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• BI&EPM in Focus June 2014

  - by Mike.Hallett(at)Oracle-BI&EPM

  Applications Webcast Centre – A Library of Discussion and Research for Best Practice: Achieving Reliable Planning, Budgeting and Forecasting Talent Analytics and Big Data – Is HR ready for the challenge Enterprise Data – The cost of non-quality Customers Josephine Niemiec from ADP talks about Oracle Hyperion Workforce Planning at Collaborate 2014 (link) Video Chris Nelms from Ameren talks about Oracle BI Spend and Procurement Analytics at Collaborate 2014 (link) Video Leggett & Platt Leverages Oracle Hyperion EPM and Demantra (link) Video Pella Corporation Accelerates Close Cycle by Cutting Time for Financial Consolidation from Three Days to Less Than One Day (link) Secretaría General de Administración de Justicia en España Enhances Citizen Services with Near-Real-Time Business Intelligence Gleaned from 500 Databases  (link) Bellco Credit Union Speeds Budget Development by 30%—Gains Insight into Specific Branch and Financial Product Profitability  (link)  Video QDQ media Speeds up Financial Reporting by 24x, Gains Business Agility, and Integrates Seamlessly into Corporate Accounting System  (link) Westfield Group Maximizes Shopping Mall Revenue, Shortens Year-End Financial Consolidation by 75%  (link)  IL&FS Transportation Networks Shortens Financial Consolidation and Reporting Cycle by Eight Days, Gains In-Depth Insight into Business Performance   (link) Angel Trains Optimizes Rail Operations for Purchasing, Sourcing, and Project Management to Meet Challenges of Evolving Rail Industry  (link) Enterprise Performance Management June 11, at Oracle Utrecht, NL: Morning session: Explore Planning and Budgeting in the Cloud (link) June 12, London: PureApps Presents: Best Practice Financial Consolidation and Reporting Workshop (link) July 3, Koln: Oracle Hyperion Business Analytics Roundtable (link) Blog: What's Your Tax Strategy? Automate the Operational Transfer Pricing Process (link) YouTube Video: Automate Tax Reporting with Oracle Hyperion Tax Provision (link) YouTube Video: Introducing Oracle Hyperion Planning’s Tablet Optimized Interface (link) OracleEPMWebcasts @ YouTube (link) Partner webcasts: Wednesday, 4 June, 5.00 GMT - Case Study:  Lessons Learned from Edgewater Ranzal's Internal Implementation of Oracle Planning & Budgeting Cloud Service (PBCS) - Learn more and register here! Thursday, 5 June, 4.00 GMT - Achieving Accountable Care Using Oracle Technology - Learn more and register here! Tuesday, 17 June, 4.00 GMT - Optimizing Performance for Oracle EPM Systems - Learn more and register here! Oracle University Blog: The Coolest Features Available with Oracle Hyperion 11.1.2.3 – Training from OU to help you to best use them (link) Support: Proactive Support: EPM Hyperion Planning 11.1.2.3.500 Using RMI Service [Blog] Proactive Support: Planning and Budgeting Cloud Service Videos (link) Planning and Budgeting Cloud Service (PBCS) 11.1.2.3.410 Patch Bundle [Doc ID 1670981.1] Hyperion Analytic Provider Services 11.1.2.2.106 Patch Set Update [Doc ID 1667350.1] Hyperion Essbase 11.1.2.2.106 Patch Set Update [Doc ID 1667346.1] Hyperion Essbase Administration Services 11.1.2.2.106 Patch Set Update [Doc ID 1667348.1] Hyperion Essbase Studio 11.1.2.2.106 Patch Set Update [Doc ID 1667329.1] Hyperion Smart View 11.1.2.5.210 Patch Set Update [Doc ID 1669427.1] Using HPCM, HSF or DRM Communities (link) Business Intelligence June 12, Birmingham, UK: Oracle Big Data at Work - Use Cases and Architecture (link) June 17, London: Oracle at Cloud & Big Data World Forums (link) June 17, Partner Webcast: Transform your Planning Capabilities with Peloton's CloudAccelerator for Oracle PBCS (link) June 19, London: Oracle at the Whitehall Media Big Data Analytics Conference and Exhibition (link) June 19, London: Partner Event - Agile BI Conference by Peak Indicators [link] June 25, Munich: Oracle Special Day auf der TDWI 2014 Konferenz (link) July 15, London: Oracle Endeca Information Discovery Workshop (link) July 16, London: BI Applications Workshop – Financial Analytics & Procurement Analytics (link) July 17, London: BI Applications Workshop – HR Analytics (link) Milan, Italy: L’Osservatorio Big Data Analytics & Business Intelligence with Politecnico di Milano (link) OBIA 11.1.1.8.1 - Now Available [Blog] What’s New in OBIA 11.1.1.8.1 [Blog] BI Blog: A closer look at Oracle BI Applications 11.1.1.8.1 release (link) Press Release: BI Applications Deliver Greater Insight into Talent and Procurement (link) Support Blog: OBIA 11.1.1.8.1 Upgrade Guide & Documentation (link) YouTube Video: Glenn Hoormann of Ludus talks to us about Oracle Business Intelligence and ERP at Collaborate 2014 (Link) YouTube Video: Performance Architects talks about key BI and Mobile trends, including Endeca at Collaborate 2014 (link) Big Data Blog: 3 Keys for Using Big Data Effectively for Enhanced Customer Experience (link) Big Data Lite Demo VM 3.0 Now Available on OTN BI Blog: Data Relationship Governance - Workflow in a Bottle (link) MDM Blog: Register for Product Data Management Weekly Cloudcasts (link) MDM Blog: Improve your Customer Experience with High Quality Information (link) MDM Blog: Big Data Challenges & Considerations (link) Oracle University: Oracle BI Applications 11g: Implementation using ODI (link) Proactive Support: Monthly Index [Blog] My Oracle Support: Partner Accreditation for Business Analytics Support [Blog] OBIEE 11g Test-to-Production (T2P) / Clone Procedures Guide [Blog] Normal 0 false false false EN-GB 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; 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;}

