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  • Cowboy Agile?

    - by Robert May
    In a previous post, I outlined the rules of Scrum.  This post details one of those rules. I’ve often heard similar phrases around Scrum that clue me in to someone who doesn’t understand Scrum.  The phrases go something like this: “We don’t do Agile because the idea of letting people just do whatever they want is wrong.  We believe in a more structured approach.” (i.e. Work is Prison, and I’m the Warden!) “I love Agile.  Agile lets us do whatever we want!” (Cowboy Agile?) “We’re Agile, but we use a process that I’ve created.” (Cowboy Agile?) All of those phrases have one thing in common:  The assumption that Agile, and I mean Scrum, lets you do whatever you want.  This is simply not true. Executing Scrum properly requires more dedication, rigor, and diligence than happens in most traditional development methods. Scrum and Waterfall Compared Since Scrum and Waterfall are two of the most commonly used methodologies, a little bit of contrasting and comparing is in order. Waterfall Scrum A project manager defines all tasks and then manages the tasks that team members are working on. The team members define the tasks and estimates of the stories for the current iteration.  Any team member may work on any task in the iteration. Usually only a few milestones that need to be met, the milestones are measured in months, and these milestones are expected to be missed.  Little work is ever done to improve estimates and poor estimators can hide behind high estimates. Stories must be delivered every iteration, milestones are measured in hours, and the team is expected to figure out why their estimates were wrong, even when they were under.  Repeated misses can get the entire team fired. Partially completed work is normal. Partially completed work doesn’t count. Nobody knows the task you’re working on. Everyone knows what you’re working on, whether or not you’re making progress and how much longer you think its going to take, in hours. Little requirement to show working code.  Prototypes are ok. Working code must be shown each iteration.  No smoke and mirrors allowed.  Testing is done in lengthy cycles at the end of development.  Developers aren’t held accountable. Testing is part of the team.  If the testers don’t accept the story as complete, the team can’t count it.  Complete means that the story’s functionality works as designed.  The team can’t have any open defects on the story. Velocity is rarely truly measured and difficult to evaluate. Velocity is integral to the process and can be seen at a glance and everyone in the company knows what it is. A business analyst writes requirements.  Designers mock up screens.  Developers hide behind “I did it just like the spec doc told me to and made the screen exactly like the picture” Developers are expected to collaborate in real time.  If a design is bad or lacks needed details, the developers are required to get it right in the iteration, because all software must be functional.  Designers and Business Analysts are part of the team and must do their work in iterations slightly ahead of the developers. Upper Management is often surprised.  “You told me things were going well two months ago!” Management receives updates at the end of every iteration showing them exactly what the team did and how that compares to what' is remaining in the backlog.  Managers know every iteration what their money is buying. Status meetings are rare or don’t occur.  Email is a primary form of communication. Teams coordinate every single day with each other and use other high bandwidth communication channels to make sure they’re making progress.  Email is used only as a last resort.  Instead, team members stand up, walk to each other, and talk, face to face.  If that’s not possible, they pick up the phone. IF someone asks what happened, its at the end of a lengthy development cycle measured in months, and nobody really knows why it happened. Someone asks what happened every iteration.  The team talks about what happened, and then adapts to make sure that what happened either never happens again or happens every time.   That’s probably enough for now.  As you can see, a lot is required of Scrum teams! One of the key differences in Scrum is that the burden for many activities is shifted to a group of people who share responsibility, instead of a single person having responsibility.  This is a very good thing, since small groups usually come up with better and more insightful work than single individuals.  This shift also results in better velocity.  Team members can take vacations and the rest of the team simply picks up the slack.  With Waterfall, if a key team member takes a vacation, delays can ensue. Scrum requires much more out of every team member and as a result, Scrum teams outperform non-Scrum teams working 60 hour weeks. Recommended Reading Everyone considering Scrum should read Mike Cohn’s excellent book, User Stories Applied. Technorati Tags: Agile,Scrum,Waterfall

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  • Why enumerator structs are a really bad idea

    - by Simon Cooper
    If you've ever poked around the .NET class libraries in Reflector, I'm sure you would have noticed that the generic collection classes all have implementations of their IEnumerator as a struct rather than a class. As you will see, this design decision has some rather unfortunate side effects... As is generally known in the .NET world, mutable structs are a Very Bad Idea; and there are several other blogs around explaining this (Eric Lippert's blog post explains the problem quite well). In the BCL, the generic collection enumerators are all mutable structs, as they need to keep track of where they are in the collection. This bit me quite hard when I was coding a wrapper around a LinkedList<int>.Enumerator. It boils down to this code: sealed class EnumeratorWrapper : IEnumerator<int> { private readonly LinkedList<int>.Enumerator m_Enumerator; public EnumeratorWrapper(LinkedList<int> linkedList) { m_Enumerator = linkedList.GetEnumerator(); } public int Current { get { return m_Enumerator.Current; } } object System.Collections.IEnumerator.Current { get { return Current; } } public bool MoveNext() { return m_Enumerator.MoveNext(); } public void Reset() { ((System.Collections.IEnumerator)m_Enumerator).Reset(); } public void Dispose() { m_Enumerator.Dispose(); } } The key line here is the MoveNext method. When I initially coded this, I thought that the call to m_Enumerator.MoveNext() would alter the enumerator state in the m_Enumerator class variable and so the enumeration would proceed in an orderly fashion through the collection. However, when I ran this code it went into an infinite loop - the m_Enumerator.MoveNext() call wasn't actually changing the state in the m_Enumerator variable at all, and my code was looping forever on the first collection element. It was only after disassembling that method that I found out what was going on The MoveNext method above results in the following IL: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000, [1] valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator CS$0$0001) L_0000: nop L_0001: ldarg.0 L_0002: ldfld valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: stloc.1 L_0008: ldloca.s CS$0$0001 L_000a: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000f: stloc.0 L_0010: br.s L_0012 L_0012: ldloc.0 L_0013: ret } Here, the important line is 0002 - m_Enumerator is accessed using the ldfld operator, which does the following: Finds the value of a field in the object whose reference is currently on the evaluation stack. So, what the MoveNext method is doing is the following: public bool MoveNext() { LinkedList<int>.Enumerator CS$0$0001 = this.m_Enumerator; bool CS$1$0000 = CS$0$0001.MoveNext(); return CS$1$0000; } The enumerator instance being modified by the call to MoveNext is the one stored in the CS$0$0001 variable on the stack, and not the one in the EnumeratorWrapper class instance. Hence why the state of m_Enumerator wasn't getting updated. Hmm, ok. Well, why is it doing this? If you have a read of Eric Lippert's blog post about this issue, you'll notice he quotes a few sections of the C# spec. In particular, 7.5.4: ...if the field is readonly and the reference occurs outside an instance constructor of the class in which the field is declared, then the result is a value, namely the value of the field I in the object referenced by E. And my m_Enumerator field is readonly! Indeed, if I remove the readonly from the class variable then the problem goes away, and the code works as expected. The IL confirms this: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000) L_0000: nop L_0001: ldarg.0 L_0002: ldflda valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000c: stloc.0 L_000d: br.s L_000f L_000f: ldloc.0 L_0010: ret } Notice on line 0002, instead of the ldfld we had before, we've got a ldflda, which does this: Finds the address of a field in the object whose reference is currently on the evaluation stack. Instead of loading the value, we're loading the address of the m_Enumerator field. So now the call to MoveNext modifies the enumerator stored in the class rather than on the stack, and everything works as expected. Previously, I had thought enumerator structs were an odd but interesting feature of the BCL that I had used in the past to do linked list slices. However, effects like this only underline how dangerous mutable structs are, and I'm at a loss to explain why the enumerators were implemented as structs in the first place. (interestingly, the SortedList<TKey, TValue> enumerator is a struct but is private, which makes it even more odd - the only way it can be accessed is as a boxed IEnumerator!). I would love to hear people's theories as to why the enumerators are implemented in such a fashion. And bonus points if you can explain why LinkedList<int>.Enumerator.Reset is an explicit implementation but Dispose is implicit... Note to self: never ever ever code a mutable struct.

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  • C#/.NET Little Wonders: Static Char Methods

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Often times in our code we deal with the bigger classes and types in the BCL, and occasionally forgot that there are some nice methods on the primitive types as well.  Today we will discuss some of the handy static methods that exist on the char (the C# alias of System.Char) type. The Background I was examining a piece of code this week where I saw the following: 1: // need to get the 5th (offset 4) character in upper case 2: var type = symbol.Substring(4, 1).ToUpper(); 3:  4: // test to see if the type is P 5: if (type == "P") 6: { 7: // ... do something with P type... 8: } Is there really any error in this code?  No, but it still struck me wrong because it is allocating two very short-lived throw-away strings, just to store and manipulate a single char: The call to Substring() generates a new string of length 1 The call to ToUpper() generates a new upper-case version of the string from Step 1. In my mind this is similar to using ToUpper() to do a case-insensitive compare: it isn’t wrong, it’s just much heavier than it needs to be (for more info on case-insensitive compares, see #2 in 5 More Little Wonders). One of my favorite books is the C++ Coding Standards: 101 Rules, Guidelines, and Best Practices by Sutter and Alexandrescu.  True, it’s about C++ standards, but there’s also some great general programming advice in there, including two rules I love:         8. Don’t Optimize Prematurely         9. Don’t Pessimize Prematurely We all know what #8 means: don’t optimize when there is no immediate need, especially at the expense of readability and maintainability.  I firmly believe this and in the axiom: it’s easier to make correct code fast than to make fast code correct.  Optimizing code to the point that it becomes difficult to maintain often gains little and often gives you little bang for the buck. But what about #9?  Well, for that they state: “All other things being equal, notably code complexity and readability, certain efficient design patterns and coding idioms should just flow naturally from your fingertips and are no harder to write then the pessimized alternatives. This is not premature optimization; it is avoiding gratuitous pessimization.” Or, if I may paraphrase: “where it doesn’t increase the code complexity and readability, prefer the more efficient option”. The example code above was one of those times I feel where we are violating a tacit C# coding idiom: avoid creating unnecessary temporary strings.  The code creates temporary strings to hold one char, which is just unnecessary.  I think the original coder thought he had to do this because ToUpper() is an instance method on string but not on char.  What he didn’t know, however, is that ToUpper() does exist on char, it’s just a static method instead (though you could write an extension method to make it look instance-ish). This leads me (in a long-winded way) to my Little Wonders for the day… Static Methods of System.Char So let’s look at some of these handy, and often overlooked, static methods on the char type: IsDigit(), IsLetter(), IsLetterOrDigit(), IsPunctuation(), IsWhiteSpace() Methods to tell you whether a char (or position in a string) belongs to a category of characters. IsLower(), IsUpper() Methods that check if a char (or position in a string) is lower or upper case ToLower(), ToUpper() Methods that convert a single char to the lower or upper equivalent. For example, if you wanted to see if a string contained any lower case characters, you could do the following: 1: if (symbol.Any(c => char.IsLower(c))) 2: { 3: // ... 4: } Which, incidentally, we could use a method group to shorten the expression to: 1: if (symbol.Any(char.IsLower)) 2: { 3: // ... 4: } Or, if you wanted to verify that all of the characters in a string are digits: 1: if (symbol.All(char.IsDigit)) 2: { 3: // ... 4: } Also, for the IsXxx() methods, there are overloads that take either a char, or a string and an index, this means that these two calls are logically identical: 1: // check given a character 2: if (char.IsUpper(symbol[0])) { ... } 3:  4: // check given a string and index 5: if (char.IsUpper(symbol, 0)) { ... } Obviously, if you just have a char, then you’d just use the first form.  But if you have a string you can use either form equally well. As a side note, care should be taken when examining all the available static methods on the System.Char type, as some seem to be redundant but actually have very different purposes.  For example, there are IsDigit() and IsNumeric() methods, which sound the same on the surface, but give you different results. IsDigit() returns true if it is a base-10 digit character (‘0’, ‘1’, … ‘9’) where IsNumeric() returns true if it’s any numeric character including the characters for ½, ¼, etc. Summary To come full circle back to our opening example, I would have preferred the code be written like this: 1: // grab 5th char and take upper case version of it 2: var type = char.ToUpper(symbol[4]); 3:  4: if (type == 'P') 5: { 6: // ... do something with P type... 7: } Not only is it just as readable (if not more so), but it performs over 3x faster on my machine:    1,000,000 iterations of char method took: 30 ms, 0.000050 ms/item.    1,000,000 iterations of string method took: 101 ms, 0.000101 ms/item. It’s not only immediately faster because we don’t allocate temporary strings, but as an added bonus there less garbage to collect later as well.  To me this qualifies as a case where we are using a common C# performance idiom (don’t create unnecessary temporary strings) to make our code better. Technorati Tags: C#,CSharp,.NET,Little Wonders,char,string

