] NVARCHAR(100), [Lastname] NVARCHAR(100), [Birthday] datetime, [MaritalStatus] INT ) GO INSERT INTO [Person] SELECT 'Marko', 'Parkkola', '1977-03-04', 3 GO Now I said earlier that there is one problem with this. MaritalStatus column doesn’t have any database enforced relationship to the CodeValue table so you can enter any value you like into this field. I’ve solved this problem in the application layer by selecting all the values from the CodeValue table and put them into a combobox / dropdownlist (with Value field as value and Description as text) so the end user can’t enter any illegal values; and of course I’ll check the entered value in data access layer also. I said in the “The wrong way” section that there is one benefit to it. In fact, you can have the same benefit here by using a simple view, which I schema bound so you can even index it if you like. CREATE VIEW [dbo].[Person_v] WITH SCHEMABINDING AS SELECT p.[Firstname], p.[Lastname], p.[BirthDay], c.[Description] MaritalStatus FROM [dbo].[Person] p JOIN [dbo].[CodeValue] c ON p.[MaritalStatus] = c.[Value] JOIN [dbo].[CodeNamespace] n ON n.[Id] = c.[CodeNamespaceId] AND n.[Name] = 'MaritalStatus' GO -- Select from View SELECT * FROM [dbo].[Person_v] GO This is excellent write up byMarko Parkkola. Do you have this kind of design setup at your organization? Let us know your opinion. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Database, DBA, Readers Contribution, Software Development, SQL, SQL Authority, SQL Documentation, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Single Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

  - by pinaldave

  In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Single Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Single Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Single Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the single wait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the single wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the single wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• Developer Training – Various Options for Maximum Benefit – Part 4

  - 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 If you have been reading this series, by now you are aware of all the pros and cons that can come along with training.  We’ve asked and answered hard questions, and investigated them “whys” and “hows” of training.  Now it is time to talk about all the different kinds of training that are out there! On Job Training The most common type of training is on the job training.  Everyone receives this kind of education – even experts who come in to consult have to be taught where the printer, pens, and copy machines are.  If you are thinking about more concrete topics, though, on the job training can be some of the easiest to come across.  Picture this: someone in the company whom you really admire is hard at work on a project.  You come up to them and ask to help them out – if they are a busy developer, the odds are that they will say “yes, please!”   If you phrase your question as an offer of help, you can receive training without ever putting someone in the awkward position of acting as a mentor.  However, some people may want the task of being a mentor.  It can never hurt to ask.  Most people will be more than willing to pass their knowledge along. Extreme Programming If your company and coworkers are willing, you can even investigate Extreme Programming.  This is a type of programming that allows small teams to quickly develop code and products that are released with almost immediate user feedback.  You can find more information at http://www.extremeprogramming.org/.  If this is something your company could use, suggest it to your supervisor.  Even if they say no, it will make it clear that you are a go-getter who is interested in new and exciting projects.  If the answer is yes, then you have the opportunity to get some of the best on the job training around. In Person Training Click on Image to Enlarge When you say the word “training,” most people’s minds go back to the classroom, an image they are familiar with.  While training doesn’t always have to be in a traditional setting, because it is so familiar it can also be the most valuable type of training.  There are many ways to get training through a live instructor.  Some companies may be willing to send a representative to you, where employees will get training, sometimes food and coffee, and a live instructor who can answer questions immediately.  Sometimes these trainers are also able to do consultations at the same time, which can invaluable to a company.  If you are the one to asks your supervisor for a training session that can also be turned into a consultation, you may stick in their minds as an incredibly dedicated employee.  If you can’t find a representative, local colleges can also be a good resource for free or cheap classes – or they may have representatives coming who are willing to take on a few more students. Benefits of On Demand Developer Training Of course, you can often get the best of all these types of training with online or On Demand training.  You can get the benefit of a live instructor who is willing to answer questions (although in this case, usually through e-mail or other online venues), there are often real-world examples to follow along – like on the job training – and best of all you can learn whenever you have the time or need.  Did a problem with your server come up at midnight when all your supervisors are safe at home and probably in bed?  No problem!  On Demand training is especially useful if you need to slow down, pause, or rewind a training session.  Not even a real-life instructor can do that! When I was writing this blog post, I felt that each of the subject, which I have covered can be blog posts of itself. However, I wanted to keep the the blog post concise and so touch based on three major training aspects 1) On Job Training 2) In Person Training and 3) Online training. Here is the question for you – is there any other kind of training methods available, which are effective and one should consider it? If yes, what are those, I may write a follow up blog post on the same subject next week. 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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