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• How big can my SharePoint 2010 installation be?

  - by Sahil Malik

  Ad:: SharePoint 2007 Training in .NET 3.5 technologies (more information). 3 years ago, I had published “How big can my SharePoint 2007 installation be?” Well, SharePoint 2010 has significant under the covers improvements. So, how big can your SharePoint 2010 installation be? There are three kinds of limits you should know about Hard limits that cannot be exceeded by design. Configurable that are, well configurable – but the default values are set for a pretty good reason, so if you need to tweak, plan and understand before you tweak. Soft limits, you can exceed them, but it is not recommended that you do. Before you read any of the limits, read these two important disclaimers - 1. The limit depends on what you’re doing. So, don’t take the below as gospel, the reality depends on your situation. 2. There are many additional considerations in planning your SharePoint solution scalability and performance, besides just the below. So with those in mind, here goes.   Hard Limits - Zones per web app 5 RBS NAS performance Time to first byte of any response from NAS must be less than 20 milliseconds List row size 8000 bytes driven by how SP stores list items internally Max file size 2GB (default is 50MB, configurable). RBS does not increase this limit. Search metadata properties 10,000 per item crawled (pretty damn high, you’ll never need to worry about it). Max # of concurrent in-memory enterprise content types 5000 per web server, per tenant Max # of external system connections 500 per web server PerformancePoint services using Excel services as a datasource No single query can fetch more than 1 million excel cells Office Web Apps Renders One doc per second, per CPU core, per Application server, limited to a maximum of 8 cores.   Configurable Limits - Row Size Limit 6, configurable via SPWebApplication.MaxListItemRowStorage property List view lookup 8 join operations per query Max number of list items that a single operation can process at one time in normal hours 5000 Configurable via SPWebApplication.MaxItemsPerThrottledOperation   Also you get a warning at 3000, which is configurable via SPWebApplication.MaxItemsPerThrottledOperationWarningLevel   In addition, throttle overrides can be requested, throttle overrides can be disabled, and time windows can be set when throttle is disabled. Max number of list items for administrators that a single operation can process at one time in normal hours 20000 Configurable via SPWebApplication.MaxItemsPerThrottledOperationOverride Enumerating subsites 2000 Word and Powerpoint co-authoring simultaneous editors 10 (Hard limit is 99). # of webparts on a page 25 Search Crawl DBs per search service app 10 Items per crawl db 25 million Search Keywords 200 per site collection. There is a max limit of 5000, which can then be modified by editing the web.config/client.config. Concurrent # of workflows on a content db 15. Workflows running in the timer service are not counted in this limit. Further workflows are queued. Can be configured via the Set-SPFarmConfig powershell commandlet. Number of events picked by the workflow timer job and delivered to workflows 100. You can increase this limit by running additional instances of the workflow timer service. Visio services file size 50MB Visio web drawing recalculation timeout 120 seconds Configurable via – Powershell commandlet Set-SPVisioPerformance Visio services minimum and maximum cache age for data connected diagrams 0 to 24 hours. Default is 60 minutes. Configurable via – Powershell commandlet Set-SPVisioPerformance   Soft Limits - Content Databases 300 per web app Application Pools 10 per web server Managed Paths 20 per web app Content Database Size 200GB per Content DB Size of 1 site collection 100GB # of sites in a site collection 250,000 Documents in a library 30 Million, with nesting. Depends heavily on type and usage and size of documents. Items 30 million. Depends heavily on usage of items. SPGroups one SPUser can be in 5000 Users in a site collection 2 million, depends on UI, nesting, containers and underlying user store AD Principals in a SPGroup 5000 SPGroups in a site collection 10000 Search Service Instances 20 Indexed Items in Search 100 million Crawl Log entries 100 million Search Alerts 1 million per search application Search Crawled Properties 1/2 million URL removals in search 100 removals per operation User Profiles 2 million per service application Social Tags 500 million per social database Comment on the article ....

