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• SQLAuthority News – Book Signing Event – SQLPASS 2011 Event Log

  - by pinaldave

  I have been dreaming of writing book for really long time, and I finally got the chance – in fact, two chances!  I recently wrote two books: SQL Programming Joes 2 Pros: Programming and Development for Microsoft SQL Server 2008 [Amazon] | [Flipkart] | [Kindle] and SQL Wait Stats Joes 2 Pros: SQL Performance Tuning Techniques Using Wait Statistics, Types & Queues [Amazon] | [Flipkart] | [Kindle].  I had a lot of fun writing these two books, even though sometimes I had to sacrifice some family time and time for other personal development to write the books. The good side of writing book is that when the efforts put in writing books are recognize by books readers and kind organizations like expressor studio. Book Signing Event Book writing is a complex process.  Even after you spend months, maybe years, writing the material you still have to go through the editing and fact checking processes.  And, once the book is out there, there is no way to take back all the copies to change mistakes or add something you forgot.  Most of the time it is a one-way street. Book Signing Event Just like every author, I had a dream that after the books were written, they would be loved by people and gain acceptance by an audience. My first book, SQL Programming Joes 2 Pros: Programming and Development for Microsoft SQL Server 2008, is extremely popular because it helps lots of people learn various fundamental topics. My second book covers beginning to learn SQL Server Wait Stats, which is a relatively new subject. This book has had very good acceptance in the community. Book Signing Event Helping my community is my primary focus, so I was happy to see this year’s SQLPASS tag line: ‘This is a Community.‘ At the event, the expressor studio guys came up with a very novel idea. They had previously used my books and they had found them very useful. They got 100 copies of the book and decided to give it away to community folks. They invited me and my co-author Rick Morelan to hold a book signing event. We did a book signing on Thursday between 1 pm and 2 pm. Book Signing Event This event was one of the best events for me. This was my first book signing event outside of India. I reached the book signing location around 20 minutes before the scheduled time and what I saw was a big line for the book signing event. I felt very honored looking at the crowd and all the people around the event location. I felt very humbled when I saw some of my very close friends standing in the line to get my signature. It was really heartwarming to see so many enthusiasts waiting for more than an hour to get my signature. While standing in line I had the chance to have a conversation with every single person who showed up for the signature. I made sure that I repeated every single name and wrote it in every book with my signature. There is saying that if we write a name once we will remember it forever. I want to remember all of you who saw me at the book signing. Your comments were wonderful, your feedback was amazing and you were all very supportive. Book Signing Event I have made a note of every conversation I had with all of you when I was signing the books. Once again, I just want to express my thanks for coming to my book signing event. The whole experience was very humbling. On the top of it, I want to thank the expressor studio people who made it possible, who organized the whole signing event. I am so thankful to them for facilitating the whole experience, which is going to be hard to beat by any future experience. My books Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL PASS, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, T SQL, Technology

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• Stretch in multiple components using af:popup, af:region, af:panelTabbed

  - by Arvinder Singh

  Case study: I have a pop-up(dialogue) that contains a region(separate taskflow) showing a tab. The contents of this tab is in a region having a separate taskflow. The jsff page of this taskflow contains a panelSplitter which in turn contains a table. In short the components are : pop-up(dialogue) --> region(separate taskflow) --> tab --> region(separate taskflow) --> panelSplitter --> table At times the tab is not displayed with 100% width or the table in panelSplitter is not 100% visible or the splitter is not visible. Maintaining the stretch for all the components is difficult......not any more!!! Below is the solution that you can make use of in many similar scenarios. I am mentioning the major code snippets affecting the stretch and alignment. pop-up: <af:popup> <af:dialog id="d2" type="none" title="" inlineStyle="width:1200px"> <af:region value="#{bindings.PriceChangePopupFlow1.regionModel}" id="r1"/> </af:dialog> The above region is a jsff containing multiple tabs. I am showing code for a single tab. I kept the tab in a panelStretchLayout. <af:panelStretchLayout id="psl1" topHeight="300px" styleClass="AFStretchWidth"> <af:panelTabbed id="pt1"> <af:showDetailItem text="PO Details" id="sdi1" stretchChildren="first" > <af:region value="#{bindings.PriceChangePurchaseOrderFlow1.regionModel}" id="r1" binding="# {pageFlowScope.priceChangePopupBean.poDetailsRegion}" /> This "region" displays a .jsff containing a table in a panelSplitter. <af:panelSplitter id="ps1"  orientation="horizontal" splitterPosition="700"> <f:facet name="first"> <af:panelHeader text="PurchaseOrder" id="ph1"> <af:table id="md1" rows="#{bindings.PurchaseOrderVO.rangeSize}" That's it!!! We're done... Note the stretchChildren="first" attribute in the af:showDetailItem. That does the trick for us. Oracle docs say the following about stretchChildren :  Valid Values: none, first The stretching behavior for children. Acceptable values include: "none": does not attempt to stretch any children (the default value and the value you need to use if you have more than a single child; also the value you need to use if the child does not support being stretched) "first": stretches the first child (not to be used if you have multiple children as such usage will produce unreliable results; also not to be used if the child does not support being stretched)

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• Introducing Oracle System Assistant

  - by B.Koch

  by Josh Rosen One of the challenges with today's servers is getting the server up and running and understanding what all of the steps are once you plug the server in for the first time. So many different pieces come into play: installing drivers, updating firmware, configuring RAID, and provisioning the operating system. All of these steps must be done before you can even start using the server. Finding the latest firmware and drivers, making sure you have the right versions, and knowing that all the different software and firmware components work together properly can be a real challenge. If not done correctly, such as if you separately downloading disk firmware or controller firmware that doesn't match the existing OS drivers, you could experience bugs, performance problems, and incompatibilities. Gone are the days of having to locate the tools and drivers media that shipped with the server only to find out that newer versions of software and firmware are available on the web. Oracle has solved these challenges in the new X3-2 family of servers by introducing Oracle System Assistant. Oracle System Assistant is an innovative tool that is built-in to every new x86 server. It provides step-by-step assistance with configuring the server, updating firmware and drivers, and provisioning the operating system. Once you have completed all of the steps in the Oracle System Assistant tool, the server is ready to use. Oracle System Assistant was designed to be easy and straightforward. Starting it is as simple as pressing F9 when the server is booting. You'll need a keyboard, monitor, and mouse or you can use the remote console feature of Oracle ILOM (Integrated Lights Out Manager) to access a virtual KVM to the server from any machine. From there Oracle System Assistant will walk you through each of the steps necessary to set up your server. After configuring the network settings for Oracle System Assistant, the next step is to check for any new software or firmware for the server. Oracle System Assistant connects back to Oracle using your My Oracle Support account and downloads any updates that were made available to you for this specific server. This is where you really start to see the innovation that went into Oracle System Assistant. Firmware for Oracle ILOM and BIOS, operating system drivers, and other system firmware (including for option cards and disk drivers) come as a single bundle, downloading as a single unit, that has been engineered and tested to work together by Oracle. Oracle System Assistant figures out the right combination for your server, so you don't have to. Now that the server has the latest firmware, Oracle System Assistant will next walk you through configuring the hardware. From Oracle System Assistant, you can configure many Oracle ILOM settings, including the network settings and initial user accounts. This ensures that ILOM is accessible and ready to use. Oracle System Assistant is where all parts of the server come together. In addition to communicating with Oracle ILOM and interacting with BIOS, Oracle System Assistant understands and can configure the storage subsystem. Before installing the operating system, Oracle System Assistant can detect the storage configuration and configure RAID for all disks in the system. At this point, the server is ready to be provisioned with the host operating system. You can use Oracle System Assistant to provision a supported OS, including Oracle Linux, Oracle VM, RHEL, SuSe Linux, and Windows. And by using Oracle System Assistant, you can be sure that the proper OS drivers are installed for each of the installed hardware components. With Oracle System Assistant, initial setup of the server has never been easier. If we can innovate around problems and find solutions to make our servers easier to manage, this reduces IT costs and makes managing servers simpler. I think with Oracle System Assistant we have done just that. Josh Rosen is a Principal Product Manager at Oracle and previously spent more than a decade as a developer and architect of system management software. Josh has worked on system management for many of Oracle's hardware products ranging from the earliest blade systems to the latest Oracle x86 servers.

