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• OracleServiceBus+SOA in same server

  - by Manoj Neelapu

  Oracle Service Bus 11gR1 (11.1.1.3) supports running in same JVM as SOA. This tutorial covers on how to do create domain in of SOA+OSB combined to run in single JVM .For this tutorial we will use a flavor  WebLogic installer bundled with both OEPE and coherence components (eg oepe111150_wls1033_win32.exe). WebLogic installer bundled with coherence and OEPE components can be seen in the screen shot.Oracle Service Bus 11gR1 (11.1.1.3) has built-in caching support for Business Services using coherence. Because of this we will have to install coherence before  installing OSB.  To get SOAand OSB running in the same domain, we have to install the SOA and OSB on the above ORACLE_HOME. After installation we should see both the SOA and OSB homes has highlighted in red.We could also see the coherence components which is mandatory for OSB and optional OEPE also installed.                     Now we will execute RCU(ofm_rcu_win_11.1.1.3.0_disk1_1of1) to install the schema for SOA and OSB. New RCU contains OSB tables (WLI_QS_REPORT_DATA , WLI_QS_REPORT_ATTRIBUTE) gets loaded as part of SOAINFRA schema  After this step we will have to create soa+osb domain using config wizard. It is located under $WEBLOGIC_HOME\common\bin\config.* (.cmd or .sh as per your platform) .While creating a domain we will select options for SOA Suite  and Oracle Service Bus Extension-All Domain Topologies.We can also bundle Enterprise Manager in the same installation or in a different server. Here in this case we will use the enterprise manager in the same domain. So we selected the Enterprise Manager component also. There is another option for OSB  Oracle Service Bus Extension-Single server Domain Topology. This topology is for users who want to use OSB in single server configuration. Currently SOA doesn't support single server topology. So this topology cannot be used with SOA domain but can only be used for stand alone OSB installations.We can continue with domain configuration till we reach the below screen. Following steps are mandatory if we want to have the SOA and OSB run in same JVMwe should select Managed Server, Clusters and Machines as shown below   After this selection you should see a screen with two servers One managed server for OSB and one managed for SOA.  Since we would like to have both the servers in one managed server (one JVM) we will have to do one  

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• Inverted schedctl usage in the JVM

  - by Dave

  The schedctl facility in Solaris allows a thread to request that the kernel defer involuntary preemption for a brief period. The mechanism is strictly advisory - the kernel can opt to ignore the request. Schedctl is typically used to bracket lock critical sections. That, in turn, can avoid convoying -- threads piling up on a critical section behind a preempted lock-holder -- and other lock-related performance pathologies. If you're interested see the man pages for schedctl_start() and schedctl_stop() and the schedctl.h include file. The implementation is very efficient. schedctl_start(), which asks that preemption be deferred, simply stores into a thread-specific structure -- the schedctl block -- that the kernel maps into user-space. Similarly, schedctl_stop() clears the flag set by schedctl_stop() and then checks a "preemption pending" flag in the block. Normally, this will be false, but if set schedctl_stop() will yield to politely grant the CPU to other threads. Note that you can't abuse this facility for long-term preemption avoidance as the deferral is brief. If your thread exceeds the grace period the kernel will preempt it and transiently degrade its effective scheduling priority. Further reading : US05937187 and various papers by Andy Tucker. We'll now switch topics to the implementation of the "synchronized" locking construct in the HotSpot JVM. If a lock is contended then on multiprocessor systems we'll spin briefly to try to avoid context switching. Context switching is wasted work and inflicts various cache and TLB penalties on the threads involved. If context switching were "free" then we'd never spin to avoid switching, but that's not the case. We use an adaptive spin-then-park strategy. One potentially undesirable outcome is that we can be preempted while spinning. When our spinning thread is finally rescheduled the lock may or may not be available. If not, we'll spin and then potentially park (block) again, thus suffering a 2nd context switch. Recall that the reason we spin is to avoid context switching. To avoid this scenario I've found it useful to enable schedctl to request deferral while spinning. But while spinning I've arranged for the code to periodically check or poll the "preemption pending" flag. If that's found set we simply abandon our spinning attempt and park immediately. This avoids the double context-switch scenario above. One annoyance is that the schedctl blocks for the threads in a given process are tightly packed on special pages mapped from kernel space into user-land. As such, writes to the schedctl blocks can cause false sharing on other adjacent blocks. Hopefully the kernel folks will make changes to avoid this by padding and aligning the blocks to ensure that one cache line underlies at most one schedctl block at any one time.

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• SQL SERVER – CSVExpress and Quick Data Load

  - by pinaldave

  One of the newest ETL tools is CSVexpress.com.  This is a program that can quickly load any CSV file into ODBC compliant databases uses data integration.  For those of you familiar with databases and how they operate, the question that comes to mind might be what use this program will have in your life. I have written earlier article on this subject over here SQL SERVER – Import CSV into Database – Transferring File Content into a Database Table using CSVexpress. You might know that RDBMS have automatic support for loading CSV files into tables – but it is not quite as easy as one click of a button.  First of all, most databases have a command line interface and you need the file and configuration script in order to load up.  You also need to know enough to write the script – which for novices can be extremely daunting.  On top of all this, if you work with more than one type of RDBMS, you need to know the ins and outs of uploading and writing script for more than one program. So you might begin to see how useful CSVexpress.com might be!  There are many other tools that enable uploading files to a database.  They can be very fancy – some can generate configuration files automatically, others load the data directly.  Again, novices will be able to tell you why these aren’t the most useful programs in the world.  You see, these programs were created with SQL in mind, not for uploading data.  If you don’t have large amounts of data to upload, getting the configurations right can be a long process and you will have to check the code that is generated yourself.  Not exactly “easy to use” for novices. That makes CSVexpress.com one of the best new tools available for everyone – but especially people who don’t want to learn a lot of new material all at once.  CSVexpress has an easy to navigate graphical user interface and no scripting or coding is required.  There are built-in constraints and data validations, and you can configure transforms and reject records right there on the screen.  But the best thing of all – it’s free! That’s right, you can download CSVexpress for free from www.csvexpress.com and start easily uploading and configuring riles almost immediately.  If you’re currently happy with your method of data configuration, keep up with the good work.  For the rest of us, there’s CSVexpress.com. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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• ArchBeat Link-o-Rama for 2012-07-10