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• CLR via C# 3rd Edition is out

  - by Abhijeet Patel

  Time for some book news update. CLR via C#, 3rd Edition seems to have been out for a little while now. The book was released in early Feb this year, and needless to say my copy is on it’s way. I can barely wait to dig in and chew on the goodies that one of the best technical authors and software professionals I respect has in store. The 2nd edition of the book was an absolute treat and this edition promises to be no less. Here is a brief description of what’s new and updated from the 2nd edition. Part I – CLR Basics Chapter 1-The CLR’s Execution Model Added about discussion about C#’s /optimize and /debug switches and how they relate to each other. Chapter 2-Building, Packaging, Deploying, and Administering Applications and Types Improved discussion about Win32 manifest information and version resource information. Chapter 3-Shared Assemblies and Strongly Named Assemblies Added discussion of TypeForwardedToAttribute and TypeForwardedFromAttribute. Part II – Designing Types Chapter 4-Type Fundamentals No new topics. Chapter 5-Primitive, Reference, and Value Types Enhanced discussion of checked and unchecked code and added discussion of new BigInteger type. Also added discussion of C# 4.0’s dynamic primitive type. Chapter 6-Type and Member Basics No new topics. Chapter 7-Constants and Fields No new topics. Chapter 8-Methods Added discussion of extension methods and partial methods. Chapter 9-Parameters Added discussion of optional/named parameters and implicitly-typed local variables. Chapter 10-Properties Added discussion of automatically-implemented properties, properties and the Visual Studio debugger, object and collection initializers, anonymous types, the System.Tuple type and the ExpandoObject type. Chapter 11-Events Added discussion of events and thread-safety as well as showing a cool extension method to simplify the raising of an event. Chapter 12-Generics Added discussion of delegate and interface generic type argument variance. Chapter 13-Interfaces No new topics. Part III – Essential Types Chapter 14-Chars, Strings, and Working with Text No new topics. Chapter 15-Enums Added coverage of new Enum and Type methods to access enumerated type instances. Chapter 16-Arrays Added new section on initializing array elements. Chapter 17-Delegates Added discussion of using generic delegates to avoid defining new delegate types. Also added discussion of lambda expressions. Chapter 18-Attributes No new topics. Chapter 19-Nullable Value Types Added discussion on performance. Part IV – CLR Facilities Chapter 20-Exception Handling and State Management This chapter has been completely rewritten. It is now about exception handling and state management. It includes discussions of code contracts and constrained execution regions (CERs). It also includes a new section on trade-offs between writing productive code and reliable code. Chapter 21-Automatic Memory Management Added discussion of C#’s fixed state and how it works to pin objects in the heap. Rewrote the code for weak delegates so you can use them with any class that exposes an event (the class doesn’t have to support weak delegates itself). Added discussion on the new ConditionalWeakTable class, GC Collection modes, Full GC notifications, garbage collection modes and latency modes. I also include a new sample showing how your application can receive notifications whenever Generation 0 or 2 collections occur. Chapter 22-CLR Hosting and AppDomains Added discussion of side-by-side support allowing multiple CLRs to be loaded in a single process. Added section on the performance of using MarshalByRefObject-derived types. Substantially rewrote the section on cross-AppDomain communication. Added section on AppDomain Monitoring and first chance exception notifications. Updated the section on the AppDomainManager class. Chapter 23-Assembly Loading and Reflection Added section on how to deploy a single file with dependent assemblies embedded inside it. Added section comparing reflection invoke vs bind/invoke vs bind/create delegate/invoke vs C#’s dynamic type. Chapter 24-Runtime Serialization This is a whole new chapter that was not in the 2nd Edition. Part V – Threading Chapter 25-Threading Basics Whole new chapter motivating why Windows supports threads, thread overhead, CPU trends, NUMA Architectures, the relationship between CLR threads and Windows threads, the Thread class, reasons to use threads, thread scheduling and priorities, foreground thread vs background threads. Chapter 26-Performing Compute-Bound Asynchronous Operations Whole new chapter explaining the CLR’s thread pool. This chapter covers all the new .NET 4.0 constructs including cooperative cancelation, Tasks, the aralle class, parallel language integrated query, timers, how the thread pool manages its threads, cache lines and false sharing. Chapter 27-Performing I/O-Bound Asynchronous Operations Whole new chapter explaining how Windows performs synchronous and asynchronous I/O operations. Then, I go into the CLR’s Asynchronous Programming Model, my AsyncEnumerator class, the APM and exceptions, Applications and their threading models, implementing a service asynchronously, the APM and Compute-bound operations, APM considerations, I/O request priorities, converting the APM to a Task, the event-based Asynchronous Pattern, programming model soup. Chapter 28-Primitive Thread Synchronization Constructs Whole new chapter discusses class libraries and thread safety, primitive user-mode, kernel-mode constructs, and data alignment. Chapter 29-Hybrid Thread Synchronization Constructs Whole new chapter discussion various hybrid constructs such as ManualResetEventSlim, SemaphoreSlim, CountdownEvent, Barrier, ReaderWriterLock(Slim), OneManyResourceLock, Monitor, 3 ways to solve the double-check locking technique, .NET 4.0’s Lazy and LazyInitializer classes, the condition variable pattern, .NET 4.0’s concurrent collection classes, the ReaderWriterGate and SyncGate classes.