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• SQL SERVER – Simple Demo of New Cardinality Estimation Features of SQL Server 2014

  - by Pinal Dave

  SQL Server 2014 has new cardinality estimation logic/algorithm. The cardinality estimation logic is responsible for quality of query plans and majorly responsible for improving performance for any query. This logic was not updated for quite a while, but in the latest version of SQL Server 2104 this logic is re-designed. The new logic now incorporates various assumptions and algorithms of OLTP and warehousing workload. Cardinality estimates are a prediction of the number of rows in the query result. The query optimizer uses these estimates to choose a plan for executing the query. The quality of the query plan has a direct impact on improving query performance. ~ Souce MSDN Let us see a quick example of how cardinality improves performance for a query. I will be using the AdventureWorks database for my example. Before we start with this demonstration, remember that even though you have SQL Server 2014 to see the effect of new cardinality estimates, you will need your database compatibility mode set to 120 which is for SQL Server 2014. If your server instance of SQL Server 2014 but you have set up your database compatibility mode to 110 or any other earlier version, you will get performance from your query like older version of SQL Server. Now we will execute following query in two different compatibility mode and see its performance. (Note that my SQL Server instance is of version 2014). USE AdventureWorks2014 GO -- ------------------------------- -- NEW Cardinality Estimation ALTER DATABASE AdventureWorks2014 SET COMPATIBILITY_LEVEL = 120 GO EXEC [dbo].[uspGetManagerEmployees] 44 GO -- ------------------------------- -- Old Cardinality Estimation ALTER DATABASE AdventureWorks2014 SET COMPATIBILITY_LEVEL = 110 GO EXEC [dbo].[uspGetManagerEmployees] 44 GO Result of Statistics IO Compatibility level 120 Table ‘Person’. Scan count 0, logical reads 6, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table ‘Employee’. Scan count 2, logical reads 7, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table ‘Worktable’. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table ‘Worktable’. Scan count 2, logical reads 7, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Compatibility level 110 Table ‘Worktable’. Scan count 2, logical reads 7, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table ‘Person’. Scan count 0, logical reads 137, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table ‘Employee’. Scan count 2, logical reads 7, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table ‘Worktable’. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. You will notice in the case of compatibility level 110 there 137 logical read from table person where as in the case of compatibility level 120 there are only 6 physical reads from table person. This drastically improves the performance of the query. If we enable execution plan, we can see the same as well. I hope you will find this quick example helpful. You can read more about this in my latest Pluralsight Course. Reference: Pinal Dave (http://blog.SQLAuthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Unit Testing DateTime – The Crazy Way

  - by João Angelo

  We all know that the process of unit testing code that depends on DateTime, particularly the current time provided through the static properties (Now, UtcNow and Today), it’s a PITA. If you go ask how to unit test DateTime.Now on stackoverflow I’ll bet that you’ll get two kind of answers: Encapsulate the current time in your own interface and use a standard mocking framework; Pull out the big guns like Typemock Isolator, JustMock or Microsoft Moles/Fakes and mock the static property directly. Now each alternative has is pros and cons and I would have to say that I glean more to the second approach because the first adds a layer of abstraction just for the sake of testability. However, the second approach depends on commercial tools that not every shop wants to buy or in the not so friendly Microsoft Moles. (Sidenote: Moles is now named Fakes and it will ship with VS 2012) This tends to leave people without an acceptable and simple solution so after reading another of these types of questions in SO I came up with yet another alternative, one based on the first alternative that I presented here but tries really hard to not get in your way with yet another layer of abstraction. So, without further dues, I present you, the Tardis. The Tardis is single section of conditionally compiled code that overrides the meaning of the DateTime expression inside a single class. You still get the normal coding experience of using DateTime all over the place, but in a DEBUG compilation your tests will be able to mock every static method or property of the DateTime class. An example follows, while the full Tardis code can be downloaded from GitHub: using System; using NSubstitute; using NUnit.Framework; using Tardis; public class Example { public Example() : this(string.Empty) { } public Example(string title) { #if DEBUG this.DateTime = DateTimeProvider.Default; this.Initialize(title); } internal IDateTimeProvider DateTime { get; set; } internal Example(string title, IDateTimeProvider provider) { this.DateTime = provider; #endif this.Initialize(title); } private void Initialize(string title) { this.Title = title; this.CreatedAt = DateTime.UtcNow; } private string title; public string Title { get { return this.title; } set { this.title = value; this.UpdatedAt = DateTime.UtcNow; } } public DateTime CreatedAt { get; private set; } public DateTime UpdatedAt { get; private set; } } public class TExample { public void T001() { // Arrange var tardis = Substitute.For<IDateTimeProvider>(); tardis.UtcNow.Returns(new DateTime(2000, 1, 1, 6, 6, 6)); // Act var sut = new Example("Title", tardis); // Assert Assert.That(sut.CreatedAt, Is.EqualTo(tardis.UtcNow)); } public void T002() { // Arrange var tardis = Substitute.For<IDateTimeProvider>(); var sut = new Example("Title", tardis); tardis.UtcNow.Returns(new DateTime(2000, 1, 1, 6, 6, 6)); // Act sut.Title = "Updated"; // Assert Assert.That(sut.UpdatedAt, Is.EqualTo(tardis.UtcNow)); } } This approach is also suitable for other similar classes with commonly used static methods or properties like the ConfigurationManager class.

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• Doing your first mock with JustMock

  - by mehfuzh

  In this post, i will start with a  more traditional mocking example that  includes a fund transfer scenario between two different currency account using JustMock.Our target interface that we will be mocking looks similar to: public interface ICurrencyService {     float GetConversionRate(string fromCurrency, string toCurrency); } Moving forward the SUT or class that will be consuming the  service and will be invoked by user [provided that the ICurrencyService will be passed in a DI style] looks like: public class AccountService : IAccountService         {             private readonly ICurrencyService currencyService;               public AccountService(ICurrencyService currencyService)             {                 this.currencyService = currencyService;             }               #region IAccountService Members               public void TransferFunds(Account from, Account to, float amount)             {                 from.Withdraw(amount);                 float conversionRate = currencyService.GetConversionRate(from.Currency, to.Currency);                 float convertedAmount = amount * conversionRate;                 to.Deposit(convertedAmount);             }               #endregion         }   As, we can see there is a TransferFunds action implemented from IAccountService  takes in a source account from where it withdraws some money and a target account to where the transfer takes place using the provided conversion rate. Our first step is to create the mock. The syntax for creating your instance mocks is pretty much same and  is valid for all interfaces, non-sealed/sealed concrete instance classes. You can pass in additional stuffs like whether its an strict mock or not, by default all the mocks in JustMock are loose, you can use it as default valued objects or stubs as well. ICurrencyService currencyService = Mock.Create<ICurrencyService>(); Using JustMock, setting up your expectations and asserting them always goes with Mock.Arrang|Assert and this is pretty much same syntax no matter what type of mocking you are doing. Therefore,  in the above scenario we want to make sure that the conversion rate always returns 2.20F when converting from GBP to CAD. To do so we need to arrange in the following way: Mock.Arrange(() => currencyService.GetConversionRate("GBP", "CAD")).Returns(2.20f).MustBeCalled(); Here, I have additionally marked the mock call as must. That means it should be invoked anywhere in the code before we do Mock.Assert, we can also assert mocks directly though lamda expressions  but the more general Mock.Assert(mocked) will assert only the setups that are marked as "MustBeCalled()”. Now, coming back to the main topic , as we setup the mock, now its time to act on it. Therefore, first we create our account service class and create our from and to accounts respectively. var accountService = new AccountService(currencyService);   var canadianAccount = new Account(0, "CAD"); var britishAccount = new Account(0, "GBP"); Next, we add some money to the GBP  account: britishAccount.Deposit(100); Finally, we do our transfer by the following: accountService.TransferFunds(britishAccount, canadianAccount, 100); Once, everything is completed, we need to make sure that things were as it is we have expected, so its time for assertions.Here, we first do the general assertions: Assert.Equal(0, britishAccount.Balance); Assert.Equal(220, canadianAccount.Balance); Following, we do our mock assertion,  as have marked the call as “MustBeCalled” it will make sure that our mock is actually invoked. Moreover, we can add filters like how many times our expected mock call has occurred that will be covered in coming posts. Mock.Assert(currencyService); So far, that actually concludes our  first  mock with JustMock and do stay tuned for more. Enjoy!!

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• F# and the rose-tinted reflection