  - by Bob Rhubart

  Free Event Today: Virtual Developer Day: Oracle Fusion Development This free event—another in the ongoing series of OTN Virtual Developer Days—focuses on Oracle Fusion development, and features three session tracks plus hands-on labs. Agenda and session abstracts are available now so you can be ready for the live event when it kicks off today, July 10, 9am to 1pm PST / 12pm to 4pm EST / 1pm to 5pm BRT. Podcast: The Role of the Cloud Architect - Part 1/3 In part one of this three-part conversation, cloud architects Ron Batra (AT&T) and James Baty (Oracle) talk about how cloud computing is driving the supply-chaining of IT and the "democratization of the activity of architecture." Middleware and Cloud Computing Book | Tom Laszewski Cloud migration expert Tom Laszewski describes Middleware and Cloud Computing by Frank Munz as "one of only a couple books that really discuss AWS and Oracle in depth." Cloud computing moves from fad to foundation | David Linthicum "When enterprises make cloud computing work, they view the application of the technology as a trade secret of sorts, so there are no press releases or white papers," says David Linthicum. "Indeed, if you see one presentation around a successful cloud computing case study, you can bet you're not hearing about 100 more." Oracle Real-Time Decisions: Combined Likelihood Models | Lukas Vermeer Lukas Vermeer concludes his extensive series of posts on decision models with a look "an advanced approach to amalgamate models, taking us to a whole new level of predictive modeling and analytical insights; combination models predicting likelihoods using multiple child models." Running Oracle BPM 11g PS5 Worklist Task Flow and Human Task Form on Non-SOA Domain | Andrejus Baranovskis "With a standard setup, both the BPM worklist application and the Human task form run on the same SOA domain, where the BPM process is running," says Oracle ACE Director Andrejus Baranovskis. "While this work fine, this is not what we want in the development, test and production environment." BAM design pointers | Kavitha Srinivasan "When using EMS (Enterprise Message Source) as a BAM feed, the best practice is to use one EMS to write to one Data Object," says Oracle Fusion Middleware A-Team blogger Kavitha Srinivasan. "There is a possibility of collisions and duplicates when multiple EMS write to the same row of a DO at the same time." Changes in SOA Human Task Flow (Run-Time) for Fusion Applications | Jack Desai Oracle Fusion Middleware A-Team blogger Jack Desai shares a troubleshooting tip. Thought for the Day "A program which perfectly meets a lousy specification is a lousy program." — Cem Kaner Source: SoftwareQuotes.com

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• Top 5 Sites and Activities in San Francisco to Experience During Oracle OpenWorld

  - by kgee

  While Oracle OpenWorld may provide solutions and information on topics like how to simplify your IT, the importance of cloud, and what types of storage may satisfy your enterprise needs, who is going to tell you more about San Francisco? Here are some suggested sites and activities to experience after OpenWorld that aren’t too far from the Moscone Center. It is recommended to take a cab for the sake of time, but the 6 square miles that make up San Francisco will make for a quick trek to any of the following destinations: The Golden Gate BridgeAn image often associated with San Francisco, this bridge is one of the most impressive in the world. Take a walk across it, or view it from nearby Crissy Field, it is a sight that floors even the most veteran of San Franciscans. The Ferry BuildingLocated at the end of Market Street in the Embarcadero, the Ferry Building once served as a hub of water transport and trade. The building has a bay front view and an array of food choices and restaurants. It is easily accessible via the Muni, BART, trolley or by cab. It is a must-see in San Francisco, and not too far from the Moscone Center. Ride the Trolley to the CastroFor only $2, you can get go back in history for a moment on the Trolley. Take the F-line from the Embarcadero and ride it all the way to the Castro district. During the ride, you will get an overview of the landscape and cultures that are prevalent in San Francisco, but be wary that some areas may beg for an open mind more than others. Golden Gate ParkWhen you tire of the concrete jungle, the lucky part of being in San Francisco is that you can escape to a natural refuge, this park being one of the favorites. This park is known for its hiking trails, cultural attractions, monuments, lakes and gardens. It is one good reason to bring your sneakers to San Francisco, and is also a great place to picnic. Please be wary that it is easy to get lost, and it is advisable to bring a map (just in case) if you go. Haight AshburyFor a complete change of scenery, Haight Ashbury is known as one of the places hippies used to live and the location of "The Summer of Love." It is now a more affluent neighborhood with boutique shops and the occasional drum circle. While it may be perceived as grungy in certain spots, it is one of the most photographed places in San Francisco and an integral part of San Franciscan history.

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• Book Review (Book 11) - Applied Architecture Patterns on the Microsoft Platform

  - by BuckWoody

  This is a continuation of the books I challenged myself to read to help my career - one a month, for year. You can read my first book review here, and the entire list is here. The book I chose for April 2012 was: Applied Architecture Patterns on the Microsoft Platform. I was traveling at the end of last month so I’m a bit late posting this review here. Why I chose this book: I actually know a few of the authors on this book, so when they told me about it I wanted to check it out. The premise of the book is exactly as it states in the title - to learn how to solve a problem using products from Microsoft. What I learned: I liked the book - a lot. They've arranged the content in a "Solution Decision Framework", that presents a few elements to help you identify a need and then propose alternate solutions to solve them, and then the rationale for the choice. But the payoff is that the authors then walk through the solution they implement and what they ran into doing it. I really liked this approach. It's not a huge book, but one I've referred to again since I've read it. It's fairly comprehensive, and includes server-oriented products, not things like Microsoft Office or other client-side tools. In fact, I would LOVE to have a work like this for Open Source and other vendors as well - would make for a great library for a Systems Architect. This one is unashamedly aimed at the Microsoft products, and even if I didn't work here, I'd be fine with that. As I said, it would be interesting to see some books on other platforms like this, but I haven't run across something that presents other systems in quite this way. And that brings up an interesting point - This book is aimed at folks who create solutions within an organization. It's not aimed at Administrators, DBA's, Developers or the like, although I think all of those audiences could benefit from reading it. The solutions are made up, and not to a huge level of depth - nor should they be. It's a great exercise in thinking these kinds of things through in a structured way. The information is a bit dated, especially for Windows and SQL Azure. While the general concepts hold, the cloud platform from Microsoft is evolving so quickly that any printed book finds it hard to keep up with the improvements. I do have one quibble with the text - the chapters are a bit uneven. This is always a danger with multiple authors, but it shows up in a couple of chapters. I winced at one of the chapters that tried to take a more conversational, humorous style. This kind of academic work doesn't lend itself to that style. I recommend you get the book - and use it. I hope they keep it updated - I'll be a frequent customer. :)  