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• User Productivity Kit - Powerful Packages (Part 2)

  - by [email protected]

  In my first post on packages I described what a package is and how it can be used. I also started explaining some of the considerations that should be taken into account when determining how to arrange your packages. The first is when the files are interrelated and depend on one another such as an HTML file and it's graphics. A second consideration is how the files are used in your outlines. Let's say you're using a dozen Word doc files. You could place them all in a single package or put each Word doc file in a separate package but what's the right thing to do? There are several factors that will influence your decision. To understand the first, let me explain a function of UPK publishing. Take an outline in UPK that has an attachment (concept, frame link, or hyperlink) that points to a file in a package. When you publish this outline, the publishing engine will determine that there is a link to a file in the package and copy the contents of the package to the publishing destination directory. This is done to ensure that any interrelated files are kept together. For the situation where you have an HTML file with links to number of graphics files, this is a good thing. If, however, the package has a dozen unrelated Word doc files and you link to only one of them, all dozen Word documents will be copied to the publishing destination directory.  Whether or not this is a good thing is dependent on two things. First, are all of the files in the package used in the outline that you're publishing? Take an outline that includes links to all of the Word documents in that dozen document package I described earlier. For this situation, you may choose to keep all the files in a single package for convenience. A second consideration is how your organization leverages reuse in UPK. In this context, I'm referring to the link style of reuse such as when you link to the same topic from multiple UPK outlines and changes to the topic appear in both places. Take an example where you have the earlier mentioned dozen Word document package and an outline with a dozen topics in it. Each topic has an attachment pointing to one of the Word documents in the package (frame link, concept, etc.) If you're only publishing this outline, the single package probably works fine but what if you're reusing one of these topics in another outline? As I explained earlier, linking to one file in the package will result in all files in the package being copied to your published output. In this example, linking to one topic in the first outline will result in all dozen Word documents being copied to the published output. This may result in files in the output that you don't want there for business or size reasons. This is a situation in which you should consider placing each of the Word documents in it's own separate package. With each document in it's own package, that link to a single document will result in only that single package and single Word document being copied to the published output. In my last post I had described that packages are documents in the UPK library. When using the multi-user version of the UPK Developer you can leverage standard library capabilities for managing the files in these packages during the development process - capabilities such as check in / check out, history, etc. When structuring your packages take into consideration how the authors are going to be adding, modifying and deleting files from the packages. A single package is a single document in the UPK library. Like any other document in the library, a single user can check out the package and edit it at a time. If you have a large number of files in a single package and these must be modified by many users, you need to consider whether this will cause problems as multiple users compete to update the same package. If the files don't depend on each other consider placing the files in separate packages to reduce contention. I hope you've enjoyed these two posts on how you can leverage the power of packages in your content. In summary, consider the following when structuring your packages: Is the asset a single, standalone file or a set of files that depend on each other? Will all the files always be used together in a single outline or may only some of the files be needed based on how the content is reused across multiple outlines? Will multiple developers need to update the files in a single package or should you break it into multiple packages to reduce contention when checking out the document? We'd like to hear from you on how you're using packages in your content. Please add your comments below! Thank you and I hope these two posts have given you additional insights into how to use packages in your content and structure them for efficient use. John Zaums Senior Director, Product Development Oracle User Productivity Kit