  - by CliveT

  We're already seeing increasing use of many cores on client desktops. It is a change that has been long predicted. It is not just a change in architecture, but our notions of efficiency in a program. No longer can we focus on the asymptotic complexity of an algorithm by counting the steps that a single core processor would take to execute it. Instead we'll soon be more concerned about the scalability of the algorithm and how well we can increase the performance as we increase the number of cores. This may even lead us to throw away our most efficient algorithms, and switch to less efficient algorithms that scale better. We might even be willing to waste cycles in order to speculatively execute at the algorithm rather than the hardware level. State is the big headache in this parallel world. At the hardware level, main memory doesn't necessarily contain the definitive value corresponding to a particular address. An update to a location might still be held in a CPU's local cache and it might be some time before the value gets propagated. To get the latest value, and the notion of "latest" takes a lot of defining in this world of rapidly mutating state, the CPUs may well need to communicate to decide who has the definitive value of a particular address in order to avoid lost updates. At the user program level, this means programmers will need to lock objects before modifying them, or attempt to avoid the overhead of locking by understanding the memory models at a very deep level. I think it's this need to avoid statefulness that has led to the recent resurgence of interest in functional languages. In the 1980s, functional languages started getting traction when research was carried out into how programs in such languages could be auto-parallelised. Sadly, the impracticality of some of the languages, the overheads of communication during this parallel execution, and rapid improvements in compiler technology on stock hardware meant that the functional languages fell by the wayside. The one thing that these languages were good at was getting rid of implicit state, and this single idea seems like a solution to the problems we are going to face in the coming years. Whether these languages will catch on is hard to predict. The mindset for writing a program in a functional language is really very different from the way that object-oriented problem decomposition happens - one has to focus on the verbs instead of the nouns, which takes some getting used to. There are a number of hybrid functional/object languages that have been becoming more popular in recent times. These half-way houses make it easy to use functional ideas for some parts of the program while still allowing access to the underlying object-focused platform without a great deal of impedance mismatch. One example is F# running on the CLR which, in Visual Studio 2010, has because a first class member of the pack. Inside Visual Studio 2010, the tooling for F# has improved to the point where it is easy to set breakpoints and watch values change while debugging at the source level. In my opinion, it is the tooling support that will enable the widespread adoption of functional languages - without this support, people will put off any transition into the functional world for as long as they possibly can. Without tool support it will make it hard to learn these languages. One tool that doesn't currently support F# is Reflector. The idea of decompiling IL to a functional language is daunting, but F# is potentially so important I couldn't dismiss the idea. As I'm currently developing Reflector 6.5, I thought it wise to take four days just to see how far I could get in doing so, even if it achieved little more than to be clearer on how much was possible, and how long it might take. You can read what happened here, and of the insights it gave us on ways to improve the tool.

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• Ongoing confusion about ivars and properties in objective C

  - by Earl Grey

  After almost 8 months being in ios programming, I am again confused about the right approach. Maybe it is not the language but some OOP principle I am confused about. I don't know.. I was trying C# a few years back. There were fields (private variables, private data in an object), there were getters and setters (methods which exposed something to the world) ,and properties which was THE exposed thing. I liked the elegance of the solution, for example there could be a class that would have a property called DailyRevenue...a float...but there was no private variable called dailyRevenue, there was only a field - an array of single transaction revenues...and the getter for DailyRevenue property calculated the revenue transparently. If somehow the internals of daily revenue calculation would change, it would not affect somebody who consumed my DailyRevenue property in any way, since he would be shielded from getter implementation. I understood that sometimes there was , and sometimes there wasn't a 1-1 relationship between fields and properties. depending on the requirements. It seemed ok in my opinion. And that properties are THE way to acces the data in object. I know the difference betweeen private, protected, and public keyword. Now lets get to objectiveC. On what factor should I base my decision about making someting only an ivar or making it as a property? Is the mental model the same as I describe above? I know that ivars are "protected" by default, not "private" asi in c#..But thats ok I think, no big deal for my presnet level of understanding the whole ios development. The point is ivars are not accesible from outside (given i don't make them public..but i won't). The thing that clouds my clear understanding is that I can have IBOutlets from ivars. Why am I seeing internal object data in the UI? *Why is it ok?* On the other hand, if I make an IBOutlet from property, and I do not make it readonly, anybody can change it. Is this ok too? Let's say I have a ParseManager object. This object would use a built in Foundation framework class called NSXMLParser. Obviously my ParseManager will utilize this nsxmlparser's capabilities but will also do some additional work. Now my question is, who should initialize this NSXMLParser object and in which way should I make a reference to it from the ParseManager object, when there is a need to parse something. A) the ParseManager -1) in its default init method (possible here ivar - or - ivar+ppty) -2) with lazyloading in getter (required a ppty here) B) Some other object - who will pass a reference to NSXMLParser object to the ParseManager object. -1) in some custom initializer (initWithParser:(NSXMLPArser *) parser) when creating the ParseManager object.. A1 - the problem is, we create a parser and waste memory while it is not yet needed. However, we can be sure that all methods that are part ot ParserManager object, can use the ivar safely, since it exists. A2 - the problem is, the nsxmlparser is exposed to outside world, although it could be read only. Would we want a parser to be exposed in some scenario? B1 - this could maybe be useful when we would want to use more types of parsers..i dont know... I understand that architectural requirements and and language is not the same. But clearly the two are in relation. How to get out of that mess of my? Please bear with me, I wasn't able to come up with a single ultimate question. And secondly, it's better to not scare me with some superadvanced newspeak that talks about some crazy internals (what the compiler does) and edge cases.

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• SQL SERVER – Basic Calculation and PEMDAS Order of Operation

  - by pinaldave

  After thinking a long time, I have decided to write about this blog post. I had no plan to create a blog post about this subject but the amount of conversation this one has created on my Facebook page, I decided to bring up a few of the question and concerns discussed on the Facebook page. There are more than 10,000 comments here so far. There are lots of discussion about what should be the answer. Well, as far as I can tell there is a big debate going on on Facebook, for educational purpose you should go ahead and read some of the comments. They are very interesting and for sure teach some new stuff. Even though some of the comments are clearly wrong they have made some good points and I believe it for sure develops some logic. Here is my take on this subject. I believe the answer is 9 as I follow PEMDAS  Order of Operation. PEMDAS stands for  parentheses, exponents, multiplication, division, addition, subtraction. PEMDAS is commonly known as BODMAS in India. BODMAS stands for Brackets, Orders (ie Powers and Square Roots, etc), Division, Multiplication,  Addition and Subtraction. PEMDAS and BODMAS are almost same and both of them follow the operation order from LEFT to RIGHT. Let us try to simplify above statement using the PEMDAS or BODMAS (whatever you prefer to call). Step 1: 6 ÷ 2 (1+2) (parentheses first) Step 2: = 6 ÷ 2 * (1+2) (adding multiplication sign for further clarification) Step 3: = 6 ÷ 2* (3) (single digit in parentheses – simplify using operator) Step 4: = 6 ÷ 2 * 3 (Remember next Operation should be LEFT to RIGHT) Step 5: = 3 * 3 (because 6 ÷ 2 = 3; remember LEFT to RIGHT) Step 6: = 9 (final answer) Some often find Step 4 confusing and often ended up multiplying 2 and 3 resulting Step 5 to be 6 ÷ 6, this is incorrect because in this case we did not follow the order of LEFT to RIGHT. When we do not follow the order of operation from LEFT to RIGHT we end up with the answer 1 which is incorrect. Let us see what SQL Server returns as a result. I executed following statement in SQL Server Management Studio SELECT 6/2*(1+2) It is clear that SQL Server also thinks that the answer should be 9. Let us go ahead and ask Google what will be the answer of above question in Google I have searched for the following term: 6/2(1+2) The result also says the answer should be 9. If you want a further reference here is a great video which describes why the answer should be 9 and not 1. And here is a fantastic conversation on Google Groups. Well, now what is your take on this subject? You are welcome to share constructive feedback and your answer may be different from my answer. NOTE: A healthy conversation about this subject is indeed encouraged but if there is a single bad word or comment is flaming it will be deleted without any notification (it does not matter how valuable information it contains). Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Database Mirroring on SQL Server Express Edition

  - by Most Valuable Yak (Rob Volk)

  Like most SQL Server users I'm rather frustrated by Microsoft's insistence on making the really cool features only available in Enterprise Edition.  And it really doesn't help that they changed the licensing for SQL 2012 to be core-based, so now it's like 4 times as expensive!  It almost makes you want to go with Oracle.  That, and a desire to have Larry Ellison do things to your orifices. And since they've introduced Availability Groups, and marked database mirroring as deprecated, you'd think they'd make make mirroring available in all editions.  Alas…they don't…officially anyway.  Thanks to my constant poking around in places I'm not "supposed" to, I've discovered the low-level code that implements database mirroring, and found that it's available in all editions! It turns out that the query processor in all SQL Server editions prepends a simple check before every edition-specific DDL statement: IF CAST(SERVERPROPERTY('Edition') as nvarchar(max)) NOT LIKE '%e%e%e% Edition%' print 'Lame' else print 'Cool' If that statement returns true, it fails. (the print statements are just placeholders)  Go ahead and test it on Standard, Workgroup, and Express editions compared to an Enterprise or Developer edition instance (which support everything). Once again thanks to Argenis Fernandez (b | t) and his awesome sessions on using Sysinternals, I was able to watch the exact process SQL Server performs when setting up a mirror.  Surprisingly, it's not actually implemented in SQL Server!  Some of it is, but that's something of a smokescreen, the real meat of it is simple filesystem primitives. The NTFS filesystem supports links, both hard links and symbolic, so that you can create two entries for the same file in different directories and/or different names.  You can create them using the MKLINK command in a command prompt: mklink /D D:\SkyDrive\Data D:\Data mklink /D D:\SkyDrive\Log D:\Log This creates a symbolic link from my data and log folders to my Skydrive folder.  Any file saved in either location will instantly appear in the other.  And since my Skydrive will be automatically synchronized with the cloud, any changes I make will be copied instantly (depending on my internet bandwidth of course). So what does this have to do with database mirroring?  Well, it seems that the mirroring endpoint that you have to create between mirror and principal servers is really nothing more than a Skydrive link.  Although it doesn't actually use Skydrive, it performs the same function.  So in effect, the following statement: ALTER DATABASE Mir SET PARTNER='TCP://MyOtherServer.domain.com:5022' Is turned into: mklink /D "D:\Data" "\\MyOtherServer.domain.com\5022$" The 5022$ "port" is actually a hidden system directory on the principal and mirror servers. I haven't quite figured out how the log files are included in this, or why you have to SET PARTNER on both principal and mirror servers, except maybe that mklink has to do something special when linking across servers.  I couldn't get the above statement to work correctly, but found that doing mklink to a local Skydrive folder gave me similar functionality. To wrap this up, all you have to do is the following: Install Skydrive on both SQL Servers (principal and mirror) and set the local Skydrive folder (D:\SkyDrive in these examples) On the principal server, run mklink /D on the data and log folders to point to SkyDrive: mklink /D D:\SkyDrive\Data D:\Data On the mirror server, run the complementary linking: mklink /D D:\Data D:\SkyDrive\Data Create your database and make sure the files map to the principal data and log folders (D:\Data and D:\Log) Viola! Your databases are kept in sync on multiple servers! One wrinkle you will encounter is that the mirror server will show the data and log files, but you won't be able to attach them to the mirror SQL instance while they are attached to the principal. I think this is a bug in the Skydrive, but as it turns out that's fine: you can't access a mirror while it's hosted on the principal either.  So you don't quite get automatic failover, but you can attach the files to the mirror if the principal goes offline.  It's also not exactly synchronous, but it's better than nothing, and easier than either replication or log shipping with a lot less latency. I will end this with the obvious "not supported by Microsoft" and "Don't do this in production without an updated resume" spiel that you should by now assume with every one of my blog posts, especially considering the date.