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  • My First Weeks at Red Gate

    - by Jess Nickson
    Hi, my name’s Jess and early September 2012 I started working at Red Gate as a Software Engineer down in The Agency (the Publishing team). This was a bit of a shock, as I didn’t think this team would have any developers! I admit, I was a little worried when it was mentioned that my role was going to be different from normal dev. roles within the company. However, as luck would have it, I was placed within a team that was responsible for the development and maintenance of Simple-Talk and SQL Server Central (SSC). I felt rather unprepared for this role. I hadn’t used many of the technologies involved and of those that I had, I hadn’t looked at them for quite a while. I was, nevertheless, quite excited about this turn of events. As I had predicted, the role has been quite challenging so far. I expected that I would struggle to get my head round the large codebase already in place, having never used anything so much as a fraction of the size of this before. However, I was perhaps a bit naive when it came to how quickly things would move. I was required to start learning/remembering a number of different languages and technologies within time frames I would never have tried to set myself previously. Having said that, my first week was pretty easy. It was filled with meetings that were designed to get the new starters up to speed with the different departments, ideals and rules within the company. I also attended some lightning talks being presented by other employees, which were pretty useful. These occur once a fortnight and normally consist of around four speakers. In my spare time, we set up the Simple-Talk codebase on my computer and I started exploring it and worked on my first feature – redirecting requests for URLs that used incorrect casing! It was also during this time that I was given my first introduction to test-driven development (TDD) with Michael via a code kata. Although I had heard of the general ideas behind TDD, I had definitely never tried it before. Indeed, I hadn’t really done any automated testing of code before, either. The session was therefore very useful and gave me insights as to some of the coding practices used in my team. Although I now understand the importance of TDD, it still seems odd in my head and I’ve yet to master how to sensibly step up the functionality of the code a bit at a time. The second week was both easier and more difficult than the first. I was given a new project to work on, meaning I was no longer using the codebase already in place. My job was to take some designs, a WordPress theme, and some initial content and build a page that allowed users of the site to read provided resources and give feedback. This feedback could include their thoughts about the resource, the topics covered and the page design itself. Although it didn’t sound the most challenging of projects when compared to fixing bugs in our current codebase, it nevertheless provided a few sneaky problems that had me stumped. I really enjoyed working on this project as it allowed me to play around with HTML, CSS and JavaScript; all things that I like working with but rarely have a chance to use. I completed the aims for the project on time and was happy with the final outcome – though it still needs a good designer to take a look at it! I am now into my third week at Red Gate and I have temporarily been pulled off the website from week 2. I am again back to figuring out the Simple-Talk codebase. Monday provided me with the chance to learn a bunch of new things: system level testing, Selenium and Python. I was set the challenge of testing a bug fix dealing with the search bars in Simple-Talk. The exercise was pretty fun, although Mike did have to point me in the right direction when I started making the tests a bit too complex. The rest of the week looks set to be focussed on pair programming with Mike as we work together on a new feature. I look forward to the challenges that still face me and hope that I will be able to get up to speed quickly. *fingers crossed*

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  • C#/.NET Little Wonders &ndash; Cross Calling Constructors

    - by James Michael Hare
    Just a small post today, it’s the final iteration before our release and things are crazy here!  This is another little tidbit that I love using, and it should be fairly common knowledge, yet I’ve noticed many times that less experienced developers tend to have redundant constructor code when they overload their constructors. The Problem – repetitive code is less maintainable Let’s say you were designing a messaging system, and so you want to create a class to represent the properties for a Receiver, so perhaps you design a ReceiverProperties class to represent this collection of properties. Perhaps, you decide to make ReceiverProperties immutable, and so you have several constructors that you can use for alternative construction: 1: // Constructs a set of receiver properties. 2: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable, bool isBuffered) 3: { 4: ReceiverType = receiverType; 5: Source = source; 6: IsDurable = isDurable; 7: IsBuffered = isBuffered; 8: } 9: 10: // Constructs a set of receiver properties with buffering on by default. 11: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable) 12: { 13: ReceiverType = receiverType; 14: Source = source; 15: IsDurable = isDurable; 16: IsBuffered = true; 17: } 18:  19: // Constructs a set of receiver properties with buffering on and durability off. 20: public ReceiverProperties(ReceiverType receiverType, string source) 21: { 22: ReceiverType = receiverType; 23: Source = source; 24: IsDurable = false; 25: IsBuffered = true; 26: } Note: keep in mind this is just a simple example for illustration, and in same cases default parameters can also help clean this up, but they have issues of their own. While strictly speaking, there is nothing wrong with this code, logically, it suffers from maintainability flaws.  Consider what happens if you add a new property to the class?  You have to remember to guarantee that it is set appropriately in every constructor call. This can cause subtle bugs and becomes even uglier when the constructors do more complex logic, error handling, or there are numerous potential overloads (especially if you can’t easily see them all on one screen’s height). The Solution – cross-calling constructors I’d wager nearly everyone knows how to call your base class’s constructor, but you can also cross-call to one of the constructors in the same class by using the this keyword in the same way you use base to call a base constructor. 1: // Constructs a set of receiver properties. 2: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable, bool isBuffered) 3: { 4: ReceiverType = receiverType; 5: Source = source; 6: IsDurable = isDurable; 7: IsBuffered = isBuffered; 8: } 9: 10: // Constructs a set of receiver properties with buffering on by default. 11: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable) 12: : this(receiverType, source, isDurable, true) 13: { 14: } 15:  16: // Constructs a set of receiver properties with buffering on and durability off. 17: public ReceiverProperties(ReceiverType receiverType, string source) 18: : this(receiverType, source, false, true) 19: { 20: } Notice, there is much less code.  In addition, the code you have has no repetitive logic.  You can define the main constructor that takes all arguments, and the remaining constructors with defaults simply cross-call the main constructor, passing in the defaults. Yes, in some cases default parameters can ease some of this for you, but default parameters only work for compile-time constants (null, string and number literals).  For example, if you were creating a TradingDataAdapter that relied on an implementation of ITradingDao which is the data access object to retreive records from the database, you might want two constructors: one that takes an ITradingDao reference, and a default constructor which constructs a specific ITradingDao for ease of use: 1: public TradingDataAdapter(ITradingDao dao) 2: { 3: _tradingDao = dao; 4:  5: // other constructor logic 6: } 7:  8: public TradingDataAdapter() 9: { 10: _tradingDao = new SqlTradingDao(); 11:  12: // same constructor logic as above 13: }   As you can see, this isn’t something we can solve with a default parameter, but we could with cross-calling constructors: 1: public TradingDataAdapter(ITradingDao dao) 2: { 3: _tradingDao = dao; 4:  5: // other constructor logic 6: } 7:  8: public TradingDataAdapter() 9: : this(new SqlTradingDao()) 10: { 11: }   So in cases like this where you have constructors with non compiler-time constant defaults, default parameters can’t help you and cross-calling constructors is one of your best options. Summary When you have just one constructor doing the job of initializing the class, you can consolidate all your logic and error-handling in one place, thus ensuring that your behavior will be consistent across the constructor calls. This makes the code more maintainable and even easier to read.  There will be some cases where cross-calling constructors may be sub-optimal or not possible (if, for example, the overloaded constructors take completely different types and are not just “defaulting” behaviors). You can also use default parameters, of course, but default parameter behavior in a class hierarchy can be problematic (default values are not inherited and in fact can differ) so sometimes multiple constructors are actually preferable. Regardless of why you may need to have multiple constructors, consider cross-calling where you can to reduce redundant logic and clean up the code.   Technorati Tags: C#,.NET,Little Wonders

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  • Columnstore Case Study #2: Columnstore faster than SSAS Cube at DevCon Security

    - by aspiringgeek
    Preamble This is the second in a series of posts documenting big wins encountered using columnstore indexes in SQL Server 2012 & 2014.  Many of these can be found in my big deck along with details such as internals, best practices, caveats, etc.  The purpose of sharing the case studies in this context is to provide an easy-to-consume quick-reference alternative. See also Columnstore Case Study #1: MSIT SONAR Aggregations Why Columnstore? As stated previously, If we’re looking for a subset of columns from one or a few rows, given the right indexes, SQL Server can do a superlative job of providing an answer. If we’re asking a question which by design needs to hit lots of rows—DW, reporting, aggregations, grouping, scans, etc., SQL Server has never had a good mechanism—until columnstore. Columnstore indexes were introduced in SQL Server 2012. However, they're still largely unknown. Some adoption blockers existed; yet columnstore was nonetheless a game changer for many apps.  In SQL Server 2014, potential blockers have been largely removed & they're going to profoundly change the way we interact with our data.  The purpose of this series is to share the performance benefits of columnstore & documenting columnstore is a compelling reason to upgrade to SQL Server 2014. The Customer DevCon Security provides home & business security services & has been in business for 135 years. I met DevCon personnel while speaking to the Utah County SQL User Group on 20 February 2012. (Thanks to TJ Belt (b|@tjaybelt) & Ben Miller (b|@DBADuck) for the invitation which serendipitously coincided with the height of ski season.) The App: DevCon Security Reporting: Optimized & Ad Hoc Queries DevCon users interrogate a SQL Server 2012 Analysis Services cube via SSRS. In addition, the SQL Server 2012 relational back end is the target of ad hoc queries; this DW back end is refreshed nightly during a brief maintenance window via conventional table partition switching. SSRS, SSAS, & MDX Conventional relational structures were unable to provide adequate performance for user interaction for the SSRS reports. An SSAS solution was implemented requiring personnel to ramp up technically, including learning enough MDX to satisfy requirements. Ad Hoc Queries Even though the fact table is relatively small—only 22 million rows & 33GB—the table was a typical DW table in terms of its width: 137 columns, any of which could be the target of ad hoc interrogation. As is common in DW reporting scenarios such as this, it is often nearly to optimize for such queries using conventional indexing. DevCon DBAs & developers attended PASS 2012 & were introduced to the marvels of columnstore in a session presented by Klaus Aschenbrenner (b|@Aschenbrenner) The Details Classic vs. columnstore before-&-after metrics are impressive. Scenario Conventional Structures Columnstore ? SSRS via SSAS 10 - 12 seconds 1 second >10x Ad Hoc 5-7 minutes (300 - 420 seconds) 1 - 2 seconds >100x Here are two charts characterizing this data graphically.  The first is a linear representation of Report Duration (in seconds) for Conventional Structures vs. Columnstore Indexes.  As is so often the case when we chart such significant deltas, the linear scale doesn’t expose some the dramatically improved values corresponding to the columnstore metrics.  Just to make it fair here’s the same data represented logarithmically; yet even here the values corresponding to 1 –2 seconds aren’t visible.  The Wins Performance: Even prior to columnstore implementation, at 10 - 12 seconds canned report performance against the SSAS cube was tolerable. Yet the 1 second performance afterward is clearly better. As significant as that is, imagine the user experience re: ad hoc interrogation. The difference between several minutes vs. one or two seconds is a game changer, literally changing the way users interact with their data—no mental context switching, no wondering when the results will appear, no preoccupation with the spinning mind-numbing hurry-up-&-wait indicators.  As we’ve commonly found elsewhere, columnstore indexes here provided performance improvements of one, two, or more orders of magnitude. Simplified Infrastructure: Because in this case a nonclustered columnstore index on a conventional DW table was faster than an Analysis Services cube, the entire SSAS infrastructure was rendered superfluous & was retired. PASS Rocks: Once again, the value of attending PASS is proven out. The trip to Charlotte combined with eager & enquiring minds let directly to this success story. Find out more about the next PASS Summit here, hosted this year in Seattle on November 4 - 7, 2014. DevCon BI Team Lead Nathan Allan provided this unsolicited feedback: “What we found was pretty awesome. It has been a game changer for us in terms of the flexibility we can offer people that would like to get to the data in different ways.” Summary For DW, reports, & other BI workloads, columnstore often provides significant performance enhancements relative to conventional indexing.  I have documented here, the second in a series of reports on columnstore implementations, results from DevCon Security, a live customer production app for which performance increased by factors of from 10x to 100x for all report queries, including canned queries as well as reducing time for results for ad hoc queries from 5 - 7 minutes to 1 - 2 seconds. As a result of columnstore performance, the customer retired their SSAS infrastructure. I invite you to consider leveraging columnstore in your own environment. Let me know if you have any questions.