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• A Community Cure for a String Splitting Headache

  - by Tony Davis

  A heartwarming tale of dogged perseverance and Community collaboration to solve some SQL Server string-related headaches. Michael J Swart posted a blog this week that had me smiling in recognition and agreement, describing how an inquisitive Developer or DBA deals with a problem. It's a three-step process, starting with discomfort and anxiety; a feeling that one doesn't know as much about one's chosen specialized subject as previously thought. It progresses through a phase of intense research and learning until finally one achieves breakthrough, blessed relief and renewed optimism. In this case, the discomfort was provoked by the mystery of massively high CPU when searching Unicode strings in SQL Server. Michael explored the problem via Stack Overflow, Google and Twitter #sqlhelp, finally leading to resolution and a blog post that shared what he learned. Perfect; except that sometimes you have to be prepared to share what you've learned so far, while still mired in the phase of nagging discomfort. A good recent example of this recently can be found on our own blogs. Despite being a loud advocate of the lightning fast T-SQL-based string splitting techniques, honed to near perfection over many years by Jeff Moden and others, Phil Factor retained a dogged conviction that, in theory, shredding element-based XML using XQuery ought to be even more efficient for splitting a string to create a table. After some careful testing, he found instead that the XML way performed and scaled miserably by comparison. Somewhat subdued, and with a nagging feeling that perhaps he was still missing "something", he posted his findings. What happened next was a joy to behold; the community jumped in to suggest subtle changes in approach, using an attribute-based rather than element-based XML list, and tweaking the XQuery shredding. The result was performance and scalability that surpassed all other techniques. I asked Phil how quickly he would have arrived at the real breakthrough on his own. His candid answer was "never". Both are great examples of the power of Community learning and the latter in particular the importance of being brave enough to parade one's ignorance. Perhaps Jeff Moden will accept the string-splitting gauntlet one more time. To quote the great man: you've just got to love this community! If you've an interesting tale to tell about being helped to a significant breakthrough for a problem by the community, I'd love to hear about it. Cheers, Tony.

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• "Well, Swing took a bit of a beating this week..."

  - by Geertjan

  One unique aspect of the NetBeans community presence at JavaOne 2012 was its usage of large panels to highlight and discuss various aspects (e.g., Java EE, JavaFX, etc) of NetBeans IDE usage and tools. For example, here's a pic of one of the panels, taken by Markus Eisele: Above you see me, Sean Comerford from ESPN.com, Gerrick Bivins from Halliburton, Angelo D'Agnano and Ioannis Kostaras from the NATO Programming Center, and Çagatay Çivici from PrimeFaces. (And Tinu Awopetu was also on the panel but not in the picture!) On one of those panels a remark was made which has kind of stuck with me. Henry Arousell, a member of the "NetBeans Platform Discussion Panel", who works on accounting software in Sweden, together with Thomas Boqvist, who was also at JavaOne, said, a bit despondently, I thought, the following words at the start of the demo of his very professional looking accounting software: "Well, Swing took a bit of a beating this week..." That remark comes in the light of several JavaFX sessions held at JavaOne, together with many sessions from the web and mobile worlds making the argument that the browser, tablet, and mobile platforms are the future of all applications everywhere. However, then I had another look at the list of Duke's Choice Award winners: http://www.oracle.com/us/corporate/press/1854931 OK, there are 10 winners of the Duke's Choice Award this year. Three of them (JDuchess, London Java Community, Student Nokia Developer Group) are not awards for software, but for people or groups. So, that leaves seven awards. Three of them (Hadoop, Jelastic, and Parleys) are, in one way or another, some kind of web-oriented solution, though both Hadoop and Jelastic are broader than that, but are service-oriented solutions, relating to cloud technologies. That leaves four others: NATO air defense software, Liquid Robotics software, AgroSense software, and UNHCR Refugee Registration software. All these are, on the software level, Java desktop solutions that, on the UI layer, make use of Java Swing, together with LuciadMaps (NATO), GeoToolkit (AgroSense), and WorldWind (Liquid Robotics). (And, it went even further than that, i.e., this is not passive usage of Swing but active and motivated: Timon Veenstra, during his AgroSense demo, said "There are far more Swing applications out there than we seem to think. Web developers just make more noise." And, during his Liquid Robotics demo, James Gosling said: "Not everything can be done in HTML.") Seems to me that Java Swing was the enabler of more Duke's Choice Award winners this year than any other UI-oriented Java technology. Now, I'm not going to interpret that one way or another, since I've noticed that interpretations of facts tend to validate some underlying agenda. Take any fact anywhere and you can interpret it to prove whatever opinion you're already holding to be true. Therefore, no interpretation from me. Simply stating the fact that Swing, far from taking a beating during JavaOne 2012, was a more significant user interface enabler of Duke's Choice Award winners than any other Java user interface technology. That's not an interpretation, but a fact.