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• Windows Workflow Foundation (WF) and things I were more intuitive

  - by pjohnson

  I've started using Windows Workflow Foundation, and so far ran into a few things that aren't incredibly obvious. Microsoft did a good job of providing a ton of samples, which is handy because you need them to get anywhere with WF. The docs are thin, so I've been bouncing between samples and downloadable labs to figure out how to implement various activities in a workflow. Code separation or not? You can create a workflow and activity in Visual Studio with or without code separation, i.e. just a .cs "Component" style object with a Designer.cs file, or a .xoml XML markup file with code behind (beside?) it. Absence any obvious advantage to one or the other, I used code separation for workflows and any complex custom activities, and without code separation for custom activities that just inherit from the Activity class and thus don't have anything special in the designer. So far, so good. Service - In the WF world, this is simply a class that talks to the workflow about things outside the workflow, not to be confused with how the term "service" is used in every other context I've seen in the Windows and .NET world, i.e. an executable that waits for events or requests from a client and services them (Windows service, web service, WCF service, etc.). ListenActivity - Such a great concept, yet so unintuitive. It seems you need at least two branches (EventDrivenActivity instances), one for your positive condition and one for a timeout. The positive condition has a HandleExternalEventActivity, and the timeout has a DelayActivity followed by however you want to handle the delay, e.g. a ThrowActivity. The timeout is simple enough; wiring up the HandleExternalEventActivity is where things get fun. You need to create a service (see above), and an interface for that service (this seems more complex than should be necessary--why not have activities just wire to a service directly?). And you need to create a custom EventArgs class that inherits from ExternalDataEventArgs--you can't create an ExternalDataEventArgs event handler directly, even if you don't need to add any more information to the event args, despite ExternalDataEventArgs not being marked as an abstract class, nor a compiler error nor warning nor any other indication that you're doing something wrong, until you run it and find that it always times out and get to check every place mentioned here to see why. Your interface and service need an event that consumes your custom EventArgs class, and a method to fire that event. You need to call that method from somewhere. Then you get to hope that you did everything just right, or that you can step through code in the debugger before your Delay timeout expires. Yes, it's as much fun as it sounds. TransactionScopeActivity - I had the bright idea of putting one in as a placeholder, then filling in the database updates later. That caused this error: The workflow hosting environment does not have a persistence service as required by an operation on the workflow instance "[GUID]". ...which is about as helpful as "Object reference not set to an instance of an object" and even more fun to debug. Google led me to this Microsoft Forums hit, and from there I figured out it didn't like that the activity had no children. Again, a Validator on TransactionScopeActivity would have pointed this out to me at design time, rather than handing me a nearly useless error at runtime. Easily enough, I disabled the activity and that fixed it. I still see huge potential in my work where WF could make things easier and more flexible, but there are some seriously rough edges at the moment. Maybe I'm just spoiled by how much easier and more intuitive development elsewhere in the .NET Framework is.

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• Project structure: where to put business logic

  - by Mister Smith

  First of all, I'm not asking where does business logic belong. This has been asked before and most answers I've read agree in that it belongs in the model: Where to put business logic in MVC design? How much business logic should be allowed to exist in the controller layer? How accurate is "Business logic should be in a service, not in a model"? Why put the business logic in the model? What happens when I have multiple types of storage? However people disagree in the way this logic should be distributed across classes. There seem to exist three major currents of thought: Fat model with business logic inside entity classes. Anemic model and business logic in "Service" classes. It depends. I find all of them problematic. The first option is what most Fowlerites stick to. The problem with a fat model is that sometimes a business logic funtion is not only related to a class, and instead uses a bunch of other classes. If, for example, we are developing a web store, there should be a function that calcs an order's total. We could think of putting this function inside the Order class, but what actually happens is that the logic needs to use different classes, not only data contained in the Order class, but also in the User class, the Session class, and maybe the Tax class, Country class, or Giftcard, Payment, etc. Some of these classes could be composed inside the Order class, but some others not. Sorry if the example is not very good, but I hope you understand what I mean. Putting such a function inside the Order class would break the single responsibility principle, adding unnecesary dependences. The business logic would be scattered across entity classes, making it hard to find. The second option is the one I usually follow, but after many projects I'm still in doubt about how to name the class or classes holding the business logic. In my company we usually develop apps with offline capabilities. The user is able to perform entire transactions offline, so all validation and business rules should be implemented in the client, and then there's usually a background thread that syncs with the server. So we usually have the following classes/packages in every project: Data model (DTOs) Data Access Layer (Persistence) Web Services layer (Usually one class per WS, and one method per WS method). Now for the business logic, what is the standard approach? A single class holding all the logic? Multiple classes? (if so, what criteria is used to distribute the logic across them?). And how should we name them? FooManager? FooService? (I know the last one is common, but in our case it is bad naming because the WS layer usually has classes named FooWebService). The third option is probably the right one, but it is also devoid of any useful info. To sum up: I don't like the first approach, but I accept that I might have been unable to fully understand the Zen of it. So if you advocate for fat models as the only and universal solution you are welcome to post links explaining how to do it the right way. I'd like to know what is the standard design and naming conventions for the second approach in OO languages. Class names and package structure, in particular. It would also be helpful too if you could include links to Open Source projects showing how it is done. Thanks in advance.

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• Big Data – Beginning Big Data Series Next Month in 21 Parts

  - by Pinal Dave

  Big Data is the next big thing. There was a time when we used to talk in terms of MB and GB of the data. However, the industry is changing and we are now moving to a conversation where we discuss about data in Petabyte, Exabyte and Zettabyte. It seems that the world is now talking about increased Volume of the data. In simple world we all think that Big Data is nothing but plenty of volume. In reality Big Data is much more than just a huge volume of the data. When talking about the data we need to understand about variety and volume along with volume. Though Big data look like a simple concept, it is extremely complex subject when we attempt to start learning the same. My Journey I have recently presented on Big Data in quite a few organizations and I have received quite a few questions during this roadshow event. I have collected all the questions which I have received and decided to post about them on the blog. In the month of October 2013, on every weekday we will be learning something new about Big Data. Every day I will share a concept/question and in the same blog post we will learn the answer of the same. Big Data – Plenty of Questions I received quite a few questions during my road trip. Here are few of the questions. I want to learn Big Data – where should I start? Do I need to know SQL to learn Big Data? What is Hadoop? There are so many organizations talking about Big Data, and every one has a different approach. How to start with big Data? Do I need to know Java to learn about Big Data? What is different between various NoSQL languages. I will attempt to answer most of the questions during the month long series in the next month. Big Data – Big Subject Big Data is a very big subject and I no way claim that I will be covering every single big data concept in this series. However, I promise that I will be indeed sharing lots of basic concepts which are revolving around Big Data. We will discuss from fundamentals about Big Data and continue further learning about it. I will attempt to cover the concept so simple that many of you might have wondered about it but afraid to ask. Your Role! During this series next month, I need your one help. Please keep on posting questions you might have related to big data as blog post comments and on Facebook Page. I will monitor them closely and will try to answer them as well during this series. Now make sure that you do not miss any single blog post in this series as every blog post will be linked to each other. You can subscribe to my feed or like my Facebook page or subscribe via email (by entering email in the blog post). Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Big Data, PostADay, SQL, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Integrating with Fusion Applications using SOAP web services and REST APIs (Part 1 of 2) by Arvind Srinivasamoorthy