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  • Grid Layouts in ADF Faces using Trinidad

    - by frank.nimphius
    Normal 0 false false false EN-US X-NONE X-NONE /* 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:"Times New Roman","serif";} ADF Faces does provide a data table component but none to define grid layouts. Grids are common in web design and developers often try HTML table markup wrapped in an f:verbatim tag or directly added the page to build a desired layout. Usually these attempts fail, showing unpredictable results, However, ADF Faces does not provide a table layout component, but Apache MyFaces Trinidad does. The Trinidad trh:tableLayout component is a thin wrapper around the HTML table element and contains a series of row layout elements, trh:rowLayout. Each trh:rowLayout component may contain one or many trh:cellLayout components to format cells content. <trh:tableLayout id="tl1" halign="left">   <trh:rowLayout id="rl1" valign="top" halign="left">     <trh:cellFormat id="cf1" width="100" header="true">        <af:outputLabel value="Label 1" id="ol1"/>     </trh:cellFormat>     <trh:cellFormat id="cf2" header="true"                               width="300">        <af:outputLabel value="Label 2" id="outputLabel1"/>        </trh:cellFormat>      </trh:rowLayout>      <trh:rowLayout id="rowLayout1" valign="top" halign="left">        <trh:cellFormat id="cellFormat1" width="100" header="false">           <af:outputLabel value="Label 3" id="outputLabel2"/>        </trh:cellFormat>     </trh:rowLayout>        ... </trh:tableLayout> To add the Trinidad tag library to your ADF Faces projects ... Open the Component Palette and right mouse click into it Choose "Edit Tag Libraries" and select the Trinidad components. Move them to the "Selected Libraries" section and Ok the dialog.The first time you drag a Trinidad component to a page, the web.xml file is updated with the required filters Note: The Trinidad tags don't participate in the ADF Faces RC geometry management. However, they are JSF components that are part of the JSF request lifecycle. Normal 0 false false false EN-US X-NONE X-NONE /* 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:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} ADF Faces RC components work well with Trinidad layout components that don't use PPR. The PPR implementation of Trinidad is different from the one in ADF Faces. However, when you mix ADF Faces components with Trinidad components, avoid Trinidad components that have integrated PPR behavior. Only use passive Trinidad components.See:http://myfaces.apache.org/trinidad/trinidad-api/tagdoc/trh_tableLayout.htmlhttp://myfaces.apache.org/trinidad/trinidad-api/tagdoc/trh_rowLayout.htmlhttp://myfaces.apache.org/trinidad/trinidad-api/tagdoc/trh_cellFormat.html .

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  • Customizing UPK outputs (Part 2 - Player)

    - by [email protected]
    There are a few things that can be done to give the Player output a personalized look to match your corporate branding. In my previous post, I talked about changing the logo. In addition to the logo, you can change the graphic in the heading, button colors, border colors and many other items. Prior to making any customizations, I strongly recommend making a copy of the existing Player style. This will give you a backup in case things go wrong. I'd also recommend that you create your own brand. This way, when you install the newest updates from us, your brand will remain intact. Creating your own brand is pretty easy. Make sure you have modify permissions on the publishing styles directory, if you are using a multi-user installation. Under the Publishing/Styles folder, create a new folder with your company name. Copy all the publishing styles from the UPK folder to your newly created folder. Now, when you go through the Publishing wizard, you will have two categories to choose from: the UPK category or your custom category. Now, for updating the Player output. First, the graphic that appears on the right hand side of the Player. If you're using a multi-user installation, check out the player style from your custom brand. Open the player style. Open the img folder. The file named "banner_image.png" represents the graphic that appears on the right hand side of the player. It is currently sized at 425 x 54. Try to keep your graphic about the same size. Rename your graphic file to be "banner_image.png", and drag it into the img folder. Save the package. Check in the package if you are in a multi-user installation. You've just updated the banner heading! Next, let's work on updating some of the other colors in the player. All the customizable areas are located in the skin.css file which is in the root of the Player style. Many of our customers update the colors to match their own theme. You don't have to be a programmer to make these changes, honest. :) To change the colors in the player: Make a copy of the original skin.css file. (This is to make sure you have a working version to revert to, in case something goes wrong.) Open the skin.css file from the Player package. You can edit it using Notepad. Make the desired changes. Save the file. Save the package. Publish to view your new changes. When you open the skin.css, you will see groupings like this: .headerDivbar { height: 21px; background-color: #CDE2FD; } Change the value of the background-color to the color of your choice. Note that you cannot use "red" as a color, but rather you should enter the hexadecimal color code. If you don't know the color code, search the web for "hexadecimal colors" and you'll find many sites to provide the information. Here are a few of the variables that you can update. Heading: .headerDivbar -this changes the color of the banner that appears under the graphic Button colors: .navCellOn - changes the color of the mode buttons when your mouse is hovering on them. .navCellOff - changes the color of the mode buttons when the mouse is not over them Lines: .thorizontal - this is the color of the horizontal lines surrounding the outline .tvertical - this is the color of the vertical lines on the left and right margin in the outline. .tsep - this is the color of the line that separates the outline from the content area Search frame: .tocSearchColor - this is the color of the search area .tocFrameText - this is the background color of the TOC tree. Hint: If you want to try out the changes prior to updating the style, you can update the skin.css in some content you've already published for the player (it's located in the css folder of the player package). This way, you can immediately see the changes without going through publishing. Once you're happy with the changes, update the skin.css in player style. Want to customize more? Refer to the "Customizing the Player" section of the Content Development manual for more details on all the options in the skin.css that can be changed, and pictures of what each variable controls. I'd love to see how you've customized the player for your corporate needs. Also, if there are other areas of the player you'd like to modify but have not been able to, let us know. Feel free to share your thoughts in the comments. --Maria Cozzolino, Manager of Requirements & UI Design for UPK

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  • To Bit or Not To Bit

    - by Johnm
    'Twas a long day of troubleshooting and firefighting and now, with most of the office vacant, you face a blank scripting window to create a new table in his database. Many questions circle your mind like dirty water gurgling down the bathtub drain: "How normalized should this table be?", "Should I use an identity column?", "NVarchar or Varchar?", "Should this column be NULLABLE?", "I wonder what apple blue cheese bacon cheesecake tastes like?" Well, there are times when the mind goes it's own direction. A Bit About Bit At some point during your table creation efforts you will encounter the decision of whether to use the bit data type for a column. The bit data type is an integer data type that recognizes only the values of 1, 0 and NULL as valid. This data type is often utilized to store yes/no or true/false values. An example of its use would be a column called [IsGasoline] which would be intended to contain the value of 1 if the row's subject (a car) had a gasoline engine and a 0 if the subject did not have a gasoline engine. The bit data type can even be found in some of the system tables of SQL Server. For example, the sysssispackages table in the msdb database which contains SQL Server Integration Services Package information for the packages stored in SQL Server. This table contains a column called [IsEncrypted]. A value of 1 indicates that the package has been encrypted while the value of 0 indicates that it is not. I have learned that the most effective way to disperse the crowd that surrounds the office coffee machine is to engage into SQL Server debates. The bit data type has been one of the most reoccurring, as well as the most enjoyable, of these topics. It contains a practical side and a philosophical side. Practical Consideration This data type certainly has its place and is a valuable option for database design; but it is often used in situations where the answer is really not a pure true/false response. In addition, true/false values are not very informative or scalable. Let's use the previously noted [IsGasoline] column for illustration. While on the surface it appears to be a rather simple question when evaluating a car: "Does the car have a gasoline engine?" If the person entering data is entering a row for a Jeep Liberty, the response would be a 1 since it has a gasoline engine. If the person is entering data is entering a row for a Chevrolet Volt, the response would be a 0 since it is an electric engine. What happens when a person is entering a row for the gasoline/electric hybrid Toyota Prius? Would one person's conclusion be consistent with another person's conclusion? The argument could be made that the current intent for the database is to be used only for pure gasoline and pure electric engines; but this is where the scalability issue comes into play. With the use of a bit data type a database modification and data conversion would be required if the business decided to take on hybrid engines. Whereas, alternatively, if the int data type were used as a foreign key to a reference table containing the engine type options, the change to include the hybrid option would only require an entry into the reference table. Philosophical Consideration Since the bit data type is often used for true/false or yes/no data (also called Boolean) it presents a philosophical conundrum of what to do about the allowance of the NULL value. The inclusion of NULL in a true/false or yes/no response simply violates the logical principle of bivalence which states that "every proposition is either true or false". If NULL is not true, then it must be false. The mathematical laws of Boolean logic support this concept by stating that the only valid values of this scenario are 1 and 0. There is another way to look at this conundrum: NULL is also considered to be the absence of a response. In other words, it is the equivalent to "undecided". Anyone who watches the news can tell you that polls always include an "undecided" option. This could be considered a valid option in the world of yes/no/dunno. Through out all of these considerations I have discovered one absolute certainty: When you have found a person, or group of persons, who are willing to entertain a philosophical debate of the bit data type, you have found some true friends.

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  • A deadlock was detected while trying to lock variables in SSIS

    Error: 0xC001405C at SQL Log Status: A deadlock was detected while trying to lock variables "User::RowCount" for read/write access. A lock cannot be acquired after 16 attempts. The locks timed out. Have you ever considered variable locking when building your SSIS packages? I expect many people haven’t just because most of the time you never see an error like the one above. I’ll try and explain a few key concepts about variable locking and hopefully you never will see that error. First of all, what is all this variable locking all about? Put simply SSIS variables have to be locked before they can be accessed, and then of course unlocked once you have finished with them. This is baked into SSIS, presumably to reduce the risk of race conditions, but with that comes some additional overhead in that you need to be careful to avoid lock conflicts in some scenarios. The most obvious place you will come across any hint of locking (no pun intended) is the Script Task or Script Component with their ReadOnlyVariables and ReadWriteVariables properties. These two properties allow you to enter lists of variables to be used within the task, or to put it another way, these lists of variables to be locked, so that they are available within the task. During the task pre-execute phase the variables and locked, you then use them during the execute phase when you code is run, and then unlocked for you during the post-execute phase. So by entering the variable names in one of the two list, the locking is taken care of for you, and you just read and write to the Dts.Variables collection that is exposed in the task for the purpose. As you can see in the image above, the variable PackageInt is specified, which means when I write the code inside that task I don’t have to worry about locking at all, as shown below. public void Main() { // Set the variable value to something new Dts.Variables["PackageInt"].Value = 199; // Raise an event so we can play in the event handler bool fireAgain = true; Dts.Events.FireInformation(0, "Script Task Code", "This is the script task raising an event.", null, 0, ref fireAgain); Dts.TaskResult = (int)ScriptResults.Success; } As you can see as well as accessing the variable, hassle free, I also raise an event. Now consider a scenario where I have an event hander as well as shown below. Now what if my event handler uses tries to use the same variable as well? Well obviously for the point of this post, it fails with the error quoted previously. The reason why is clearly illustrated if you consider the following sequence of events. Package execution starts Script Task in Control Flow starts Script Task in Control Flow locks the PackageInt variable as specified in the ReadWriteVariables property Script Task in Control Flow executes script, and the On Information event is raised The On Information event handler starts Script Task in On Information event handler starts Script Task in On Information event handler attempts to lock the PackageInt variable (for either read or write it doesn’t matter), but will fail because the variable is already locked. The problem is caused by the event handler task trying to use a variable that is already locked by the task in Control Flow. Events are always raised synchronously, therefore the task in Control Flow that is raising the event will not regain control until the event handler has completed, so we really do have un-resolvable locking conflict, better known as a deadlock. In this scenario we can easily resolve the problem by managing the variable locking explicitly in code, so no need to specify anything for the ReadOnlyVariables and ReadWriteVariables properties. public void Main() { // Set the variable value to something new, with explicit lock control Variables lockedVariables = null; Dts.VariableDispenser.LockOneForWrite("PackageInt", ref lockedVariables); lockedVariables["PackageInt"].Value = 199; lockedVariables.Unlock(); // Raise an event so we can play in the event handler bool fireAgain = true; Dts.Events.FireInformation(0, "Script Task Code", "This is the script task raising an event.", null, 0, ref fireAgain); Dts.TaskResult = (int)ScriptResults.Success; } Now the package will execute successfully because the variable lock has already been released by the time the event is raised, so no conflict occurs. For those of you with a SQL Engine background this should all sound strangely familiar, and boils down to getting in and out as fast as you can to reduce the risk of lock contention, be that SQL pages or SSIS variables. Unfortunately we cannot always manage the locking ourselves. The Execute SQL Task is very often used in conjunction with variables, either to pass in parameter values or get results out. Either way the task will manage the locking for you, and will fail when it cannot lock the variables it requires. The scenario outlined above is clear cut deadlock scenario, both parties are waiting on each other, so it is un-resolvable. The mechanism used within SSIS isn’t actually that clever, and whilst the message says it is a deadlock, it really just means it tried a few times, and then gave up. The last part of the error message is actually the most accurate in terms of the failure, A lock cannot be acquired after 16 attempts. The locks timed out.  Now this may come across as a recommendation to always manage locking manually in the Script Task or Script Component yourself, but I think that would be an overreaction. It is more of a reminder to be aware that in high concurrency scenarios, especially when sharing variables across multiple objects, locking is important design consideration. Update – Make sure you don’t try and use explicit locking as well as leaving the variable names in the ReadOnlyVariables and ReadWriteVariables lock lists otherwise you’ll get the deadlock error, you cannot lock a variable twice!