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• Oracle's Integrated Systems Management and Support Experience

  - by Scott McNeil

  With its recent launch, Oracle Enterprise Manager 11g introduced a new approach to integrated systems management and support. What this means is taking both areas of IT management and vendor support and combining them into one integrated comprehensive and centralized platform. Traditional Ways Under the traditional method, IT operational teams would often focus on running their systems using management tools that weren’t connected to their vendor’s support systems. If you needed support with a product, administrators would often contact the vendor by phone or visit the vendor website for support and then log a service request in order to fix the issues. This method was also very time consuming, as administrators would have to collect their software configurations, operating systems and hardware settings, then manually enter them into an online form or recite them to a support analyst on the phone. For the vendor, they had to analyze all the configuration data to recreate the problem in order to solve it. This approach was very manual, uncoordinated and error-prone where duplication between the customer and vendor frequently occurred. A Better Support Experience By removing the boundaries between support, IT management tools and the customer’s IT infrastructure, Oracle paved the way for a better support experience. This was achieved through integration between Oracle Enterprise Manager 11g and My Oracle Support. Administrators can not only manage their IT infrastructure and applications through Oracle Enterprise Manager’s centralized console but can also receive proactive alerts and patch recommendations right within the console they use day-in-day-out. Having one single source of information saves time and potentially prevents unforeseen problems down the road. All for One, and One for All The first step for you is to allow Oracle Enterprise Manager to upload configuration data into Oracle’s secure configuration repository, where it can be analyzed for potential issues or conflicts for all customers. A fix to a problem encountered by one customer may actually be relevant to many more. The integration between My Oracle Support and Oracle Enterprise Manager allows all customers who may be impacted by the problem to receive a notification about the fix. Once the alert appears in Oracle Enterprise Manager’s console, the administrator can take his/her time to do further investigations using automated workflows provided in Oracle Enterprise Manager to analyze potential conflicts. Finally, administrators can schedule a time to test and automatically apply the fix to all the systems that need it. In the end, this helps customers maintain their service levels without compromise and avoid experiencing unplanned downtime that may result from potential issues or conflicts. This new paradigm of integrated systems management and support helps customers keep their systems secure, compliant, and up-to-date, while eliminating the traditional silos between IT management and vendor support. Oracle’s next generation platform also works hand-in-hand to provide higher quality of service to business users while at the same time making life for administrators less complicated. For more information on Oracle’s integrated systems management and support experience, be sure to visit our Oracle Enterprise Manager 11g Resource Center for the latest customer videos, webcast, and white papers.

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• Lesser Known NHibernate Session Methods

  - by Ricardo Peres

  The NHibernate ISession, the core of NHibernate usage, has some methods which are quite misunderstood and underused, to name a few, Merge, Persist, Replicate and SaveOrUpdateCopy. Their purpose is: Merge: copies properties from a transient entity to an eventually loaded entity with the same id in the first level cache; if there is no loaded entity with the same id, one will be loaded and placed in the first level cache first; if using version, the transient entity must have the same version as in the database; Persist: similar to Save or SaveOrUpdate, attaches a maybe new entity to the session, but does not generate an INSERT or UPDATE immediately and thus the entity does not get a database-generated id, it will only get it at flush time; Replicate: copies an instance from one session to another session, perhaps from a different session factory; SaveOrUpdateCopy: attaches a transient entity to the session and tries to save it. Here are some samples of its use. ISession session = ...; AuthorDetails existingDetails = session.Get<AuthorDetails>(1); //loads an entity and places it in the first level cache AuthorDetails detachedDetails = new AuthorDetails { ID = existingDetails.ID, Name = "Changed Name" }; //a detached entity with the same ID as the existing one Object mergedDetails = session.Merge(detachedDetails); //merges the Name property from the detached entity into the existing one; the detached entity does not get attached session.Flush(); //saves the existingDetails entity, since it is now dirty, due to the change in the Name property AuthorDetails details = ...; ISession session = ...; session.Persist(details); //details.ID is still 0 session.Flush(); //saves the details entity now and fetches its id ISessionFactory factory1 = ...; ISessionFactory factory2 = ...; ISession session1 = factory1.OpenSession(); ISession session2 = factory2.OpenSession(); AuthorDetails existingDetails = session1.Get<AuthorDetails>(1); //loads an entity session2.Replicate(existingDetails, ReplicationMode.Overwrite); //saves it into another session, overwriting any possibly existing one with the same id; other options are Ignore, where any existing record with the same id is left untouched, Exception, where an exception is thrown if there is a record with the same id and LatestVersion, where the latest version wins SyntaxHighlighter.config.clipboardSwf = 'http://alexgorbatchev.com/pub/sh/2.0.320/scripts/clipboard.swf'; SyntaxHighlighter.brushes.CSharp.aliases = ['c#', 'c-sharp', 'csharp']; SyntaxHighlighter.all();

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

  - by pinaldave

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

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• Tales of a corrupt SQL log

  - by guybarrette

  Warning: I’m a simple dev, not an all powerful DBA with godly powers. This morning, one of my sites was down and DNN reported a problem with the database.  A quick series of tests revealed that the culprit was a corrupted log file. Easy fix I said, I have daily backups so it’s just a mater of restoring a good copy of the database and log files.  Well, I found out that’s not exactly true.  You see, for this database, I have daily file backups and these are not database backups created by SQL Server. So I restored a set of files from a couple of days ago, stopped the SQL service, copied the files over the bad ones, restarted the service only to find out that SQL doesn’t like when you do that.  It suspects something fishy and marks the database as suspect.  A database marked as suspect can’t be accessed at all.  So now what? I searched throughout the tubes of the InterWeb and found that you can restore from a corrupted log file by creating a new database with the same name as the defective one, then copy the restored database file (the one with data) over the newly created one.  Sweet!  But you still end up with SQL marking the database as suspect but at least, the newly created log is OK.  Well not true, it’s not corrupted but the lack of data makes it not OK for SQL so you need to rebuild the log.  How can you do that when SQL blocks any action the database?  First, you need to change the database status from suspect to emergency.  Then you need to set the database for single access only.  After that, you need to repair the log with DBCC and do the DBA dance.  If you dance long enough, SQL should repair the log file.  Now you need to set the access back to multi user.  Here’s the T-SQL script: use master GO EXEC sp_resetstatus 'MyDatabase' ALTER DATABASE MyDatabase SET EMERGENCY Alter database MyDatabase set Single_User DBCC checkdb('MyDatabase') ALTER DATABASE MyDatabase SET SINGLE_USER WITH ROLLBACK IMMEDIATE DBCC CheckDB ('MyDatabase', REPAIR_ALLOW_DATA_LOSS) ALTER DATABASE MyDatabase SET MULTI_USER So I guess that I would have been a lot easier to restore a SQL backup.  I can’t really say but the InterWeb seems to say so.  Anyway, lessons learned: Vive la différence: File backups are different then SQL backups. Don’t touch me: SQL doesn’t like when you restore a file over a corrupted one. The more the merrier: You should do both SQL and file backups. WTF?: The InterWeb provides you with dozens of way to deal with the problem but many are SQL 2000 or SQL 2005 only, many are confusing and many are written in strange dialects only DBAs understand. var addthis_pub="guybarrette";