  - by JuergenKress

  Fusion Applications provides several types of interfaces to facilitate integration with other applications within the enterprise and on the cloud.As one of the key integration interfaces, Fusion Applications (FA) supports SOAP services based integration, both inbound and outbound. At this point FA doesn’t provide REST API’s but it is planned for a future release. It is however possible to invoke external REST APIs from FA which we will discuss. Oracle continues to invest in improving both SOAP and REST based connectivity. The content in this blog is based on features that were available at the time of writing it. In this two part blog, I will cover the following topics briefly. Invoking FA SOAP web services from external applications Identifying the FA SOAP web service to be invoked Sample invocation from an external application Techniques to invoke FA services from an ADF application Invoking external SOAP Web Services from FA (covered in Part 2) Invoking external REST APIs from FA (covered in Part 2) I’ll touch upon some basics, so that you can quickly build a few SOAP/REST interactions with FA. If you do not already have access to an FA instance (on-premise or SaaS), you can request for a free 30 day trial of the Oracle Sales Cloud using http://cloud.oracle.com 1. Invoking FA SOAP web services from external applications There are two main types of services that FA exposes -  ADF Services - These services allow you to perform CRUD operations on Fusion business objects. For example, Sales Party Service, Opportunity Service etc. Using these services you can typically perform operations such as get, find, create, delete, update etc on FA objects.These services are typically useful for UI driven integrations such as looking up FA information from external application UIs, using third party Interfaces to create/update data in FA. They are also used in non-UI driven integration uses cases such as initial upload of business or setup data, synchronizing data with an external systems, etc. - Composite Services – These services involve more logic than CRUD and often involving human workflows, rules etc. These services perform a business function such as Get Orchestration Order Service and are used when building larger process based integrations with external systems.These services are usually asynchronous in nature and are not typically used for UI integration patterns. 1a. Identifying the FA SOAP web service to be invoked All FA web service metadata is available through an OER instance (Oracle Enterprise Repository) which is publicly available via http://fusionappsoer.oracle.com. This is the starting point for you to discover the services that you are going to work with. You do not need to own a FA account to browse the services using the above UI You can use the search area on the left to narrow down your search to what you are looking for. For example, you can choose the type as by ADF Services or Composite, you can narrow your search to a specific FA version, Product Family etc. Read the complete article here. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Technorati Tags: AppAdvantage,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress,Arvind Srinivasamoorthy

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• 256 Worker Role 3D Rendering Demo is now a Lab on my Azure Course

  - by Alan Smith

  Ever since I came up with the crazy idea of creating an Azure application that would spin up 256 worker roles (please vote if you like it ) to render a 3D animation created using the Kinect depth camera I have been trying to think of something useful to do with it. I have also been busy working on developing training materials for a Windows Azure course that I will be delivering through a training partner in Stockholm, and for customers wanting to learn Windows Azure. I hit on the idea of combining the render demo and a course lab and creating a lab where the students would create and deploy their own mini render farms, which would participate in a single render job, consisting of 2,000 frames. The architecture of the solution is shown below. As students would be creating and deploying their own applications, I thought it would be fun to introduce some competitiveness into the lab. In the 256 worker role demo I capture the rendering statistics for each role, so it was fairly simple to include the students name in these statistics. This allowed the process monitor application to capture the number of frames each student had rendered and display a high-score table. When I demoed the application I deployed one instance that started rendering a frame every few minutes, and the challenge for the students was to deploy and scale their applications, and then overtake my single role instance by the end of the lab time. I had the process monitor running on the projector during the lab so the class could see the progress of their deployments, and how they were performing against my implementation and their classmates. When I tested the lab for the first time in Oslo last week it was a great success, the students were keen to be the first to build and deploy their solution and then watch the frames appear. As the students mostly had MSDN suspicions they were able to scale to the full 20 worker role instances and before long we had over 100 worker roles working on the animation. There were, however, a few issues who the couple of issues caused by the competitive nature of the lab. The first student to scale the application to 20 instances would render the most frames and win; there was no way for others to catch up. Also, as they were competing against each other, there was no incentive to help others on the course get their application up and running. I have now re-written the lab to divide the student into teams that will compete to render the most frames. This means that if one developer on the team can deploy and scale quickly, the other team still has a chance to catch up. It also means that if a student finishes quickly and puts their team in the lead they will have an incentive to help the other developers on their team get up and running. As I was using “Sharks with Lasers” for a lot of my demos, and reserved the sharkswithfreakinlasers namespaces for some of the Azure services (well somebody had to do it), the students came up with some creative alternatives, like “Camels with Cannons” and “Honey Badgers with Homing Missiles”. That gave me the idea for the teams having to choose a creative name involving animals and weapons. The team rendering architecture diagram is shown below.   Render Challenge Rules In order to ensure fair play a number of rules are imposed on the lab. ·         The class will be divided into teams, each team choses a name. ·         The team name must consist of a ferocious animal combined with a hazardous weapon. ·         Teams can allocate as many worker roles as they can muster to the render job. ·         Frame processing statistics and rendered frames will be vigilantly monitored; any cheating, tampering, and other foul play will result in penalties. The screenshot below shows an example of the team render farm in action, Badgers with Bombs have taken a lead over Camels with Cannons, and both are  leaving the Sharks with Lasers standing. If you are interested in attending a scheduled delivery of my Windows Azure or Windows Azure Service bus courses, or would like on-site training, more details are here.

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• Using GMail's SMTP and IMAP servers in Notification Mailer

  - by Saroja Kandepuneni

  Overview GMail offers free, reliable, popular SMTP and IMAP services, because of which many people are interested to use it. GMail can be used when there are no in-house SMTP/IMAP servers for testing or debugging purposes. This blog explains how to install GMail SSL certificate in Concurrent Tier, testing the connection using a standalone program, running Mailer diagnostics and configuring GMail IMAP and SMTP servers for Workflow Notification Mailer Inbound and Outbound connections. GMail servers configuration SMTP server Host Name  smtp.gmail.com SSL Port  465 TLS/SSL required  Yes User Name  Your full email address (including @gmail.com or @your_domain.com) Password  Your gmail passwor  IMAP server  Host Name imap.gmail.com  SSL Port 993 TLS/SSL Required Yes  User Name  Your full email address (including @gmail.com or @your_domain.com)  Password Your gmail password GMail SSL Certificate Installation The following is the procedure to install the GMail SSL certificate Copy the below GMail SSL certificate to a file eg: gmail.cer -----BEGIN CERTIFICATE-----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-----END CERTIFICATE----- Install the SSL certificate into the default JRE location or any other location using below command Installing into a dfeault JRE location in EBS instance         # keytool -import -trustcacerts -keystore $AF_JRE_TOP/lib/security/cacerts  -storepass changeit -alias gmail-lnx_chainnedcert -file gmail.cer Install into a custom location         # keytool -import -trustcacerts -keystore <customLocation>  -storepass changeit -alias gmail-lnx_chainnedcert -file gmail.cer       <customLocation> -- directory in instance where the certificate need to be installed After running the above command you can see the following response         Trust this certificate? [no]:  yes        Certificate was added to keystore Running Mailer Command Line Diagnostics Run Mailer command line diagnostics from conccurrent tier where Mailer is running, to check the IMAP connection using the below command $AFJVAPRG -classpath $AF_CLASSPATH -Dprotocol=imap -Ddbcfile=$FND_SECURE/$TWO_TASK.dbc -Dserver=imap.gmail.com -Dport=993 -Dssl=Y -Dtruststore=$AF_JRE_TOP/lib/security/cacerts -Daccount=<gmail username> -Dpassword=<password> -Dconnect_timeout=120 -Ddebug=Y -Dlogfile=GmailImapTest.log -DdebugMailSession=Y oracle.apps.fnd.wf.mailer.Mailer Run Mailer command line diagnostics from concurrent tier where Mailer is running, to check the SMTP connection using the below command   $AFJVAPRG -classpath $AF_CLASSPATH -Dprotocol=smtp -Ddbcfile=$FND_SECURE/$TWO_TASK.dbc -Dserver=smtp.gmail.com -Dport=465 -Dssl=Y -Dtruststore=$AF_JRE_TOP/lib/security/cacerts -Daccount=<gmail username> -Dpassword=<password> -Dconnect_timeout=120 -Ddebug=Y -Dlogfile=GmailSmtpTest.log -DdebugMailSession=Y oracle.apps.fnd.wf.mailer.Mailer Standalone program to verify the IMAP connection Run the below standalone program from the concurrent tier node where Mailer is running to verify the connection with GMail IMAP server. It connects to the Gmail IMAP server with the given GMail user name and password and lists all the folders that exist in that account. If the Gmail IMAP server is not working for the  Mailer check whether the PROCESSED and DISCARD folders exist for the GMail account, if not create manually by logging into GMail account.Sample program to test GMail IMAP connection  The standalone program can be run as below  $java GmailIMAPTest GmailUsername GMailUserPassword            Standalone program to verify the SMTP connection Run the below standalone program from the concurrent tier node where Mailer is running to verify the connection with GMail SMTP server. It connects to the GMail SMTP server by authenticating with the given user name and password  and sends a test email message to the give recipient user email address. Sample program to test GMail SMTP connection The standalone program can be run as below  $java GmailSMTPTest GmailUsername gMailPassword recipientEmailAddress    Warnings As gmail.com is an external domain, the Mailer concurrent tier should allow the connection with GMail server Please keep in mind when using it for corporate facilities, that the e-mail data would be stored outside the corporate network