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  • Best way to store a large amount of game objects and update the ones onscreen

    - by user3002473
    Good afternoon guys! I'm a young beginner game developer working on my first large scale game project and I've run into a situation where I'm not quite sure what the best solution may be (if there is a lone solution). The question may be vague (if anyone can think of a better title after having read the question, please edit it) or broad but I'm not quite sure what to do and I thought it would help just to discuss the problem with people more educated in the field. Before we get started, here are some of the questions I've looked at for help in the past: Best way to keep track of game objects Elegant way to simulate large amounts of entities within a game world What is the most efficient container to store dynamic game objects in? I've also read articles about different data structures commonly used in games to store game objects such as this one about slot maps, but none of them are really what I'm looking for. Also, if it helps at all I'm using Python 3 to design the game. It has to be Python 3, if I could I would use C++ or Unityscript or something else, but I'm restricted to having to use Python 3. My game will be a form of side scroller shooter game. In said game the player will traverse large rooms with large amounts of enemies and other game objects to update (think some of the larger areas in Cave Story or Iji). The player obviously can't see the entire room all at once, so there is a viewport that follows the player around and renders only a selection of the room and the game objects that it contains. This is not a foreign concept. The part that's getting me confused has to do with how certain game objects are updated. Some of them are to be updated constantly, regardless of whether or not they can be seen. Other objects however are only to be updated when they are onscreen (for example, an enemy would only be updated to react to the player when it is onscreen or when it is in a certain range of the screen). Another problem is that game objects have to be easily referable by other game objects; something that happens in the player's update() method may affect another object in the world. Collision detection in games is always a serious problem. I need a way of containing the game objects such that it minimizes the number of cases when testing for collisions against one another. The final problem is that of creating and destroying game objects. I think this problem is pretty self explanatory. To store the game objects then I've considered a number of different methods. The original method I had was to simply store all the objects in a hash table by an id. This method was simple, and decently fast as it allows all the objects to be looked up in O(1) complexity, and also allows them to be deleted fairly easily. Hash collisions would not be a major problem; I wasn't originally planning on using computer generated ids to store the game objects I was going to rely on them all using ids given to them by the game designer (such names would be strings like 'Player' or 'EnemyWeapon4'), and even if I did use computer generated ids, if I used a decent hashing algorithm then the chances of collisions would be around 1 in 4 billion. The problem with using a hash table however is that it is inefficient in checking to see what objects are in range of the viewport. Considering the fact that certain game objects move (as well as the viewport itself), the only solution I could think of in order to only update objects that are in the viewport would be to iterate through every object in the hash table and check if it is in the viewport or not, updating only the ones that are in the valid area. This would be incredibly slow in scenarios where the amount of game objects exceeds 500, or even 200. The second solution was to store everything in a 2-d list. The world is partitioned up into cells (a tilemap essentially), where each cell or tile is the same size and is square. Each cell would contain a list of the game objects that are currently occupying it (each game object would be inserted into a cell depending on the center of the object's collision mask). A 2-d list would allow me to take the top-left and bottom-right corners of the viewport and easily grab a rectangular area of the grid containing only the cells containing entities that are in valid range to be updated. This method also solves the problem of collision detection; when I take an entity I can find the cell that it is currently in, then check only against entities in it's cell and the 8 cells around it. One problem with this system however is that it prohibits easy lookup of game objects. One solution I had would be to simultaneously keep a hash table that would contain all the positions of the objects in the 2-d list indexed by the id of said object. The major problem with a 2-d list is that it would need to be rebuilt every single game frame (along with the hash table of object positions), which may be a serious detriment to game speed. Both systems have ups and downs and seem to solve some of each other's problems, however using them both together doesn't seem like the best solution either. If anyone has any thoughts, ideas, suggestions, comments, opinions or solutions on new data structures or better implementations of the existing data structures I have in mind, please post, any and all criticism and help is welcome. Thanks in advance! EDIT: Please don't close the question because it has a bad title, I'm just bad with names!

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  • Walmart and Fusion Apps

    - by ultan o'broin
    Photograph: Misha Vaughan I attended Fusion Apps (yes, I know I am supposed to say "Oracle Fusion Applications", but stuffy old style guides are a turn-off in interwebs conversations) User Experience Advocate (FXA) training in Long Beach, California last week; a suitable location as ODTUG KSCOPE 11 was kicking off and key players were in the area. As a member of Oracle's Apps-UX team I know the Fusion Apps messaging, natch, and done some other Fusion Apps go-to-market content work too. For the messaging details themselves, see Lonneke Dikmans (@lonnekedikmans) great blog, by the way. However, I wanted some 'formal' training combined with the opportunity to meet and learn from people already out there delivering those messages. The idea in me reaching out to Misha Vaughan, Apps-UX FXA maven, to get me onto this training was that in addition to my UX knowledge, I could leverage my location in EMEA and hit up customer events more quickly and easily. Those local user groups do like to hear the voice of locals too you know (so I need to work on that mid-Atlantic accent). I'm looking forward to such opportunities. The training was all smashing stuff, just the right level of detail, delivered professionally and with great style and humor. I was especially honored to be paired off for my er, coaching with Debra Lilley (@debralilley), who shared with everyone all kinds of tips and insights from her experiences of delivering the message and demo. For me, that was the real power of the FXA event--the communal, conversational aspect--the meeting up with people who had done all this for real, the sharing in their experiences, while learning along with other newbies. Sorry, but that all-important social aspect doesn't work so well with remote meetings. Katie Candland (Apps-UX) gave us a great tour of the Fusion Apps demo and included some useful presentational tips too (any excuse to buy that iPad). It's clear to me that the Fusion Apps messaging and demos really come alive with real-world examples that local application users will recognize, and I picked up some "yes, that's my job made easier" scene-stealers from Debra and Karen Brownfield too, to add to the great ones already provided. This power of examples shouldn't surprise anyone, they've long been a mainstay of applications user assistance, popular with users. We'll offer customers different types of example topics in the Fusion Apps online help too (stay tuned), and we know from research how important those 3S's (stories, scenarios, and simulations) are to users when they consume and apply information. Well, we've got the simulation, now it's time for more stories and scenarios. If you get a chance to participate in an FXA event (whether you are an Oracle employee or otherwise), I'd encourage it. It's committing your time and energy for sure, but I got real bang for the buck from it for my everyday job too. Listening to the room's feedback on the application demo really brought our internal design work to life, and I picked up on some things that I need to follow up on (like how you alphabetically sort stuff in other languages). User experience is after all, about users. What will I be doing next, and what would I like to see happen? Obviously, I need to develop my story-telling links with the people I met in Long Beach and do some practicing with the materials, and then get out there and deliver them at a suitable location. The demo is what it is right now, and that's a super-rich demo that I know everyone will want to see and ask questions about. Then, as mentioned by attendees at the FXA event, follow up on those translated and localized messages for EMEA (and APAC), that deal with different statutory or reporting requirements of the target markets. Given my background I would say that, wouldn't I? However, language is part of the UX, and international revenue is greater than US-only revenue for Oracle, so yes dear, we all need to get over the fact that enterprise apps users don't all speak, or want to speak, American-English. Most importantly perhaps, the continued development of a strong messaging community between Oracle and partners and customers where we can swap and share those FXA messaging stories and scenarios about Fusion Apps in a conversational way. The more the better, a combination of online and face-to-face meetings. I must also mention the great dinner after the event at Parker's Lighthouse, and the fun myself and Andrew Gilmour (Apps-UX) had at our end of the table talking about just about everything except Fusion Apps with Ronald Van Luttikhuizen and Ben Prusinski (who now understands the difference between Cork and Dublin people. I hope). Thanks to all the Apps-UXers who helped bring the FXA training to town, and to Debra and all the others that I am too jetlagged to mention right who were instrumental in making it happen for me. Here's to the next one. And the Walmart angle? That was me doing my Robert Scoble (ScO'bilizer?)-style guerilla smart phone research in Walmart in Long Beach, before the FXA event. It's all about stories for me. You can read more about it on the appslab blog (see the comments).

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  • How many developers before continuous integration becomes effective for us?

    - by Carnotaurus
    There is an overhead associated with continuous integration, e.g., set up, re-training, awareness activities, stoppage to fix "bugs" that turn out to be data issues, enforced separation of concerns programming styles, etc. At what point does continuous integration pay for itself? EDIT: These were my findings The set-up was CruiseControl.Net with Nant, reading from VSS or TFS. Here are a few reasons for failure, which have nothing to do with the setup: Cost of investigation: The time spent investigating whether a red light is due a genuine logical inconsistency in the code, data quality, or another source such as an infrastructure problem (e.g., a network issue, a timeout reading from source control, third party server is down, etc., etc.) Political costs over infrastructure: I considered performing an "infrastructure" check for each method in the test run. I had no solution to the timeout except to replace the build server. Red tape got in the way and there was no server replacement. Cost of fixing unit tests: A red light due to a data quality issue could be an indicator of a badly written unit test. So, data dependent unit tests were re-written to reduce the likelihood of a red light due to bad data. In many cases, necessary data was inserted into the test environment to be able to accurately run its unit tests. It makes sense to say that by making the data more robust then the test becomes more robust if it is dependent on this data. Of course, this worked well! Cost of coverage, i.e., writing unit tests for already existing code: There was the problem of unit test coverage. There were thousands of methods that had no unit tests. So, a sizeable amount of man days would be needed to create those. As this would be too difficult to provide a business case, it was decided that unit tests would be used for any new public method going forward. Those that did not have a unit test were termed 'potentially infra red'. An intestesting point here is that static methods were a moot point in how it would be possible to uniquely determine how a specific static method had failed. Cost of bespoke releases: Nant scripts only go so far. They are not that useful for, say, CMS dependent builds for EPiServer, CMS, or any UI oriented database deployment. These are the types of issues that occured on the build server for hourly test runs and overnight QA builds. I entertain that these to be unnecessary as a build master can perform these tasks manually at the time of release, esp., with a one man band and a small build. So, single step builds have not justified use of CI in my experience. What about the more complex, multistep builds? These can be a pain to build, especially without a Nant script. So, even having created one, these were no more successful. The costs of fixing the red light issues outweighed the benefits. Eventually, developers lost interest and questioned the validity of the red light. Having given it a fair try, I believe that CI is expensive and there is a lot of working around the edges instead of just getting the job done. It's more cost effective to employ experienced developers who do not make a mess of large projects than introduce and maintain an alarm system. This is the case even if those developers leave. It doesn't matter if a good developer leaves because processes that he follows would ensure that he writes requirement specs, design specs, sticks to the coding guidelines, and comments his code so that it is readable. All this is reviewed. If this is not happening then his team leader is not doing his job, which should be picked up by his manager and so on. For CI to work, it is not enough to just write unit tests, attempt to maintain full coverage, and ensure a working infrastructure for sizable systems. The bottom line: One might question whether fixing as many bugs before release is even desirable from a business prespective. CI involves a lot of work to capture a handful of bugs that the customer could identify in UAT or the company could get paid for fixing as part of a client service agreement when the warranty period expires anyway.