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• Basis of definitions

  - by Yttrill

  Let us suppose we have a set of functions which characterise something: in the OO world methods characterising a type. In mathematics these are propositions and we have two kinds: axioms and lemmas. Axioms are assumptions, lemmas are easily derived from them. In C++ axioms are pure virtual functions. Here's the problem: there's more than one way to axiomatise a system. Given a set of propositions or methods, a subset of the propositions which is necessary and sufficient to derive all the others is called a basis. So too, for methods or functions, we have a desired set which must be defined, and typically every one has one or more definitions in terms of the others, and we require the programmer to provide instance definitions which are sufficient to allow all the others to be defined, and, if there is an overspecification, then it is consistent. Let me give an example (in Felix, Haskell code would be similar): class Eq[t] { virtual fun ==(x:t,y:t):bool => eq(x,y); virtual fun eq(x:t, y:t)=> x == y; virtual fun != (x:t,y:t):bool => not (x == y); axiom reflex(x:t): x == x; axiom sym(x:t, y:t): (x == y) == (y == x); axiom trans(x:t, y:t, z:t): implies(x == y and y == z, x == z); } Here it is clear: the programmer must define either == or eq or both. If both are defined, the definitions must be equivalent. Failing to define one doesn't cause a compiler error, it causes an infinite loop at run time. Defining both inequivalently doesn't cause an error either, it is just inconsistent. Note the axioms specified constrain the semantics of any definition. Given a definition of == either directly or via a definition of eq, then != is defined automatically, although the programmer might replace the default with something more efficient, clearly such an overspecification has to be consistent. Please note, == could also be defined in terms of !=, but we didn't do that. A characterisation of a partial or total order is more complex. It is much more demanding since there is a combinatorial explosion of possible bases. There is an reason to desire overspecification: performance. There also another reason: choice and convenience. So here, there are several questions: one is how to check semantics are obeyed and I am not looking for an answer here (way too hard!). The other question is: How can we specify, and check, that an instance provides at least a basis? And a much harder question: how can we provide several default definitions which depend on the basis chosen?

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• Sometimes keyboard & touchpad work... sometimes not

  - by Voyagerfan5761

  When I first ran Ubuntu from CD on this Dell Inspiron 2650, it worked for about ten to fifteen minutes, then it hung (I was probably trying to do too much at once from a Live CD). The next time, my mouse and keyboard didn't work. I rebooted three times and finally got them working. I then installed Ubuntu alongside Windows XP. After installing, selecting the OS in GRUB worked, but my touchpad and keyboard were again not working. I rebooted, and they worked. (I fortunately had a USB mouse with which to reboot.) Booting Ubuntu and then rebooting to enable my keyboard and touchpad has become a routine ever since. Often several reboots are required; at one point I had to reboot over a dozen times in a row before getting a session where everything worked properly. (My installation has been in place for about three days a week now.) I've looked around for a device manager equivalent to no avail. Sometimes the hardware is properly detected, and sometimes it's not. Once or twice I've had the keyboard detected properly but the touchpad not. Plugging in my wireless card also sometimes requires a plug, unplug, and plug again to get it working. So is there some solution? I'm without an Internet connection at home, and this "laptop" is really a wall wart on my desk, so suggestions for packages may take a while to test. Xorg logs I captured two three four sample Xorg logs: one from a startup where the devices worked; one from when they didn't; one from a session where Ubuntu thought my touchpad was a normal mouse; and one from a session where my keyboard worked but the touchpad didn't. See this gist. Updated 2010-12-15 01:50 UTC with Xorg.0.log.keyboardonly file illustrating the case where the keyboard worked but not the touchpad. Updated 2011-01-11 04:10 UTC with Xorg.0.log.touchpadregmouse to illustrate a case where the touchpad was detected as a regular mouse (no "Touchpad" tab in mouse prefs).

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• Enterprise Service Bus (ESB): Important architectural piece to a SOA or is it just vendor hype?

  Is an Enterprise Service Bus (ESB) an important architectural piece to a Service-Oriented Architecture (SOA), or is it just vendor hype in order to sell a particular product such as SOA-in-a-box? According to IBM.com, an ESB is a flexible connectivity infrastructure for integrating applications and services; it offers a flexible and manageable approach to service-oriented architecture implementation. With this being said, it is my personal belief that ESBs are an important architectural piece to any SOA. Additionally, generic design patterns have been created around the integration of web services in to ESB regardless of any vendor. ESB design patterns, according to Philip Hartman, can be classified in to the following categories: Interaction Patterns: Enable service interaction points to send and/or receive messages from the bus Mediation Patterns: Enable the altering of message exchanges Deployment Patterns: Support solution deployment into a federated infrastructure Examples of Interaction Patterns: One-Way Message Synchronous Interaction Asynchronous Interaction Asynchronous Interaction with Timeout Asynchronous Interaction with a Notification Timer One Request, Multiple Responses One Request, One of Two Possible Responses One Request, a Mandatory Response, and an Optional Response Partial Processing Multiple Application Interactions Benefits of the Mediation Pattern: Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently Design an intermediary to decouple many peers Promote the many-to-many relationships between interacting peers to “full object status” Examples of Interaction Patterns: Global ESB: Services share a single namespace and all service providers are visible to every service requester across an entire network Directly Connected ESB: Global service registry that enables independent ESB installations to be visible Brokered ESB: Bridges services that are reluctant to expose requesters or providers to ESBs in other domains Federated ESB: Service consumers and providers connect to the master or to a dependent ESB to access services throughout the network References: Mediator Design Pattern. (2011). Retrieved 2011, from SourceMaking.com: http://sourcemaking.com/design_patterns/mediator Hartman, P. (2006, 24 1). ESB Patterns that "Click". Retrieved 2011, from The Art and Science of Being an IT Architect: http://artsciita.blogspot.com/2006/01/esb-patterns-that-click.html IBM. (2011). WebSphere DataPower XC10 Appliance Version 2.0. Retrieved 2011, from IBM.com: http://publib.boulder.ibm.com/infocenter/wdpxc/v2r0/index.jsp?topic=%2Fcom.ibm.websphere.help.glossary.doc%2Ftopics%2Fglossary.html Oracle. (2005). 12 Interaction Patterns. Retrieved 2011, from Oracle® BPEL Process Manager Developer's Guide: http://docs.oracle.com/cd/B31017_01/integrate.1013/b28981/interact.htm#BABHHEHD