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• Best Design Pattern for Coupling User Interface Components and Data Structures

  - by szahn

  I have a windows desktop application with a tree view. Due to lack of a sound data-binding solution for a tree view, I've implemented my own layer of abstraction on it to bind nodes to my own data structure. The requirements are as follows: Populate a tree view with nodes that resemble fields in a data structure. When a node is clicked, display the appropriate control to modify the value of that property in the instance of the data structure. The tree view is populated with instances of custom TreeNode classes that inherit from TreeNode. The responsibility of each custom TreeNode class is to (1) format the node text to represent the name and value of the associated field in my data structure, (2) return the control used to modify the property value, (3) get the value of the field in the control (3) set the field's value from the control. My custom TreeNode implementation has a property called "Control" which retrieves the proper custom control in the form of the base control. The control instance is stored in the custom node and instantiated upon first retrieval. So each, custom node has an associated custom control which extends a base abstract control class. Example TreeNode implementation: //The Tree Node Base Class public abstract class TreeViewNodeBase : TreeNode { public abstract CustomControlBase Control { get; } public TreeViewNodeBase(ExtractionField field) { UpdateControl(field); } public virtual void UpdateControl(ExtractionField field) { Control.UpdateControl(field); UpdateCaption(FormatValueForCaption()); } public virtual void SaveChanges(ExtractionField field) { Control.SaveChanges(field); UpdateCaption(FormatValueForCaption()); } public virtual string FormatValueForCaption() { return Control.FormatValueForCaption(); } public virtual void UpdateCaption(string newValue) { this.Text = Caption; this.LongText = newValue; } } //The tree node implementation class public class ExtractionTypeNode : TreeViewNodeBase { private CustomDropDownControl control; public override CustomControlBase Control { get { if (control == null) { control = new CustomDropDownControl(); control.label1.Text = Caption; control.comboBox1.Items.Clear(); control.comboBox1.Items.AddRange( Enum.GetNames( typeof(ExtractionField.ExtractionType))); } return control; } } public ExtractionTypeNode(ExtractionField field) : base(field) { } } //The custom control base class public abstract class CustomControlBase : UserControl { public abstract void UpdateControl(ExtractionField field); public abstract void SaveChanges(ExtractionField field); public abstract string FormatValueForCaption(); } //The custom control generic implementation (view) public partial class CustomDropDownControl : CustomControlBase { public CustomDropDownControl() { InitializeComponent(); } public override void UpdateControl(ExtractionField field) { //Nothing to do here } public override void SaveChanges(ExtractionField field) { //Nothing to do here } public override string FormatValueForCaption() { //Nothing to do here return string.Empty; } } //The custom control specific implementation public class FieldExtractionTypeControl : CustomDropDownControl { public override void UpdateControl(ExtractionField field) { comboBox1.SelectedIndex = comboBox1.FindStringExact(field.Extraction.ToString()); } public override void SaveChanges(ExtractionField field) { field.Extraction = (ExtractionField.ExtractionType) Enum.Parse(typeof(ExtractionField.ExtractionType), comboBox1.SelectedItem.ToString()); } public override string FormatValueForCaption() { return string.Empty; } The problem is that I have "generic" controls which inherit from CustomControlBase. These are just "views" with no logic. Then I have specific controls that inherit from the generic controls. I don't have any functions or business logic in the generic controls because the specific controls should govern how data is associated with the data structure. What is the best design pattern for this?

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• Do your filesystems have un-owned files ?

  - by darrenm

  As part of our work for integrated compliance reporting in Solaris we plan to provide a check for determining if the system has "un-owned files", ie those which are owned by a uid that does not exist in our configured nameservice.  Tests such as this already exist in the Solaris CIS Benchmark (9.24 Find Un-owned Files and Directories) and other security benchmarks. The obvious method of doing this would be using find(1) with the -nouser flag.  However that requires we bring into memory the metadata for every single file and directory in every local file system we have mounted.  That is probaby not an acceptable thing to do on a production system that has a large amount of storage and it is potentially going to take a long time. Just as I went to bed last night an idea for a much faster way of listing file systems that have un-owned files came to me. I've now implemented it and I'm happy to report it works very well and peforms many orders of magnatude better than using find(1) ever will.   ZFS (since pool version 15) has per user space accounting and quotas.  We can report very quickly and without actually reading any files at all how much space any given user id is using on a ZFS filesystem.  Using that information we can implement a check to very quickly list which filesystems contain un-owned files. First a few caveats because the output data won't be exactly the same as what you get with find but it answers the same basic question.  This only works for ZFS and it will only tell you which filesystems have files owned by unknown users not the actual files.  If you really want to know what the files are (ie to give them an owner) you still have to run find(1).  However it has the huge advantage that it doesn't use find(1) so it won't be dragging the metadata for every single file and directory on the system into memory. It also has the advantage that it can check filesystems that are not mounted currently (which find(1) can't do). It ran in about 4 seconds on a system with 300 ZFS datasets from 2 pools totalling about 3.2T of allocated space, and that includes the uid lookups and output. #!/bin/sh for fs in $(zfs list -H -o name -t filesystem -r rpool) ; do unknowns="" for uid in $(zfs userspace -Hipn -o name,used $fs | cut -f1); do if [ -z "$(getent passwd $uid)" ]; then unknowns="$unknowns$uid " fi done if [ ! -z "$unknowns" ]; then mountpoint=$(zfs list -H -o mountpoint $fs) mounted=$(zfs list -H -o mounted $fs) echo "ZFS File system $fs mounted ($mounted) on $mountpoint \c" echo "has files owned by unknown user ids: $unknowns"; fi done Sample output: ZFS File system rpool/ROOT/solaris-30/var mounted (no) on /var has files owned by unknown user ids: 6435 33667 101 ZFS File system rpool/ROOT/solaris-32/var mounted (yes) on /var has files owned by unknown user ids: 6435 33667ZFS File system builds/bob mounted (yes) on /builds/bob has files owned by unknown user ids: 101 Note that the above might not actually appear exactly like that in any future Solaris product or feature, it is provided just as an example of what you can do with ZFS user space accounting to answer questions like the above.

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• How do I get sound output on HDMI without the need to start X?

  - by Magnus Hoff

  I have a headless machine connected to my sound system, and I am using it to run a music playing daemon that I control over the network. (Among other things) However, I can't seem to be able to have sound come out of my speakers without running X. I am running pulse audio in a system wide instance and my daemon is not running within X. Nevertheless, when my daemon is playing music without me hearing it, I can fix it by running startx in an unrelated session. After X starts, I can hear the sound. The sound disappears again if I kill the X server. Interestingly/annoyingly, the sound also stops after X has been running for a few minutes. This could possibly be because of a screen saver of some sort, but I haven't been able to verify or falsify this theory. So my current workaround is to ssh into the box whenever I want music and startx, and restart it every fifteen minutes or so. I'd like to do better. I have been able to verify the following: Adjustments in alsamixer have no effect on this problem. The relevant output channel is never muted In alsamixer, I can see no difference between when the sound is working and when it isn't Nothing is muted in pactl list There is no difference in the output from pactl list between before starting X and after it's started. (Except the identifier of the pactl instance connected to pulse, which is different each time you run pactl) The user running the music daemon is a member of the groups audio, pulse and pulse-access The music daemon program does not report any error messages and acts as if it is playing the music like it should Some form of dbus daemon is running. ps aux|grep dbus reports dbus-daemon --system --fork --activation=upstart before and after I have started X Some details about my hardware: Motherboard: http://www.asus.com/Motherboards/AT5IONTI_DELUXE/ Sound chip: Nvidia GPU 0b HDMI/DP (from alsamixer) Using HDMI for output (Machine also has an Intel Realtek ALC887 that I am not using) Output of lsmod: Module Size Used by deflate 12617 0 zlib_deflate 27139 1 deflate ctr 13201 0 twofish_generic 16635 0 twofish_x86_64_3way 25287 0 twofish_x86_64 12907 1 twofish_x86_64_3way twofish_common 20919 3 twofish_generic,twofish_x86_64_3way,twofish_x86_64 camellia 29348 0 serpent 29125 0 blowfish_generic 12530 0 blowfish_x86_64 21466 0 blowfish_common 16739 2 blowfish_generic,blowfish_x86_64 cast5 25112 0 des_generic 21415 0 xcbc 12815 0 rmd160 16744 0 bnep 18281 2 rfcomm 47604 12 sha512_generic 12796 0 crypto_null 12918 0 parport_pc 32866 0 af_key 36389 0 ppdev 17113 0 binfmt_misc 17540 1 nfsd 281980 2 ext2 73795 1 nfs 436929 1 lockd 90326 2 nfsd,nfs fscache 61529 1 nfs auth_rpcgss 53380 2 nfsd,nfs nfs_acl 12883 2 nfsd,nfs sunrpc 255224 16 nfsd,nfs,lockd,auth_rpcgss,nfs_acl btusb 18332 2 vesafb 13844 2 pl2303 17957 1 ath3k 12961 0 bluetooth 180153 24 bnep,rfcomm,btusb,ath3k snd_hda_codec_hdmi 32474 4 nvidia 11308613 0 ftdi_sio 40679 1 usbserial 47113 6 pl2303,ftdi_sio psmouse 97485 0 snd_hda_codec_realtek 224173 1 snd_hda_intel 33719 5 snd_hda_codec 127706 3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel serio_raw 13211 0 snd_seq_midi 13324 0 snd_hwdep 17764 1 snd_hda_codec snd_pcm 97275 3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec snd_rawmidi 30748 1 snd_seq_midi snd_seq_midi_event 14899 1 snd_seq_midi snd_seq 61929 2 snd_seq_midi,snd_seq_midi_event snd_timer 29990 2 snd_pcm,snd_seq snd_seq_device 14540 3 snd_seq_midi,snd_rawmidi,snd_seq snd 79041 20 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device asus_atk0110 18078 0 mac_hid 13253 0 jc42 13948 0 soundcore 15091 1 snd snd_page_alloc 18529 2 snd_hda_intel,snd_pcm coretemp 13554 0 i2c_i801 17570 0 lp 17799 0 parport 46562 3 parport_pc,ppdev,lp r8169 62154 0 Any ideas? What does X do that's so important?