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  • First Foray&ndash;About timeout

    - by SQLMonger
    It has been quite a while since I signed up for this blog site and high time that something was posted.  I have a list of topics that I will be working through and posting.  Some I am sure will have been posted by others, but I will be sticking to the technical problems and challenges that I’ve recently faced, and the solutions that worked for me.  My motto when learning something new has always been “My kingdom for an example!”, and I plan on delivering useful examples here so others can learn from my efforts, failures and successes.   A bit of background about me… My name is Clayton Groom. I am a founding partner of a consulting firm in St. Louis Missouri, Covenant Technology Partners, LLC and focus on SQL Server Data Warehouse design, Analysis Services and Enterprise Reporting solutions.  I have been working with SQL Server since the early nineties, when it still only ran on OS/2. I love solving puzzles and technical challenges.   Enough about me… On to a real problem… SSIS Connection Time outs versus Command Time outs Last week, I was working on automating the processing for a large Analysis Services cube.  I had reworked an SSIS package and script task originally posted by Vidas Matelis that automates the process of adding new and dropping old partitions to/from an Analysis Services cube.  I had the package working great, tested, and ready for deployment.  It basically performs a query against the source system to determine if there is new data in the warehouse that will require a new partition to be added to the cube, and it checks the cube to see if there are any partitions that are present that are no longer needed in a rolling 60 month window. My client uses Tivoli for running all their production jobs, and not SQL Agent, so I had to build a command line file for Tivoli to use to run the package. Everything was going great. I had tested the command file from my development workstation using an XML configuration file to pass in server-specific parameters into the package when executed using the DTExec utility. With all the pieces ready, I updated the dtsconfig file to point to the UAT environment and started working with the Tivoli developer to test the job.  On the first run, the job failed, and from what I could see in the SSIS log, it had failed because of a timeout. Other errors in the log made me think that perhaps the connection string had not been passed into the package correctly. We bumped the Connection Manager  timeout values from 20 seconds to 120 seconds and tried again. The job still failed. After changing the command line to use the /SET option instead of the /CONFIGFILE option, we tested again, and again failure. After a number more failed attempts, and getting the Teradata DBA involved to monitor and see if we were connecting and failing or just failing to connect, we determined that the job was indeed connecting to the server and then disconnecting itself after 30 seconds.  This seemed odd, as we had the timeout values for the connection manager set to 180 seconds by then.  At this point one of the DBA’s found a post on the Teradata forum that had the clues to the puzzle: There is a separate “CommandTimeout” custom property on the Data source object that may needed to be adjusted for longer running queries.  I opened up the SSIS package, opened the data flow task that generated the partition list table and right-clicked on the data source. from the context menu, I selected “Show Advanced Editor” and found the property. Sure enough, it was set to 30 seconds. The CommandTimeout property can also be edited in the SSIS Properties sheet. In order to determine how long the timeout needed to be, I ran the query from the task in the development environment and received a response in a matter of seconds.  I then tried the same query against the production database and waited several minutes for a response. This did not seem to be a reasonable response time for the query involved, and indeed it wasn’t. The Teradata DBA’s adjusted the query governor settings for the service account I was testing with, and we were able to get the response back down under a minute.  Still, I set the CommandTimeout property to a much higher value in case the job was ever started during a time of high-demand on the production server. With this change in place, the job finally completed successfully.  The lesson learned for me was two-fold: Always compare query execution times between development and production environments, and don’t assume that production will always be faster.  With higher user demands, query governors, and a whole lot more data, the execution time of even what might seem to be simple queries can vary greatly. SSIS Connection time out settings do not affect command time outs.  Connection timeouts control how long the package will wait for a response from the server before assuming the server is not available or is not responding. Command time outs control how long a task will wait for results to start being returned before deciding that the server is not responding. Both lessons seem pretty straight forward, and I felt pretty sheepish once I finally figured out what the issue was.  To be fair though, In the 5+ years that I have been working with SSIS, I could only recall one other time where I had to set the CommandTimeout property, and that memory only resurfaced while I was penning this post.

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  • Ok it has been pointed out to me

    - by Ratman21
    That it seems my blog is more of poor me or pity me or I deserve a job blog.   Hmmm I wont say, I have not wined here as I have used this blog to vent my frustration on the whole out of work thing (lack of money, self worth, family issues and the never end bills coming my way) but, it was also me trying to reach to others in the same boat as well as advertising, hay I am out here, employers.   It was also said, that I don’t have any thing listed here on me, like a cover letter or resume. Well there is but, it was so many months and post ago. Also what I had posted is not current. So here is my most current cover and resume.   Scott L Newman 45219 Dutton Way Callahan, Fl. 32011 To Whom It May Concern: I am really interested in the IT vacancie that you have listed for your company. Maybe I don’t have all the qualifications you want (hold on don’t hit delete yet) yet! But maybe I do, as I have over 20 + years experience in "IT” RIGHT NOW.   Read the rest of my cover and my resume. You will see what my “IT” skills are and it will Show that I can to this work! I can bring to your company along with my, can do attitude, a broad range of skills, including: Certified CompTIA A+, Security+  and Network+ Technician §         2.5 years (NOC) Network experience on large Cisco based Wan – UK to Austria §         20 years experience MIS/DP – Yes I can do IBM mainframes and Tandem  non-stops too §         18 years experience as technical Help Desk support – panicking users, no problem §         18 years experience with PC/Server based system, intranet and internet systems §         10+ years experienced on: Microsoft Office, Windows XP and Data Network Fundamentals (YES I do windows) §         Strong trouble shooting skills for software, hard ware and circuit issues (and I can tell you what kind of horrors I had to face on all of them). §         Very experienced on working with customers on problems – again panicking users, no problem §         Working experience with Remote Access (VPN/SecurID) – I didn’t just study them I worked on/with them §         Skilled in getting info for and creating documentation for Operation procedures (I don’t just wait for them to give it to me I go out and get it. Waiting for info on working applications is, well dumb) Multiple software languages (Hey I have done some programming) And much more experiences in “IT” (Mortgage, stocks and financial information systems experience and have worked “IT” in a hospital) Can multitask, also have ability to adapt to change and learn quickly. (once was put in charge of a system that I had not worked with for over two years. Talk about having to relearn and adapt to changes but, I did it.) I would welcome the opportunity to further discuss this position with you. If you have questions or would like to schedule an interview, please contact me by phone at 904-879-4880 or on my cell 352-356-0945 or by e-mail at [email protected] or leave a message on my web site (http://beingscottnewman.webs.com/). I have enclosed/attached my resume for your review and I look forward to hearing from you.   Thank you for taking a moment to consider my cover letter and resume. I appreciate how busy you are. Sincerely, Scott L. Newman    Scott L. Newman 45219 Dutton Way, Callahan, FL 32011? H (904)879-4880 C (352)356-0945 ? [email protected] Web - http://beingscottnewman.webs.com/                                                       ______                                                                                       OBJECTIVE To obtain a Network Operation or Helpdesk position.     PROFILE Information Technology Professional with 20+ years of experience. Volunteer website creator and back-up sound technician at True Faith Christian Fellowship. CompTIA A+, Network+ and Security+ Certified.   TECHNICAL AND PROFESSIONAL SKILLS   §         Technical Support §         Frame Relay §         Microsoft Office Suite §         Inventory Management §         ISDN §         Windows NT/98/XP §         Client/Vendor Relations §         CICS §         Cisco Routers/Switches §         Networking/Administration §         RPG §         Helpdesk §         Website Design/Dev./Management §         Assembler §         Visio §         Programming §         COBOL IV §               EDUCATION ? New HorizonsComputerLearningCenter, Jacksonville, Florida – CompTIA A+, Security+ and Network+ Certified.             Currently working on CCNA Certification ?MottCommunity College, Flint, Michigan – Associates Degree - Data Processing and General Education ? Currently studying Japanese     PROFESSIONAL             TrueFaithChristianFellowshipChurch – Callahan, FL, October 2009 – Present Web site Tech ·        Web site Creator/tech, back up song leader and back up sound technician. Note church web site is (http://ambassadorsforjesuschrist.webs.com/) U.S. Census (temp employee) Feb. 23 to March 8, 2010 ·        Enumerator for NassauCounty   ThomasCreekBaptistChurch – Callahan, FL,     June 2008 – September 2009 Churchsound and video technician      ·        sound and video technician           Fidelity National Information Services ? Jacksonville, FL ? February 01, 2005 to October 28, 2008 Client Server Dev/Analyst I ·        Monitored Multiple Debit Card sites, Check Authorization customers and the Card Auth system (AuthNet) for problems with the sites, connections, servers (on our LAN) and/or applications ·        Night (NOC) Network operator for a large Wide Area Network (WAN) ·        Monitored Multiple Check Authorization customers for problems with circuits, routers and applications ·        Resolved circuit and/or router issues or assist circuit carrier in resolving issue ·        Resolved application problems or assist application support in resolution ·        Liaison between customer and application support ·        Maintained and updated the NetOps Operation procedures Guide ·        Kept the listing of equipment on the raised floor updated ·        Involved in the training of all Night Check and Card server operation operators ·        FNIS acquired Certegy in 2005. Was one of 3 kept on.   Certegy ? St.Pete, FL ? August 31, 2003 to February 1, 2005 Senior NetOps Operator(FNIS acquired Certegy in 2005 all of above jobs/skills were same as listed in FNIS) ·        Converting Documentation to Adobe format ·        Sole trainer of day/night shift System Management Center operators (SMC) ·        Equifax spun off Card/Check Dept. as Certegy. Certegy terminated contract with EDS. One of six in the whole IT dept that was kept on.   EDS  (Certegy Account) ? St.Pete, FL ? July 1, 1999 to August 31, 2003 Senior NetOps Operator ·        Equifax outsourced the NetOps dept. to EDS in 1999. ·        Same job skills as listed above for FNIS.   Equifax ? St.Pete&Tampa, FL ? January 1, 1991 to July 1, 1999 NetOps/Tandem Operator ·        All of the above for FNIS, except for circuit and router issues ·        Operated, monitored and trouble shot Tandem mainframe and servers on LAN ·        Supported in the operation of the Print, Tape and Microfiche rooms ·        Equifax acquired TelaCredit in 1991.   TelaCredit ? Tampa, FL ? June 28, 1989 to January 1, 1991 Tandem Operator ·        Operated and monitored Tandem Non-stop systems for Card and Check Auths ·        Operated multiple high-speed Laser printers and Microfiche printers ·        Mounted, filed and maintained 18 reel-to-reel mainframe tape drives, cartridges tape drives and tape library.