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• Memory read/write access efficiency

  - by wolfPack88

  I've heard conflicting information from different sources, and I'm not really sure which one to believe. As such, I'll post what I understand and ask for corrections. Let's say I want to use a 2D matrix. There are three ways that I can do this (at least that I know of). 1: int i; char **matrix; matrix = malloc(50 * sizeof(char *)); for(i = 0; i < 50; i++) matrix[i] = malloc(50); 2: int i; int rowSize = 50; int pointerSize = 50 * sizeof(char *); int dataSize = 50 * 50; char **matrix; matrix = malloc(dataSize + pointerSize); char *pData = matrix + pointerSize - rowSize; for(i = 0; i < 50; i++) { pData += rowSize; matrix[i] = pData; } 3: //instead of accessing matrix[i][j] here, we would access matrix[i * 50 + j] char *matrix = malloc(50 * 50); In terms of memory usage, my understanding is that 3 is the most efficient, 2 is next, and 1 is least efficient, for the reasons below: 3: There is only one pointer and one allocation, and therefore, minimal overhead. 2: Once again, there is only one allocation, but there are now 51 pointers. This means there is 50 * sizeof(char *) more overhead. 1: There are 51 allocations and 51 pointers, causing the most overhead of all options. In terms of performance, once again my understanding is that 3 is the most efficient, 2 is next, and 1 is least efficient. Reasons being: 3: Only one memory access is needed. We will have to do a multiplication and an addition as opposed to two additions (as in the case of a pointer to a pointer), but memory access is slow enough that this doesn't matter. 2: We need two memory accesses; once to get a char *, and then to the appropriate char. Only two additions are performed here (once to get to the correct char * pointer from the original memory location, and once to get to the correct char variable from wherever the char * points to), so multiplication (which is slower than addition) is not required. However, on modern CPUs, multiplication is faster than memory access, so this point is moot. 1: Same issues as 2, but now the memory isn't contiguous. This causes cache misses and extra page table lookups, making it the least efficient of the lot. First and foremost: Is this correct? Second: Is there an option 4 that I am missing that would be even more efficient?

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• Cloud Computing: Start with the problem

  - by BuckWoody

  At one point in my life I would build my own computing system for home use. I wanted a particular video card, a certain set of drives, and a lot of memory. Not only could I not find those things in a vendor’s pre-built computer, but those were more expensive – by a lot. As time moved on and the computing industry matured, I actually find that I can buy a vendor’s system as cheaply – and in some cases far more cheaply – than I can build it myself.   This paradigm holds true for almost any product, even clothing and furniture. And it’s also held true for software… Mostly. If you need an office productivity package, you simply buy one or use open-sourced software for that. There’s really no need to write your own Word Processor – it’s kind of been done a thousand times over. Even if you need a full system for customer relationship management or other needs, you simply buy one. But there is no “cloud solution in a box”.  Sure, if you’re after “Software as a Service” – type solutions, like being able to process video (Windows Azure Media Services) or running a Pig or Hive job in Hadoop (Hadoop on Windows Azure) you can simply use one of those, or if you just want to deploy a Virtual Machine (Windows Azure Virtual Machines) you can get that, but if you’re looking for a solution to a problem your organization has, you may need to mix Software, Infrastructure, and perhaps even Platforms (such as Windows Azure Computing) to solve the issue. It’s all about starting from the problem-end first. We’ve become so accustomed to looking for a box of software that will solve the problem, that we often start with the solution and try to fit it to the problem, rather than the other way around.  When I talk with my fellow architects at other companies, one of the hardest things to get them to do is to ignore the technology for a moment and describe what the issues are. It’s interesting to monitor the conversation and watch how many times we deviate from the problem into the solution. So, in your work today, try a little experiment: watch how many times you go after a problem by starting with the solution. Tomorrow, make a conscious effort to reverse that. You might be surprised at the results.

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• How to discriminate from two nodes with identical frequencies in a Huffman's tree?

  - by Omega

  Still on my quest to compress/decompress files with a Java implementation of Huffman's coding (http://en.wikipedia.org/wiki/Huffman_coding) for a school assignment. From the Wikipedia page, I quote: Create a leaf node for each symbol and add it to the priority queue. While there is more than one node in the queue: Remove the two nodes of highest priority (lowest probability) from the queue Create a new internal node with these two nodes as children and with probability equal to the sum of the two nodes' probabilities. Add the new node to the queue. The remaining node is the root node and the tree is complete. Now, emphasis: Remove the two nodes of highest priority (lowest probability) from the queue Create a new internal node with these two nodes as children and with probability equal to the sum of the two nodes' probabilities. So I have to take two nodes with the lowest frequency. What if there are multiple nodes with the same low frequency? How do I discriminate which one to use? The reason I ask this is because Wikipedia has this image: And I wanted to see if my Huffman's tree was the same. I created a file with the following content: aaaaeeee nnttmmiihhssfffouxprl And this was the result: Doesn't look so bad. But there clearly are some differences when multiple nodes have the same frequency. My questions are the following: What is Wikipedia's image doing to discriminate the nodes with the same frequency? Is my tree wrong? (Is Wikipedia's image method the one and only answer?) I guess there is one specific and strict way to do this, because for our school assignment, files that have been compressed by my program should be able to be decompressed by other classmate's programs - so there must be a "standard" or "unique" way to do it. But I'm a bit lost with that. My code is rather straightforward. It literally just follows Wikipedia's listed steps. The way my code extracts the two nodes with the lowest frequency from the queue is to iterate all nodes and if the current node has a lower frequency than any of the two "smallest" known nodes so far, then it replaces the highest one. Just like that.