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• Reduce ERP Consolidation Risks with Oracle Master Data Management

  - by Dain C. Hansen

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Reducing the Risk of ERP Consolidation starts first and foremost with your Data.This is nothing new; companies with multiple misaligned ERP systems are often putting inordinate risk on their business. It can translate to too much inventory, long lead times, and shipping issues from poorly organized and specified goods. And don’t forget the finance side! When goods are shipped and promises are kept/not kept there’s the issue of accounts. No single chart of counts translates to no accountability. So – I’ve decided. I need to consolidate! Well, you can’t consolidate ERP applications [for that matter any of your applications] without first considering your data. This means looking at how your data is being integrated by these ERP systems, how it is being synchronized, what information is being shared, or not being shared. Most importantly, making sure that the data is mastered. What is the best way to do this? In the recent webcast: Reduce ERP consolidation Risks with Oracle Master Data Management we outlined 3 key guidelines: #1: Consolidate your Product Data#2: Consolidate your Customer, Supplier (Party Data) #3: Consolidate your Financial Data Together these help customers achieve reduced risk, better customer intimacy, reducing inventory levels, elimination of product variations, and finally a single master chart of accounts. In the case of Oracle's customer Zebra Technologies, they were able to consolidate over 140 applications by mastering their data. Ultimately this gave them 60% cost savings for the year on IT spend. Oracle’s Solution for ERP Consolidation: Master Data Management Oracle's enterprise master data management (MDM) can play a big role in ERP consolidation. It includes a set of products that consolidates and maintains complete, accurate, and authoritative master data across the enterprise and distributes this master information to all operational and analytical applications as a shared service. It’s optimized to work with any application source (not just Oracle’s) and can integrate using technology from Oracle Fusion Middleware (i.e. GoldenGate for data synchronization and real-time replication or ODI with its E-LT optimized bulk data and transformation capability). In addition especially for ERP consolidation use cases it’s important to leverage the AIA and SOA capabilities as part of Fusion Middleware to connect these multiple applications together and relay the data into the correct hub. Oracle’s MDM strategy is a unique offering in the industry, one that has common elements across the top and bottom in Middleware, BI/DW, Engineered systems combined with Enterprise Data Quality to enable comprehensive Data Governance at all levels. In addition, Oracle MDM provides the best-in-class capabilities to master all variations of data, including customer, supplier, product, financial data. But ultimately at the center of Oracle MDM is your data, making it more trusted, making it secure and accessible as part of a role-based approach, and getting it to make sense to you in any situation, whether it’s a specific ERP process like we talked about or something that is custom to your organization. To learn more about these techniques in ERP consolidation watch our webcast or goto our Oracle MDM website at www.oracle.com/goto/mdm

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• A tiny Utility to recycle an IIS Application Pool

  - by Rick Strahl

  In the last few weeks I've annoyingly been having problems with an area on my Web site. It's basically ancient articles that are using ASP classic pages and for reasons unknown ASP classic locks up on these pages frequently. It's not an individual page, but ALL ASP classic pages lock up. Ah yes, gotta old tech gone bad. It's not super critical since the content is really old, but still a hassle since it's linked content that still gets quite a bit of traffic. When it happens all ASP classic in that AppPool dies. I've been having a hard time tracking this one down - I suspect an errant COM object I have a Web Monitor running on the server that's checking for failures and while the monitor can detect the failures when the timeouts occur, I didn't have a good way to just restart that particular application pool. I started putzing around with PowerShell, but - as so often seems the case - I can never get the PowerShell syntax right - I just don't use it enough and have to dig out cheat sheets etc. In any case, after about 20 minutes of that I decided to just create a small .NET Console Application that does the trick instead, and in a few minutes I had this:using System; using System.Collections.Generic; using System.Text; using System.DirectoryServices; namespace RecycleApplicationPool { class Program { static void Main(string[] args) { string appPoolName = "DefaultAppPool"; string machineName = "LOCALHOST"; if (args.Length > 0) appPoolName = args[0]; if (args.Length > 1) machineName = args[1]; string error = null; DirectoryEntry root = null; try { Console.WriteLine("Restarting Application Pool " + appPoolName + " on " + machineName + "..."); root = new DirectoryEntry("IIS://" + machineName + "/W3SVC/AppPools/" +appPoolName); Console.WriteLine(root.InvokeGet("Name")); root.Invoke("Recycle"); Console.WriteLine("Application Pool recycling complete..."); } catch(Exception ex) { error = "Error: Unable to access AppPool: " + ex.Message; } if ( !string.IsNullOrEmpty(error) ) { Console.WriteLine(error); return; } } } } To run in you basically provide the name of the ApplicationPool and optionally a machine name if it's not on the local box. RecyleApplicationPool.exe "WestWindArticles" And off it goes. What's nice about AppPool recycling versus doing a full IISRESET is that it only affects the AppPool, and more importantly AppPool recycles happen in a staggered fashion - the existing instance isn't shut down immediately until requests finish while a new instance is fired up to handle new requests. So, now I can easily plug this Executable into my West Wind Web Monitor as an action to take when the site is not responding or timing out which is a big improvement than hanging for an unspecified amount of time. I'm posting this fairly trivial bit of code just in case somebody (maybe myself a few months down the road) is searching for ApplicationPool recyling code. It's clearly trivial, but I've written batch files for this a bunch of times before and actually having a small utility around without having to worry whether Powershell is installed and configured right is actually an improvement. Next time I think about using PowerShell remind me that it's just easier to just build a small .NET Console app, 'k? :-) Resources Download Executable and VS Project© Rick Strahl, West Wind Technologies, 2005-2012Posted in IIS7  .NET  Windows   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Windows Phone 8, possible tablets and what the latest update might mean

  - by Roger Hart

  Microsoft have just announced an update to Windows Phone 8. As one of the five, maybe six people who actually bought a WP8 handset I found this interesting. Then I read the blog post about it, and rushed off to write somewhat less than a thousand words about a single picture. The blog post announces an extra column of tiles on the start screen, and support for higher resolutions. If we ignore all the usual flummery about how this will make your life better, that (and the rotation lock) sounds a little like stage setting for tablets. Looking at the preview screenshot, I started to wonder. What it’s called Phablet_5F00_StartScreenProductivity_5F00_01_5F00_072A1240.jpg Pretty conclusive. If you can brand something a “phablet” and sleep at night you’re made of sterner stuff than I am, but that’s beside the point. It’s explicit in the post that Microsoft are expecting a broader range of form factors for WP8, but they stop short of quite calling out tablet size. The extra columns and resolution definitely back that up, so why stop at a 6 inch “phablet”? Sadly, the string of numbers there don’t really look like a Lumia model number – that would be a bit tendentious even for a speculative blog post about a single screenshot. “Productivity” is interesting too. I get into this a bit more below, but this is a pretty clear pitch for a business device. What it looks like Something that would look quite decent on a 7 inch screen, but something a bit too vertical to go toe-to-toe with the Surface. Certainly, it would look a lot better on a large-factor phone than any of the current models. Those tiles are going to get cramped and a bit ugly if the handsets aren’t getting bigger. What’s on it You have a bunch of missed calls, you rarely text, use a stocks app, and your budget spreadsheet and meeting notes are a thumb-reach away. Outlook is your main form of email. You care enough about LinkedIn to not only install its app but give it a huge live tile. There’s no beating about the bush here, the implicit persona is a corporate exec. With Nokia in the bag and Blackberry pushing daisies, that may not be a stupid play. There’s almost certainly a niche there if they can parlay their corporate credentials into filling it before BYOD (which functionally means an iPhone) reaches the late adopters. The really quite slick WP8 Office implementation ought to help here. This is the face they’ve chosen to present, the cultural milieu they’re normalizing for Windows Phone. It’s an iPhone for Serious Business Grown-ups. Could work, I guess. Does it mean anything? Is the latest WP8 update a sign that we can expect to see tablets running Windows Phone rather than WinRT? Well, WinRT tablets haven’t exactly taken off but I’m not quite going to make a leap like that just from a file name and a column of icons. I feel pretty safe, however, conjecturing that Microsoft would like to squeeze a WP8 “phablet” into the palm of every exec who’s ever grumbled about their Blackberry, and this release might get them a bit closer. If it works well incrementing up to larger devices, then that could be a fair hedge against WinRt crashing and burning any harder in the marketplace.