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  • Phones, Nokia, Microsoft and More

    - by Bill Evjen
    The phone revolution that is under way at the moment is insanely interesting and continuously full of buzz about directions, failures, and promises. The movement started with Apple completely reinventing what a smart phone was all about and now we have the followers. Though – don’t dismiss the followers, they are usually the ones that come out with the leap frog products when most of the world is thinking about jumping on. Remember the often used analogy – the USA invented the TV – but it was Japan that took it to the next level and now all TVs are from somewhere else other than the USA. Really there are two camps for the phones – the Cool Kids and other kids that no one wants to hang out with anymore. When it comes to cool – for some reason, the phone is an important part of that factor. Everyone wants to show their phone and its configuration (apps installed, etc) to their friends as a sign of (1) “I have money” and (2) I have smarts/tastes/style/etc when it comes to my applications that are on my phone. For those that don’t know – the Cool Kids include: Apple – this is quite obvious as everything Apple produces is in the cool camp. Just having an Apple product on your person means you can dance. Google – this is one of the more interesting releases as they have created something called Android (which in it’s own right is a major brand in itself). Microsoft – you might be saying “Really, Microsoft is cool?”. I would argue that they are indeed cool as it is now associated with XBOX 360, Kinect, and Windows 7. Gone are the days of Bob and that silly paperclip. Well – that’s it. There is nobody else I would stick in that camp. The other kids that weren’t picked for that dodgeball team include: Nokia Motorola Palm Blackberry and many many more The sad part of all this is that no matter what this second camp does now, it won’t be able to get out of this bucket easily. They will always be associated as yesterday’s technology and that association will drive the sales of the phone purchasers of the world. For those in that group, the only possible way out is to get invited to the cool club by one of the cool club members in the hope that their coolness somehow rubs off. To me, this is the move that Nokia is making. They are at this point where they have realized that they don’t have the full scope of the required end to end solution to make this all work. They have the plants to build the phones and the reach of the retailers that sell what they have. What they are missing is the proper operating system for the new world of multi-touch form factor phones. Even the companies that come up with some sort of new operating system for this type of new device, they are still associated with the yesterday and lack the developer community behind them to be the real wave of adoption that this market needs. Think about that – this is a major different between Nokia/Blackberry when you compare it to the likes of Apple, Google, and Microsoft. These three powerhouses having a very large and strong development community that will eagerly take on new initiatives using the skillsets that they have already cultivated over the years of already working with the company. This then results in a plethora of applications that are then placed on an app store of some kind. The developer gets a cut and then Apple/Google/Microsoft then get their cut. It is definitely a win-win. None of the other phone companies and wannabies can provide the same results. What Microsoft was missing was the major phone manufactures coming on board to create and push forward with the phones that are required to start the wave. This is where Nokia can come in and help Microsoft. They have the ability to promote the Windows Phone operating system on a new wave of phones. This does mean that Nokia will sell phones, but they lose out on the application store that they might have been thinking about making some money on as well as controlling the end to end solution. What is interesting is in questioning to oneself if Microsoft will purchase Nokia. It really depends upon how they want to compete and with whom Microsoft views as the major competitor. For instance, they can purchase Nokia and have their own hardware company and distribution network for phones – thereby taking on a model that is quite similar to Apple. On the other hand, they could just leave it up to the phone hardware companies such as Nokia and others to build and promote phones in a model that is similar to Google. Both ways have pluses and minuses. If they own the phone manufacturer, they really can put some thought into the design and technical specifications of the phone that is really designed to exactly how they want it. Microsoft has shown that they have this ability – especially with the XBOX initiative they have done over the years. Think about how good and powerful they have moved forward with XBOX – and I am not talking about just copying what others are doing, but coming up with leapfrog products that are steps ahead of everyone else. Though, if they didn’t do it themselves, they could then leave it up to the phone manufacturers to drive each other to build better and better phones that run the Microsoft OS – competition drives better products. We have seen this with the Android line of phones that are out there on the market. I have read a lot about Nokia investors really upset about the new Microsoft relationship – but really, this is a great thing. I for one am a fan of this relationship (I am also a Nokia stock holder btw). This will mean better days for Nokia.

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  • Siemens AG, Sector Healthcare, Increases Transparency and Improves Customer Loyalty with Web Portal Solution

    - by Kellsey Ruppel
    Siemens AG, Sector Healthcare, Increases Transparency and Improves Customer Loyalty with Web Portal Solution CUSTOMER AND PARTNER INFORMATION Customer Name – Siemens AG, Sector Healthcare Customer Revenue – 73,515 Billion Euro (2011, Siemens AG total) Customer Quote – “The realization of our complex requirements within a very short amount of time was enabled through the competent implementation partner Sapient, who fully used the  very broad scope of standard functionality provided in the Oracle WebCenter Portal, and the management of customer services, who continuously supported the project setup. ” – Joerg Modlmayr, Project Manager, Healthcare Customer Service Portal, Siemens AG The Siemens Healthcare Sector is one of the world's largest suppliers to the healthcare industry and a trendsetter in medical imaging, laboratory diagnostics, medical information technology and hearing aids. Siemens offers its customers products and solutions for the entire range of patient care from a single source – from prevention and early detection to diagnosis, and on to treatment and aftercare. By optimizing clinical workflows for the most common diseases, Siemens also makes healthcare faster, better and more cost-effective. To ensure greater transparency, increased efficiency, higher user acceptance, and additional services, Siemens AG, Sector Healthcare, replaced several existing legacy portal solutions that could not meet the company’s future needs with Oracle WebCenter Portal. Various existing portal solutions that cannot meet future demands will be successively replaced by the new central service portal, which will also allow for the efficient and intuitive implementation of new service concepts.  With Oracle, doctors and hospitals using Siemens medical solutions now have access to a central information portal that provides important information and services at just the push of a button.  Customer Name – Siemens AG, Sector Healthcare Customer URL – www.siemens.com Customer Headquarters – Erlangen, Germany Industry – Industrial Manufacturing Employees – 360,000  Challenges – Replace disparate medical service portals to meet future demands and eliminate an  unnecessarily high level of administrative work caused by heterogeneous installations Ensure portals meet current user demands to improve user-acceptance rates and increase number of total users Enable changes and expansion through standard functionality to eliminate the need for reliance on IT and reduce administrative efforts and associated high costs Ensure efficient and intuitive implementation of new service concepts for all devices and systems Ensure hospitals and clinics to transparently monitor and measure services rendered for the various medical devices and systems  Increase electronic interaction and expand services to achieve a higher level of customer loyalty Solution –  Deployed Oracle WebCenter Portal to ensure greater transparency, and as a result, a higher level of customer loyalty  Provided a centralized platform for doctors and hospitals using Siemens’ medical technology solutions that provides important information and services at the push of a button Reduced significantly the administrative workload by centralizing the solution in the new customer service portal Secured positive feedback from customers involved in the pilot program developed by design experts from Oracle partner Sapient. The interfaces were created with customer needs in mind. The first survey taken shortly after implementation came back with 2.4 points on a scale of 0-3 in the category “customer service portal intuitiveness level” Met all requirements including alignment with the Siemens Style Guide without extensive programming Implemented additional services via the portal such as benchmarking options to ensure the optimal use of the Customer Device Park Provided option for documentation of all services rendered in conjunction with the medical technology systems to ensure that the value of the services are transparent for the decision makers in the hospitals  Saved and stored all machine data from approximately 100,000 remote systems in the central service and information platform Provided the option to register errors online and follow the call status in real-time on the portal Made  available at the push of a button all information on the medical technology devices used in hospitals or clinics—from security checks and maintenance activities to current device statuses Provided PDF format Service Performance Reports that summarize information from periods of time ranging from previous weeks up to one year, meeting medical product law requirements  Why Oracle – Siemens AG favored Oracle for many reasons, however, the company ultimately decided to go with Oracle due to the enormous range of functionality the solutions offered for the healthcare sector.“We are not programmers; we are service providers in the medical technology segment and focus on the contents of the portal. All the functionality necessary for internet-based customer interaction is already standard in Oracle WebCenter Portal, which is a huge plus for us. Having Oracle as our technology partner ensures that the product will continually evolve, providing a strong technology platform for our customer service portal well into the future,” said Joerg Modlmayr project manager, Healthcare Customer Service Portal, Siemens AG. Partner Involvement – Siemens AG selected Oracle Partner Sapient because the company offered a service portfolio that perfectly met Siemens’ requirements and had a wealth of experience implementing Oracle WebCenter Portal. Additionally, Sapient had designers with a very high level of expertise in usability—an aspect that Siemens considered to be of vast importance for the project.  “The Sapient team completely met all our expectations. Our tightly timed project was completed on schedule, and the positive feedback from our users proves that we set the right measures in terms of usability—all thanks to the folks at Sapient,” Modlmayr said.  Partner Name – Sapient GmbH Deutschland Partner URL – www.sapient.com

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  • Gamification at OOW

    - by erikanollwebb
    Last week was Oracle OpenWorld, and for those of you not in tech or downtown San Francisco, that might not mean a whole lot.  However, if you are familiar with it, Oracle OpenWorld is our premier customer event.  This year, more than 50,000 people attended.  It's not a good week to visit San Francisco on vacation because Oracle customers take over all the hotels in town!  It was crazy, but a lot of fun and it's a great opportunity for the Apps UX group to do customer research with a range of customers.  This year, more than 100+ customers and partners took the time to team up with our UX experts and provide feedback on new designs and ideas. Over three days,  UX teams conducted 8  one-on-one user feedback sessions, 4 focus groups and 7 surveys. In addition, we conducted a voice capture activity and were able to collect close to 70 speech samples at the lab and DEMOgrounds. This was a great opportunity for us to do some testing on some specific gamification concepts with a set of business analysts.  We pulled in 8 folks for a focus group on gamification concepts and whether they thought those would work for their teams. To get ready for this, my designer extraordinaire, Andrea Cantú, flew into town and we spent almost a week locked in a room together brainstorming design ideas.  We killed a few trees trying to get all of our concepts and other examples together in the process, but in the end, we put together a whole series of examples of how you might gamify an Oracle app (in this case, CRM).  Andrea is a genius for this kind of thing and the comps she created looked great.  Here's a picture of her hard at work!  We also had the good fortune to have my boss, Laurie Pattison and my usability contractor, Shobana Subramanian there to note take and observe as well.  Here's a few shots of us, hard at work preparing for the day (or checking out something on Laurie's iPhone...) To start things off, we gave an overview of gamification and I talked about what it's used for.  Then we gave the participants a scenario about our sales person and what we were trying to get her to do. It was a great opportunity to highlight what our business goals might be and why we might want to add game mechanics.  It was also a good way to get them thinking about how that might work for them in their environments and workplaces. There were some surprises for the day.  We asked how many of them were already familiar with the concept of gamification--only two people had heard of it and only one was using game mechanics in his work.  That's in contrast to a survey we just ran internally with folks in a dev org where almost 50% of about 450 respondents had heard of gamification.  As we discussed the ways game mechanics could be used, it became clear that many of the folks had seen some game mechanics in action but didn't know that's what they were.  We also noticed that the folks in this group felt that if they were trying to sell the concept in their orgs, they wouldn't call it gamification.  That's not a huge surprise to me--they said what we've heard in the past, that gamification does not seem like a serious term for enterprise software.  They said they'd sell it with the goals--as a means to increase behaviors by rewarding users for activities.  It's a funny problem.  The word puts some folks off, but at the same time, I haven't seen another one word description that quite captures the range of things that "gamification" can cover.  My guess is that the more mainstream the term becomes, the more desensitized we'll become to the idea the it's trivializing enterprise software in some way.  Still, it was interesting to note that this group still felt that they would not take this concept to their bosses or teams and call it "gamification".  They focused on the goals, and how we could incentivize desired behaviors with game mechanics.  As I have already stated in other posts, I feel like my org is more receptive to discussing how this is just a more transparent type of usability and user experience methods than talking about gamification.  That's the argument they said they would use. All in all, it was a good session.  I love getting to talk to customers, present ideas and concepts, and get their feedback and input.  It's the type of thing that really helps drive our designs and keeps us grounded in what our customers need/want.  We're already planning where to get more feedback opportunities in the coming months. 