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• Blender to 3ds max to cal3d format

  - by Kaliber64

  There are quite a few questions on cal3d but they are old and don't apply anymore. In Blender(must be 2.49a for python script to work!!!): I have a scene with 7 meshes, 1 armature, 10 bones. I tried going to one mesh to simplify it but doesn't change anything. I found a small blend file that was used for cal3d and it exported just fine. So I tried to copy it's setup with no success. EDIT*8/13/2012 In the last week here is what I have found so far. I made the mesh in the newest blender(2.62?) and exported it to import it in the old one(2.49a). Did an animation in the old one because importing new blend files to old blenders, its just said it would lose keyframe data and all was good. And then you get the last problem of it not exporting meshes. BUT I found that meshes made in the old one export regardless. I can't find any that won't export. So if I used the old blender to remake my model I could get it to export :) At this point I found a modified release of cal3d (because the most core model variable would not initiate as I made a really small test subject in old blender instead of remaking my big one which took 4 hours.) which fixes the morph objects and adds what cal3d left off with. Under their license they have to release the modification but it has no documentation so I have to figure it out on my own. Its mostly the same. But with this lib it came with a 3ds max exporter. My question now is how do I transfer armature and mesh information from blender to 3ds max in order to export into cal3d format. Every time I try the models are see through and small and there are no bones. The formats I have tried to import are .3ds .obj(mesh only) and COLLADA. In all of them the mesh is invisible and no bones. It says the default texture is on so I should be able to see it. All the vertices are present I found a vertex highlighter so I can see those. If any of this is confusing let me know so I can clear it up. Its late .<=sleep.

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• Several New Hints

  - by Ondrej Brejla

  Hi all! Today we would like to introduce you some of our new experimental hints for NetBeans 7.2. They are called: Unused Use Statement and Immutable Variables. Unused Use Statement This hint is quite simple. It highlights (underlines) your use statements, which are not used. Typical use case is after some refactoring, when you forgot to remove some obsolete use statements. This hint warns you on them and allows you to remove them easily. Just click on the hint bulb in the gutter and select Remove Unused Use Statement. And of course, it works in multiple use statements combined too. Immutable Variables The next one is the hint which checks too many assignments into a variable. And why? That's simple. Mostly you should use just one assignment into one variable. But sometimes you are lazy and you do something like: But it's quite wrong, because what you really do is: And that's exactly the case, when our new hint warns you, that Too many assignments (2) into variable $foo occured. Nothing more. Yes, we know that there are some cases, where could be more assignments and no warning should occur, e.g.: Because maybe one likes longer increment syntax more than the short one. So we tried to handle these cases to don't bother you if it's not a need. Note: We are almost sure that this hint doesn't cover all your use cases, because there are a lot of them. So if you find something strange, write it into our bugzilla so we can handle it better for you. Thanks for your patience! And the last thing is, that you can set the number of allowed assignments in Tools -> Options -> Editor -> Hints -> PHP: Immutable Variables. Note: This hint works just for a common variables, not for fields. We have an enhancement request for that and it should be implemented in next version of NetBeans (probably 7.3). And that's all for today and as usual, please test it and if you find something strange, don't hesitate to file a new issue (product php, component Editor). Thanks.

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• Indefinite loops where the first time is different

  - by George T

  This isn't a serious problem or anything someone has asked me to do, just a seemingly simple thing that I came up with as a mental exercise but has stumped me and which I feel that I should know the answer to already. There may be a duplicate but I didn't manage to find one. Suppose that someone asked you to write a piece of code that asks the user to enter a number and, every time the number they entered is not zero, says "Error" and asks again. When they enter zero it stops. In other words, the code keeps asking for a number and repeats until zero is entered. In each iteration except the first one it also prints "Error". The simplest way I can think of to do that would be something like the folloing pseudocode: int number = 0; do { if(number != 0) { print("Error"); } print("Enter number"); number = getInput(); }while(number != 0); While that does what it's supposed to, I personally don't like that there's repeating code (you test number != 0 twice) -something that should generally be avoided. One way to avoid this would be something like this: int number = 0; while(true) { print("Enter number"); number = getInput(); if(number == 0) { break; } else { print("Error"); } } But what I don't like in this one is "while(true)", another thing to avoid. The only other way I can think of includes one more thing to avoid: labels and gotos: int number = 0; goto question; error: print("Error"); question: print("Enter number"); number = getInput(); if(number != 0) { goto error; } Another solution would be to have an extra variable to test whether you should say "Error" or not but this is wasted memory. Is there a way to do this without doing something that's generally thought of as a bad practice (repeating code, a theoretically endless loop or the use of goto)? I understand that something like this would never be complex enough that the first way would be a problem (you'd generally call a function to validate input) but I'm curious to know if there's a way I haven't thought of.

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• Cone of Uncertainty in classic and agile projects

  - by DigiMortal

  David Starr from Scrum.org made interesting session in TechEd Europe 2012 - Implementing Scrum Using Team Foundation Server 2012. One of interesting things for me was how Cone of Uncertainty looks like in agile projects (or how agile methodologies distort the cone we know from waterfall projects). This posting illustrates two cones – one for waterfall and one for agile world. Cone of Uncertainty Cone of Uncertainty was introduced to software development community by Steve McConnell and it visualizes how accurate are our estimates over project timeline. Here is the Cone of Uncertainty when we deal with waterfall and Big Design Up-Front (BDUF). Cone of Uncertainty. Taken from MSDN Library page Estimating. The closer we are to project end the more accurate are our estimates. When project ends we know exactly how much every task took time. As we can see then cone is wide when we usually have to give our estimates – it happens somewhere between Initial Project Concept and Requirements Complete. Don’t ask me why Initial Project Concept is the stage where some companies give their best estimates – they just do it every time and doesn’t learn a thing later. This cone is inevitable for software development and agile methodologies that try to make software world better are also able to change the cone. Cone of Uncertainty in agile projects Agile methodologies usually try to avoid BDUF, waterfalls and other things that make all our mistakes highly expensive. Of course, we are not the only ones who make mistakes – don’t also forget our dear customers. Agile methodologies take development as creational work and focus on making it better. One main trick is to focus on small and short iterations. What it means? We are estimating functionalities that are easier for us to understand and implement. Therefore our estimates are more accurate. As we move from few big iterations to many small iterations we also distort and slice Cone of Uncertainty. This is how cone looks when agile methodologies are used. Cone of Uncertainty in agile projects. We have more cones to live with but they are way smaller. I don’t have any numbers to put here because I found any but still this “chart” should give you the point: more smaller iterations cause more but way smaller cones of uncertainty. We can handle these small uncertainties because steps we take to complete small tasks are more predictable and doesn’t grow very often above our heads. One more note. Consider that both of charts given in this posting describe exactly the same phase of same project – just uncertainties are different.