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• Do we still have a case against the goto statement? [closed]

  - by FredOverflow

  Possible Duplicate: Is it ever worthwhile using goto? In a recent article, Andrew Koenig writes: When asked why goto statements are harmful, most programmers will say something like "because they make programs hard to understand." Press harder, and you may well hear something like "I don't really know, but that's what I was taught." For that reason, I'd like to summarize Dijkstra's arguments. He then shows two program fragments, one without a goto and and one with a goto: if (n < 0) n = 0; Assuming that n is a variable of a built-in numeric type, we know that after this code, n is nonnegative. Suppose we rewrite this fragment: if (n >= 0) goto nonneg; n = 0; nonneg: ; In theory, this rewrite should have the same effect as the original. However, rewriting has changed something important: It has opened the possibility of transferring control to nonneg from anywhere else in the program. I emphasized the part that I don't agree with. Modern languages like C++ do not allow goto to transfer control arbitrarily. Here are two examples: You cannot jump to a label that is defined in a different function. You cannot jump over a variable initialization. Now consider composing your code of tiny functions that adhere to the single responsibility principle: int clamp_to_zero(int n) { if (n >= 0) goto n_is_not_negative: n = 0; n_is_not_negative: return n; } The classic argument against the goto statement is that control could have transferred from anywhere inside your program to the label n_is_not_negative, but this simply is not (and was never) true in C++. If you try it, you will get a compiler error, because labels are scoped. The rest of the program doesn't even see the name n_is_not_negative, so it's just not possible to jump there. This is a static guarantee! Now, I'm not saying that this version is better then the one without the goto, but to make the latter as expressive as the first one, we would at least have to insert a comment, or even better yet, an assertion: int clamp_to_zero(int n) { if (n < 0) n = 0; // n is not negative at this point assert(n >= 0); return n; } Note that you basically get the assertion for free in the goto version, because the condition n >= 0 is already written in line 1, and n = 0; satisfies the condition trivially. But that's just a random observation. It seems to me that "don't use gotos!" is one of those dogmas like "don't use multiple returns!" that stem from a time where the real problem were functions of hundreds or even thousand of lines of code. So, do we still have a case against the goto statement, other than that it is not particularly useful? I haven't written a goto in at least a decade, but it's not like I was running away in terror whenever I encountered one. 1 Ideally, I would like to see a strong and valid argument against gotos that still holds when you adhere to established programming principles for clean code like the SRP. "You can jump anywhere" is not (and has never been) a valid argument in C++, and somehow I don't like teaching stuff that is not true. 1: Also, I have never been able to resurrect even a single velociraptor, no matter how many gotos I tried :(

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• SQLAuthority News – Who I Am And How I Got Here – True Story as Blog Post

  - by pinaldave

  Here are few of the sample questions I get every day? “Give me shortcut to become superstar?” “How do I become like you?” “Which book I should read so I know everything?” “Can you share your secret to be successful? I want to know it but do not share with others.” There is generic answer I always give is to work hard and read good educational material or watch good online videos. One of the emails really caught my attention. It was from a friend and SQL Server Expert John Sansom (Blog | Twitter). He wrote if I would like to share my story with the world about “Who I am and How I got Here”. I was very much intrigued with his suggestion. John is one guy I respect a lot. Every single topic he writes, I read it with dedication. I eagerly wait for his Weekly Summary of Best SQL Links. If you have not read them, you are missing something out. Writing a guest post for him was like walking in memory lane. I remembered the time when I was beginning my career and I was bit overconfident and bit naive. I had my share of mistakes when I started my career. As time passed by I realize the truth. Well, we all do mistakes. Though, I am proud that as soon as I know my mistakes I corrected them. I never acted on impulse or when I am angry. I think that alone has helped me analysis the situation better and become better human being. During the course, I have lost my ego and it is replaced by passion. I am much more happy and successful in my work. Quite often people ask me if I am always online and wether I have family or not. Honestly, I am able to work hard because of my family. They support me and they encourage me to be enjoy in what I do. They support everything I do and personally, I do not miss a single occasion to join them in daily chores of fun. If there was a shortcut to success – I want know. I learnt SQL Server hard way and I am still learning. There are so many things, I have to learn. There is not enough time to learn everything which we want to learn. I am constantly working on it every day. I welcome you to join my journey as well. Please join me with my journey to learn SQL Server – more the merrier. I have written a story of my life as a guest post.  Read Here: A Journey to SQL Authority Special thanks to John Sansom (Blog | Twitter) for giving me space to talk my story. Indeed I am honored. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: About Me, Best Practices, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Anatomy of a .NET Assembly - Signature encodings

  - by Simon Cooper

  If you've just joined this series, I highly recommend you read the previous posts in this series, starting here, or at least these posts, covering the CLR metadata tables. Before we look at custom attribute encoding, we first need to have a brief look at how signatures are encoded in an assembly in general. Signature types There are several types of signatures in an assembly, all of which share a common base representation, and are all stored as binary blobs in the #Blob heap, referenced by an offset from various metadata tables. The types of signatures are: Method definition and method reference signatures. Field signatures Property signatures Method local variables. These are referenced from the StandAloneSig table, which is then referenced by method body headers. Generic type specifications. These represent a particular instantiation of a generic type. Generic method specifications. Similarly, these represent a particular instantiation of a generic method. All these signatures share the same underlying mechanism to represent a type Representing a type All metadata signatures are based around the ELEMENT_TYPE structure. This assigns a number to each 'built-in' type in the framework; for example, Uint16 is 0x07, String is 0x0e, and Object is 0x1c. Byte codes are also used to indicate SzArrays, multi-dimensional arrays, custom types, and generic type and method variables. However, these require some further information. Firstly, custom types (ie not one of the built-in types). These require you to specify the 4-byte TypeDefOrRef coded token after the CLASS (0x12) or VALUETYPE (0x11) element type. This 4-byte value is stored in a compressed format before being written out to disk (for more excruciating details, you can refer to the CLI specification). SzArrays simply have the array item type after the SZARRAY byte (0x1d). Multidimensional arrays follow the ARRAY element type with a series of compressed integers indicating the number of dimensions, and the size and lower bound of each dimension. Generic variables are simply followed by the index of the generic variable they refer to. There are other additions as well, for example, a specific byte value indicates a method parameter passed by reference (BYREF), and other values indicating custom modifiers. Some examples... To demonstrate, here's a few examples and what the resulting blobs in the #Blob heap will look like. Each name in capitals corresponds to a particular byte value in the ELEMENT_TYPE or CALLCONV structure, and coded tokens to custom types are represented by the type name in curly brackets. A simple field: int intField; FIELD I4 A field of an array of a generic type parameter (assuming T is the first generic parameter of the containing type): T[] genArrayField FIELD SZARRAY VAR 0 An instance method signature (note how the number of parameters does not include the return type): instance string MyMethod(MyType, int&, bool[][]); HASTHIS DEFAULT 3 STRING CLASS {MyType} BYREF I4 SZARRAY SZARRAY BOOLEAN A generic type instantiation: MyGenericType<MyType, MyStruct> GENERICINST CLASS {MyGenericType} 2 CLASS {MyType} VALUETYPE {MyStruct} For more complicated examples, in the following C# type declaration: GenericType<T> : GenericBaseType<object[], T, GenericType<T>> { ... } the Extends field of the TypeDef for GenericType will point to a TypeSpec with the following blob: GENERICINST CLASS {GenericBaseType} 3 SZARRAY OBJECT VAR 0 GENERICINST CLASS {GenericType} 1 VAR 0 And a static generic method signature (generic parameters on types are referenced using VAR, generic parameters on methods using MVAR): TResult[] GenericMethod<TInput, TResult>( TInput, System.Converter<TInput, TOutput>); GENERIC 2 2 SZARRAY MVAR 1 MVAR 0 GENERICINST CLASS {System.Converter} 2 MVAR 0 MVAR 1 As you can see, complicated signatures are recursively built up out of quite simple building blocks to represent all the possible variations in a .NET assembly. Now we've looked at the basics of normal method signatures, in my next post I'll look at custom attribute application signatures, and how they are different to normal signatures.

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