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  • NetBeans, JSF, and MySQL Primary Keys using AUTO_INCREMENT

    - by MarkH
    I recently had the opportunity to spin up a small web application using JSF and MySQL. Having developed JSF apps with Oracle Database back-ends before and possessing some small familiarity with MySQL (sans JSF), I thought this would be a cakewalk. Things did go pretty smoothly...but there was one little "gotcha" that took more time than the few seconds it really warranted. The Problem Every DBMS has its own way of automatically generating primary keys, and each has its pros and cons. For the Oracle Database, you use a sequence and point your Java classes to it using annotations that look something like this: @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="POC_ID_SEQ") @SequenceGenerator(name="POC_ID_SEQ", sequenceName="POC_ID_SEQ", allocationSize=1) Between creating the actual sequence in the database and making sure you have your annotations right (watch those typos!), it seems a bit cumbersome. But it typically "just works", without fuss. Enter MySQL. Designating an integer-based field as PRIMARY KEY and using the keyword AUTO_INCREMENT makes the same task seem much simpler. And it is, mostly. But while NetBeans cranks out a superb "first cut" for a basic JSF CRUD app, there are a couple of small things you'll need to bring to the mix in order to be able to actually (C)reate records. The (RUD) performs fine out of the gate. The Solution Omitting all design considerations and activity (!), here is the basic sequence of events I followed to create, then resolve, the JSF/MySQL "Primary Key Perfect Storm": Fire up NetBeans. Create JSF project. Create Entity Classes from Database. Create JSF Pages from Entity Classes. Test run. Try to create record and hit error. It's a simple fix, but one that was fun to find in its completeness. :-) Even though you've told it what to do for a primary key, a MySQL table requires a gentle nudge to actually generate that new key value. Two things are needed to make the magic happen. First, you need to ensure the following annotation is in place in your Java entity classes: @GeneratedValue(strategy = GenerationType.IDENTITY) All well and good, but the real key is this: in your controller class(es), you'll have a create() function that looks something like this, minus the comment line and the setId() call in bold red type:     public String create() {         try {             // Assign 0 to ID for MySQL to properly auto_increment the primary key.             current.setId(0);             getFacade().create(current);             JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("CategoryCreated"));             return prepareCreate();         } catch (Exception e) {             JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));             return null;         }     } Setting the current object's primary key attribute to zero (0) prior to saving it tells MySQL to get the next available value and assign it to that record's key field. Short and simple…but not inherently obvious if you've never used that particular combination of NetBeans/JSF/MySQL before. Hope this helps! All the best, Mark

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  • Windows for IoT, continued

    - by Valter Minute
    Originally posted on: http://geekswithblogs.net/WindowsEmbeddedCookbook/archive/2014/08/05/windows-for-iot-continued.aspxI received many interesting feedbacks on my previous blog post and I tried to find some time to do some additional tests. Bert Kleinschmidt pointed out that pins 2,3 and 10 of the Galileo are connected directly to the SOC, while pin 13, the one used for the sample sketch is controlled via an I2C I/O expander. I changed my code to use pin 2 instead of 13 (just changing the variable assignment at the beginning of the code) and latency was greatly reduced. Now each pulse lasts for 1.44ms, 44% more than the expected time, but ways better that the result we got using pin 13. I also used SetThreadPriority to increase the priority of the thread that was running the sketch to THREAD_PRIORITY_HIGHEST but that didn't change the results. When I was using the I2C-controlled pin I tried the same and the timings got ways worse (increasing more than 10 times) and so I did not commented on that part, wanting to investigate the issua a bit more in detail. It seems that increasing the priority of the application thread impacts negatively the I2C communication. I tried to use also the Linux-based implementation (using a different Galileo board since the one provided by MS seems to use a different firmware) and the results of running the sample blink sketch modified to use pin 2 and blink the led for 1ms are similar to those we got on the same board running Windows. Here the difference between expected time and measured time is worse, getting around 3.2ms instead of 1 (320% compared to 150% using Windows but far from the 100.1% we got with the 8-bit Arduino). Both systems were not under load during the test, maybe loading some applications that use part of the CPU time would make those timings even less reliable, but I think that those numbers are enough to draw some conclusions. It may not be worth running a full OS if what you need is Arduino compatibility. The Arduino UNO is probably the best Arduino you can find to perform this kind of development. The Galileo running the Linux-based stack or running Windows for IoT is targeted to be a platform for "Internet of Things" devices, whatever that means. At the moment I don't see the "I" part of IoT. We have low level interfaces (SPI, I2C, the GPIO pins) that can be used to connect sensors but the support for connectivity is limited and the amount of work required to deliver some data to the cloud (using a secure HTTP request or a message queuing system like APMQS or MQTT) is still big and the rich OS underneath seems to not provide any help doing that.Why should I use sockets and can't access all the high level connectivity features we have on "full" Windows?I know that it's possible to use some third party libraries, try to build them using the Windows For IoT SDK etc. but this means re-inventing the wheel every time and can also lead to some IP concerns if used for products meant to be closed-source. I hope that MS and Intel (and others) will focus less on the "coolness" of running (some) Arduino sketches and more on providing a better platform to people that really want to design devices that leverage internet connectivity and the cloud processing power to deliver better products and services. Providing a reliable set of connectivity services would be a great start. Providing support for .NET would be even better, leaving native code available for hardware access etc. I know that those components may require additional storage and memory etc. So making the OS componentizable (or, at least, provide a way to install additional components) would be a great way to let developers pick the parts of the system they need to develop their solution, knowing that they will integrate well together. I can understand that the Arduino and Raspberry Pi* success may have attracted the attention of marketing departments worldwide and almost any new development board those days is promoted as "XXX response to Arduino" or "YYYY alternative to Raspberry Pi", but this is misleading and prevents companies from focusing on how to deliver good products and how to integrate "IoT" features with their existing offer to provide, at the end, a better product or service to their customers. Marketing is important, but can't decide the key features of a product (the OS) that is going to be used to develop full products for end customers integrating it with hardware and application software. I really like the "hackable" nature of open-source devices and like to see that companies are getting more and more open in releasing information, providing "hackable" devices and supporting developers with documentation, good samples etc. On the other side being able to run a sketch designed for an 8 bit microcontroller on a full-featured application processor may sound cool and an easy upgrade path for people that just experimented with sensors etc. on Arduino but it's not, in my humble opinion, the main path to follow for people who want to deliver real products.   *Shameless self-promotion: if you are looking for a good book in Italian about the Raspberry Pi , try mine: http://www.amazon.it/Raspberry-Pi-alluso-Digital-LifeStyle-ebook/dp/B00GYY3OKO

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  • When is my View too smart?

    - by Kyle Burns
    In this posting, I will discuss the motivation behind keeping View code as thin as possible when using patterns such as MVC, MVVM, and MVP.  Once the motivation is identified, I will examine some ways to determine whether a View contains logic that belongs in another part of the application.  While the concepts that I will discuss are applicable to most any pattern which favors a thin View, any concrete examples that I present will center on ASP.NET MVC. Design patterns that include a Model, a View, and other components such as a Controller, ViewModel, or Presenter are not new to application development.  These patterns have, in fact, been around since the early days of building applications with graphical interfaces.  The reason that these patterns emerged is simple – the code running closest to the user tends to be littered with logic and library calls that center around implementation details of showing and manipulating user interface widgets and when this type of code is interspersed with application domain logic it becomes difficult to understand and much more difficult to adequately test.  By removing domain logic from the View, we ensure that the View has a single responsibility of drawing the screen which, in turn, makes our application easier to understand and maintain. I was recently asked to take a look at an ASP.NET MVC View because the developer reviewing it thought that it possibly had too much going on in the view.  I looked at the .CSHTML file and the first thing that occurred to me was that it began with 40 lines of code declaring member variables and performing the necessary calculations to populate these variables, which were later either output directly to the page or used to control some conditional rendering action (such as adding a class name to an HTML element or not rendering another element at all).  This exhibited both of what I consider the primary heuristics (or code smells) indicating that the View is too smart: Member variables – in general, variables in View code are an indication that the Model to which the View is being bound is not sufficient for the needs of the View and that the View has had to augment that Model.  Notable exceptions to this guideline include variables used to hold information specifically related to rendering (such as a dynamically determined CSS class name or the depth within a recursive structure for indentation purposes) and variables which are used to facilitate looping through collections while binding. Arithmetic – as with member variables, the presence of arithmetic operators within View code are an indication that the Model servicing the View is insufficient for its needs.  For example, if the Model represents a line item in a sales order, it might seem perfectly natural to “normalize” the Model by storing the quantity and unit price in the Model and multiply these within the View to show the line total.  While this does seem natural, it introduces a business rule to the View code and makes it impossible to test that the rounding of the result meets the requirement of the business without executing the View.  Within View code, arithmetic should only be used for activities such as incrementing loop counters and calculating element widths. In addition to the two characteristics of a “Smart View” that I’ve discussed already, this View also exhibited another heuristic that commonly indicates to me the need to refactor a View and make it a bit less smart.  That characteristic is the existence of Boolean logic that either does not work directly with properties of the Model or works with too many properties of the Model.  Consider the following code and consider how logic that does not work directly with properties of the Model is just another form of the “member variable” heuristic covered earlier: @if(DateTime.Now.Hour < 12) {     <div>Good Morning!</div> } else {     <div>Greetings</div> } This code performs business logic to determine whether it is morning.  A possible refactoring would be to add an IsMorning property to the Model, but in this particular case there is enough similarity between the branches that the entire branching structure could be collapsed by adding a Greeting property to the Model and using it similarly to the following: <div>@Model.Greeting</div> Now let’s look at some complex logic around multiple Model properties: @if (ModelPageNumber + Model.NumbersToDisplay == Model.PageCount         || (Model.PageCount != Model.CurrentPage             && !Model.DisplayValues.Contains(Model.PageCount))) {     <div>There's more to see!</div> } In this scenario, not only is the View code difficult to read (you shouldn’t have to play “human compiler” to determine the purpose of the code), but it also complex enough to be at risk for logical errors that cannot be detected without executing the View.  Conditional logic that requires more than a single logical operator should be looked at more closely to determine whether the condition should be evaluated elsewhere and exposed as a single property of the Model.  Moving the logic above outside of the View and exposing a new Model property would simplify the View code to: @if(Model.HasMoreToSee) {     <div>There’s more to see!</div> } In this posting I have briefly discussed some of the more prominent heuristics that indicate a need to push code from the View into other pieces of the application.  You should now be able to recognize these symptoms when building or maintaining Views (or the Models that support them) in your applications.

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  • Pace Layering Comes Alive

    - by Tanu Sood
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} 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";} Rick Beers is Senior Director of Product Management for Oracle Fusion Middleware. Prior to joining Oracle, Rick held a variety of executive operational positions at Corning, Inc. and Bausch & Lomb. With a professional background that includes senior management positions in manufacturing, supply chain and information technology, Rick brings a unique set of experiences to cover the impact that technology can have on business models, processes and organizations. Rick hosts the IT Leaders Editorial on a monthly basis. By now, readers of this column are quite familiar with Oracle AppAdvantage, a unified framework of middleware technologies, infrastructure and applications utilizing a pace layered approach to enterprise systems platforms. 1. Standardize and Consolidate core Enterprise Applications by removing invasive customizations, costly workarounds and the complexity that multiple instances creates. 2. Move business specific processes and applications to the Differentiate Layer, thus creating greater business agility with process extensions and best of breed applications managed by cross- application process orchestration. 3. The Innovate Layer contains all the business capabilities required for engagement, collaboration and intuitive decision making. This is the layer where innovation will occur, as people engage one another in a secure yet open and informed way. 4. Simplify IT by minimizing complexity, improving performance and lowering cost with secure, reliable and managed systems across the entire Enterprise. But what hasn’t been discussed is the pace layered architecture that Oracle AppAdvantage adopts. What is it, what are its origins and why is it relevant to enterprise scale applications and technologies? It’s actually a fascinating tale that spans the past 20 years and a basic understanding of it provides a wonderful context to what is evolving as the future of enterprise systems platforms. It all begins in 1994 with a book by noted architect Stewart Brand, of ’Whole Earth Catalog’ fame. In his 1994 book How Buildings Learn, Brand popularized the term ‘Shearing Layers’, arguing that any building is actually a hierarchy of pieces, each of which inherently changes at different rates. In 1997 he produced a 6 part BBC Series adapted from the book, in which Part 6 focuses on Shearing Layers. In this segment Brand begins to introduce the concept of ‘pace’. Brand further refined this idea in his subsequent book, The Clock of the Long Now, which began to link the concept of Shearing Layers to computing and introduced the term ‘pace layering’, where he proposes that: “An imperative emerges: an adaptive [system] has to allow slippage between the differently-paced systems … otherwise the slow systems block the flow of the quick ones and the quick ones tear up the slow ones with their constant change. Embedding the systems together may look efficient at first but over time it is the opposite and destructive as well.” In 2000, IBM architects Ian Simmonds and David Ing published a paper entitled A Shearing Layers Approach to Information Systems Development, which applied the concept of Shearing Layers to systems design and development. It argued that at the time systems were still too rigid; that they constrained organizations by their inability to adapt to changes. The findings in the Conclusions section are particularly striking: “Our starting motivation was that enterprises need to become more adaptive, and that an aspect of doing that is having adaptable computer systems. The challenge is then to optimize information systems development for change (high maintenance) rather than stability (low maintenance). Our response is to make it explicit within software engineering the notion of shearing layers, and explore it as the principle that systems should be built to be adaptable in response to the qualitatively different rates of change to which they will be subjected. This allows us to separate functions that should legitimately change relatively slowly and at significant cost from that which should be changeable often, quickly and cheaply.” The problem at the time of course was that this vision of adaptable systems was simply not possible within the confines of 1st generation ERP, which were conceived, designed and developed for standardization and compliance. It wasn’t until the maturity of open, standards based integration, and the middleware innovation that followed, that pace layering became an achievable goal. And Oracle is leading the way. Oracle’s AppAdvantage framework makes pace layering come alive by taking a strategic vision 20 years in the making and transforming it to a reality. It allows enterprises to retain and even optimize their existing ERP systems, while wrapping around those ERP systems three layers of capabilities that inherently adapt as needed, at a pace that’s optimal for the enterprise.