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• Finding "Stuff" In OUM

  - by Dave Burke

  One of the first questions people asked when they start using the Oracle Unified Method (OUM) is “how do I find X ?” Well of course no one is really looking for “X”!! but typically an OUM user might know the Task ID, or part of the Task Name, or maybe they just want to find out if there is any content within OUM that is related to a couple of keys words they have in their mind. Here are three quick tips I give people: 1. Open up one of the OUM Views, then click “Expand All”, and then use your Browser’s search function to locate a key Word. For example, Google Chrome or Internet Explorer: <CTRL> F, then type in a key Word, i.e. Architecture This is fast and easy option to use, but it only searches the current OUM page 2. Use the PDF view of OUM Open up one of the OUM Views, and then click the PDF View button located at the top of the View. Depending on your Browser’s settings, the PDF file will either open up in a new Window, or be saved to your local machine. In either case, once the PDF file is open, you can use the built in PDF search commands to search for key words across a large portion of the OUM Method Pack. This is great option for searching the entire Full Method View of OUM, including linked HTML pages, however the search will not included linked Documents, i.e. Word, Excel. 3. Use your operating systems file index to search for key words This is my favorite option, and one I use virtually every day. I happen to use Windows Search, but you could also use Google Desktop Search, of Finder on a MAC. All you need to do (on a Windows machine) is to make sure your local OUM folder structure is included in the Windows Index. Go to Control Panel, select Indexing Options, and ensure your OUM folder is included in the Index, i.e. C:/METHOD/OM40/OUM_5.6 Once your OUM folders are indexed, just open up Windows Search (or Google Desktop Search) and type in your key worlds, i.e. Unit Testing The reason I use this option the most is because the Search will take place across the entire content of the Indexed folders, included linked files. Happy searching!

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• Is it unusual for a small company (15 developers) not to use managed source/version control?

  - by LordScree

  It's not really a technical question, but there are several other questions here about source control and best practice. The company I work for (which will remain anonymous) uses a network share to host its source code and released code. It's the responsibility of the developer or manager to manually move source code to the correct folder depending on whether it's been released and what version it is and stuff. We have various spreadsheets dotted around where we record file names and versions and what's changed, and some teams also put details of different versions at the top of each file. Each team (2-3 teams) seems to do this differently within the company. As you can imagine, it's an organised mess - organised, because the "right people" know where their stuff is, but a mess because it's all different and it relies on people remembering what to do at any one time. One good thing is that everything is backed up on a nightly basis and kept indefinitely, so if mistakes are made, snapshots can be recovered. I've been trying to push for some kind of managed source control for a while, but I can't seem to get enough support for it within the company. My main arguments are: We're currently vulnerable; at any point someone could forget to do one of the many release actions we have to do, which could mean whole versions are not stored correctly. It could take hours or even days to piece a version back together if necessary We're developing new features along with bug fixes, and often have to delay the release of one or the other because some work has not been completed yet. We also have to force customers to take versions that include new features even if they just want a bug fix, because there's only really one version we're all working on We're experiencing problems with Visual Studio because multiple developers are using the same projects at the same time (not the same files, but it's still causing problems) There are only 15 developers, but we all do stuff differently; wouldn't it be better to have a standard company-wide approach we all have to follow? My questions are: Is it normal for a group of this size not to have source control? I have so far been given only vague reasons for not having source control - what reasons would you suggest could be valid for not implementing source control, given the information above? Are there any more reasons for source control that I could add to my arsenal? I'm asking mainly to get a feel for why I have had so much resistance, so please answer honestly. I'll give the answer to the person I believe has taken the most balanced approach and has answered all three questions. Thanks in advance

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• MVC - Cocoa interface - Cocoa Design pattern book

  - by Idan

  So I started reading this book: http://www.amazon.com/Cocoa-Design-Patterns-Erik-Buck/dp/0321535022 On chapter 2 it explains about the MVC design pattern and gives and example which I need some clarification to. The simple example shows a view with the following fields: hourlyRate, WorkHours, Standarthours , salary. The example is devided into 3 parts : View - contains some text fiels and a table (the table contains a list of employees' data). Controller - comprised of NSArrayController class (contains an array of MyEmployee) Model - MyEmployee class which describes an employee. MyEmployee class has one method which return the salary according to the calculation logic, and attributes in accordance with the view UI controls. MyEmployee inherits from NSManagedObject. Few things i'm not sure of : 1. Inside the MyEmplpyee class implemenation file, the calculation method gets the class attributes using sentence like " [[self valueForKey:@"hourlyRate"] floatValue];" Howevern, inside the header there is no data member named hourlyRate or any of the view fields. I'm not quite sure how does it work, and how it gets the value from the right view field. (does it have to be the same name as the field name in the view). maybe the conncetion is made somehow using the Interface builder and was not shown in the book ? and more important: 2. how does it seperate the view from the model ? let's say ,as the book implies might happen, I decide one day to remove one of the fields in the view. as far as I understand, that means changing the way the salary method works in MyEmplpyee (cause we have one field less) , and removing one attribute from the same calss. So how is that separate the View from the Model if changing one reflect on the other ? I guess I get something wrong... Any comments ? Thanks

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