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  • How to handle updated configuration when it's already been cloned for editing

    - by alexrussell
    Really sorry about the title that probably doesn't make much sense. Hopefully I can explain myself better here as it's something that's kinda bugged me for ages, and is now becoming a pressing concern as I write a bit of software with configuration. Most software comes with default configuration options stored in the app itself, and then there's a configuration file (let's say) that a user can edit. Once created/edited for the first time, subsequent updates to the application can not (easily) modify this configuration file for fear of clobbering the user's own changes to the default configuration. So my question is, if my application adds a new configurable parameter, what's the best way to aid discoverability of the setting and allow the user (developer) to override it as nicely as possible given the following constraints: I actually don't have a canonical default config in the application per se, it's more of a 'cascading filesystem'-like affair - the config template is stored in default/config.json and when the user wishes to edit the configuration, it's copied to user/config.json. If a user config is found it is used - there is no automatic overriding of a subset of keys, the whole new file is used and that's that. If there's no user config the default config is used. When a user wishes to edit the config they run a command to 'generate' it for them (which simply copies the config.json file from the default to the user directory). There is no UI for the configuration options as it's not appropriate to the userbase (think of my software as a library or something, the users are developers, the config is done in the user/config.json file). Due to my software being library-like there's no simple way to, on updating of the software, run some tasks automatically (so any ideas of look at the current config, compare to template config, add ing missing keys) aren't appropriate. The only solution I can think of right now is to say "there's a new config setting X" in release notes, but this doesn't seem ideal to me. If you want any more information let me know. The above specifics are not actually 100% true to my situation, but they represent the problem equally well with lower complexity. If you do want specifics, however, I can explain the exact setup. Further clarification of the type of configuration I mean: think of the Atom code editor. There appears to be a default 'template' config file somewhere, but as soon as a configuration option is edited ~/.atom/config.cson is generated and the setting goes in there. From now on is Atom is updated and gets a new configuration key, this file cannot be overwritten by Atom without a lot of effort to ensure that the addition/modification of the key does not clobber. In Atom's case, because there is a GUI for editing settings, they can get away with just adding the UI for the new setting into the UI to aid 'discoverability' of the new setting. I don't have that luxury. Clarification of my constraints and what I'm actually looking for: The software I'm writing is actually a package for a larger system. This larger system is what provides the configuration, and the way it works is kinda fixed - I just do a config('some.key') kinda call and it knows to look to see if the user has a config clone and if so use it, otherwise use the default config which is part of my package. Now, while I could make my application edit the user's configuration files (there is a convention about where they're stored), it's generally not done, so I'd like to live with the constraints of the system I'm using if possible. And it's not just about discoverability either, one large concern is that the addition of a configuration key won't actually work as soon as the user has their own copy of the original template. Adding the key to the template won't make a difference as that file is never read. As such, I think this is actually quite a big flaw in the design of the configuration cascading system and thus needs to be taken up with my upstream. So, thinking about it, based on my constraints, I don't think there's going to be a good solution save for either editing the user's configuration or using a new config file every time there are updates to the default configuration. Even the release notes idea from above isn't doable as, if the user does not follow the advice, suddenly I have a config key with no value (user-defined or default). So the new question is this: what is the general way to solve the problem of having a default configuration in template config files and allowing a user to make user-specific version of these in order to override the defaults? A per-key cascade (rather than per-file cascade) where the user only specifies their overrides? In this case, what happens if a configuration value is an array - do we replace or append to the default (or, more realistically, how does the user specify whether they wish to replace or append to)? It seems like configuration is kinda hard, so how is it solved in the wild?

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  • Creating ADF Faces Comamnd Button at Runtime

    - by Frank Nimphius
    Normal 0 false false false EN-US X-NONE X-NONE /* 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:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} In ADF Faces, the command button is an instance of RichCommandButton and can be created at runtime. While creating the button is not difficult at all, adding behavior to it requires knowing about how to dynamically create and add an action listener reference. The example code below shows two methods: The first method, handleButtonPress is a public method exposed on a managed bean. public void handleButtonPress(ActionEvent event){   System.out.println("Event handled");   //optional: partially refresh changed components if command   //issued as a partial submit } The second method is called in response to a user interaction or on page load and dynamically creates and adds a command button. When the button is pressed, the managed bean method – the action handler – defined above is called. The action handler is referenced using EL in the created MethodExpression instance. If the managed bean is in viewScope, backingBeanScope or pageFlowsScope, then you need to add these scopes as a prefix to the EL (as you would when configuring the managed bean reference at design time) //Create command button and add it as a child to the parent component that is passed as an //argument to this method private void reateCommandButton(UIComponent parent){   RichCommandButton edit = new RichCommandButton();   //make the request partial   edit.setPartialSubmit(true);   edit.setText("Edit");                             //compose the method expression to invoke the event handler   FacesContext fctx = FacesContext.getCurrentInstance();   Application application = fctx.getApplication();   ExpressionFactory elFactory = application.getExpressionFactory();   ELContext elContext = facesCtx.getELContext();   MethodExpression methodExpressio = null;   //Make sure the EL expression references a valid managed bean method. Ensure   //the bean scope is properly addressed    methodExpression =  elFactory.createMethodExpression(                              elContext,"#{myRequestScopeBean.handleButtonPress}",                             Object.class,new Class[] {ActionEvent.class});   //Create the command buttonaction listener reference   MethodExpressionActionListener al = null;          al= new MethodExpressionActionListener(methodExpression);    edit.addActionListener(al);     //add new command button to parent component and PPR the component for     //the button to show    parent.getChildren().add(edit);    AdfFacesContext adfFacesContext = AdfFacesContext.getCurrentInstance();     adfFacesContext.addPartialTarget(parent);  }

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  • Migrating Core Data to new UIManagedDocument in iOS 5

    - by samerpaul
    I have an app that has been on the store since iOS 3.1, so there is a large install base out there that still uses Core Data loaded up in my AppDelegate. In the most recent set of updates, I raised the minimum version to 4.3 but still kept the same way of loading the data. Recently, I decided it's time to make the minimum version 5.1 (especially with 6 around the corner), so I wanted to start using the new fancy UIManagedDocument way of using Core Data. The issue with this though is that the old database file is still sitting in the iOS app, so there is no migrating to the new document. You have to basically subclass UIManagedDocument with a new model class, and override a couple of methods to do it for you. Here's a tutorial on what I did for my app TimeTag.  Step One: Add a new class file in Xcode and subclass "UIManagedDocument" Go ahead and also add a method to get the managedObjectModel out of this class. It should look like:   @interface TimeTagModel : UIManagedDocument   - (NSManagedObjectModel *)managedObjectModel;   @end   Step two: Writing the methods in the implementation file (.m) I first added a shortcut method for the applicationsDocumentDirectory, which returns the URL of the app directory.  - (NSURL *)applicationDocumentsDirectory {     return [[[NSFileManagerdefaultManager] URLsForDirectory:NSDocumentDirectoryinDomains:NSUserDomainMask] lastObject]; }   The next step was to pull the managedObjectModel file itself (.momd file). In my project, it's called "minimalTime". - (NSManagedObjectModel *)managedObjectModel {     NSString *path = [[NSBundlemainBundle] pathForResource:@"minimalTime"ofType:@"momd"];     NSURL *momURL = [NSURL fileURLWithPath:path];     NSManagedObjectModel *managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:momURL];          return managedObjectModel; }   After that, I need to check for a legacy installation and migrate it to the new UIManagedDocument file instead. This is the overridden method: - (BOOL)configurePersistentStoreCoordinatorForURL:(NSURL *)storeURL ofType:(NSString *)fileType modelConfiguration:(NSString *)configuration storeOptions:(NSDictionary *)storeOptions error:(NSError **)error {     // If legacy store exists, copy it to the new location     NSURL *legacyPersistentStoreURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"minimalTime.sqlite"];          NSFileManager* fileManager = [NSFileManagerdefaultManager];     if ([fileManager fileExistsAtPath:legacyPersistentStoreURL.path])     {         NSLog(@"Old db exists");         NSError* thisError = nil;         [fileManager replaceItemAtURL:storeURL withItemAtURL:legacyPersistentStoreURL backupItemName:niloptions:NSFileManagerItemReplacementUsingNewMetadataOnlyresultingItemURL:nilerror:&thisError];     }          return [superconfigurePersistentStoreCoordinatorForURL:storeURL ofType:fileType modelConfiguration:configuration storeOptions:storeOptions error:error]; }   Basically what's happening above is that it checks for the minimalTime.sqlite file inside the app's bundle on the iOS device.  If the file exists, it tells you inside the console, and then tells the fileManager to replace the storeURL (inside the method parameter) with the legacy URL. This basically gives your app access to all the existing data the user has generated (otherwise they would load into a blank app, which would be disastrous). It returns a YES if successful (by calling it's [super] method). Final step: Actually load this database Due to how my app works, I actually have to load the database at launch (instead of shortly after, which would be ideal). I call a method called loadDatabase, which looks like this: -(void)loadDatabase {     static dispatch_once_t onceToken;          // Only do this once!     dispatch_once(&onceToken, ^{         // Get the URL         // The minimalTimeDB name is just something I call it         NSURL *url = [[selfapplicationDocumentsDirectory] URLByAppendingPathComponent:@"minimalTimeDB"];         // Init the TimeTagModel (our custom class we wrote above) with the URL         self.timeTagDB = [[TimeTagModel alloc] initWithFileURL:url];           // Setup the undo manager if it's nil         if (self.timeTagDB.undoManager == nil){             NSUndoManager *undoManager = [[NSUndoManager  alloc] init];             [self.timeTagDB setUndoManager:undoManager];         }                  // You have to actually check to see if it exists already (for some reason you can't just call "open it, and if it's not there, create it")         if ([[NSFileManagerdefaultManager] fileExistsAtPath:[url path]]) {             // If it does exist, try to open it, and if it doesn't open, let the user (or at least you) know!             [self.timeTagDB openWithCompletionHandler:^(BOOL success){                 if (!success) {                     // Handle the error.                     NSLog(@"Error opening up the database");                 }                 else{                     NSLog(@"Opened the file--it already existed");                     [self refreshData];                 }             }];         }         else {             // If it doesn't exist, you need to attempt to create it             [self.timeTagDBsaveToURL:url forSaveOperation:UIDocumentSaveForCreatingcompletionHandler:^(BOOL success){                 if (!success) {                     // Handle the error.                     NSLog(@"Error opening up the database");                 }                 else{                     NSLog(@"Created the file--it did not exist");                     [self refreshData];                 }             }];         }     }); }   If you're curious what refreshData looks like, it sends out a NSNotification that the database has been loaded: -(void)refreshData {     NSNotification* refreshNotification = [NSNotificationnotificationWithName:kNotificationCenterRefreshAllDatabaseData object:self.timeTagDB.managedObjectContext  userInfo:nil];     [[NSNotificationCenter defaultCenter] postNotification:refreshNotification];     }   The kNotificationCenterRefreshAllDatabaseData is just a constant I have defined elsewhere that keeps track of all the NSNotification names I use. I pass the managedObjectContext of the newly created file so that my view controllers can have access to it, and start passing it around to one another. The reason we do this as a Notification is because this is being run in the background, so we can't know exactly when it finishes. Make sure you design your app for this! Have some kind of loading indicator, or make sure your user can't attempt to create a record before the database actually exists, because it will crash the app.

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