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• Trace File Source Adapter

  The Trace File Source adapter is a useful addition to your SSIS toolbox.  It allows you to read 2005 and 2008 profiler traces stored as .trc files and read them into the Data Flow.  From there you can perform filtering and analysis using the power of SSIS. There is no need for a SQL Server connection this just uses the trace file. Example Usages Cache warming for SQL Server Analysis Services Reading the flight recorder Find out the longest running queries on a server Analyze statements for CPU, memory by user or some other criteria you choose Properties The Trace File Source adapter has two properties, both of which combine to control the source trace file that is read at runtime. SQL Server 2005 and SQL Server 2008 trace files are supported for both the Database Engine (SQL Server) and Analysis Services. The properties are managed by the Editor form or can be set directly from the Properties Grid in Visual Studio. Property Type Description AccessMode Enumeration This property determines how the Filename property is interpreted. The values available are: DirectInput Variable Filename String This property holds the path for trace file to load (*.trc). The value is either a full path, or the name of a variable which contains the full path to the trace file, depending on the AccessMode property. Trace Column Definition Hopefully the majority of you can skip this section entirely, but if you encounter some problems processing a trace file this may explain it and allow you to fix the problem. The component is built upon the trace management API provided by Microsoft. Unfortunately API methods that expose the schema of a trace file have known issues and are unreliable, put simply the data often differs from what was specified. To overcome these limitations the component uses  some simple XML files. These files enable the trace column data types and sizing attributes to be overridden. For example SQL Server Profiler or TMO generated structures define EventClass as an integer, but the real value is a string. TraceDataColumnsSQL.xml  - SQL Server Database Engine Trace Columns TraceDataColumnsAS.xml    - SQL Server Analysis Services Trace Columns The files can be found in the %ProgramFiles%\Microsoft SQL Server\100\DTS\PipelineComponents folder, e.g. "C:\Program Files\Microsoft SQL Server\100\DTS\PipelineComponents\TraceDataColumnsSQL.xml" "C:\Program Files\Microsoft SQL Server\100\DTS\PipelineComponents\TraceDataColumnsAS.xml" If at runtime the component encounters a type conversion or sizing error it is most likely due to a discrepancy between the column definition as reported by the API and the actual value encountered. Whilst most common issues have already been fixed through these files we have implemented specific exception traps to direct you to the files to enable you to fix any further issues due to different usage or data scenarios that we have not tested. An example error that you can fix through these files is shown below. Buffer exception writing value to column 'Column Name'. The string value is 999 characters in length, the column is only 111. Columns can be overridden by the TraceDataColumns XML files in "C:\Program Files\Microsoft SQL Server\100\DTS\PipelineComponents\TraceDataColumnsAS.xml". Installation The component is provided as an MSI file which you can download and run to install it. This simply places the files on disk in the correct locations and also installs the assemblies in the Global Assembly Cache as per Microsoft’s recommendations. You may need to restart the SQL Server Integration Services service, as this caches information about what components are installed, as well as restarting any open instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. Finally you will have to add the transformation to the Visual Studio toolbox manually. Right-click the toolbox, and select Choose Items.... Select the SSIS Data Flow Items tab, and then check the Trace File Source transformation in the Choose Toolbox Items window. This process has been described in detail in the related FAQ entry for How do I install a task or transform component? We recommend you follow best practice and apply the current Microsoft SQL Server Service pack to your SQL Server servers and workstations. Please note that the Microsoft Trace classes used in the component are not supported on 64-bit platforms. To use the Trace File Source on a 64-bit host you need to ensure you have the 32-bit (x86) tools available, and the way you execute your package is setup to use them, please see the help topic 64-bit Considerations for Integration Services for more details. Downloads Trace Sources for SQL Server 2005 -- Trace Sources for SQL Server 2008 Version History SQL Server 2008 Version 2.0.0.382 - SQL Sever 2008 public release. (9 Apr 2009) SQL Server 2005 Version 1.0.0.321 - SQL Server 2005 public release. (18 Nov 2008) -- Screenshots

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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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• Project of Projects with team Foundation Server 2010

  - by Martin Hinshelwood

  It is pretty much accepted that you should use Areas instead of having many small Team Projects when you are using Team Foundation Server 2010. I have implemented this scenario many times and this is the current iteration of layout and considerations. If like me you work with many customers you will find that you get into a grove for how to set these things up to make them as easily understandable for everyone, while giving the best functionality. The trick is in making it as intuitive as possible for both you and the developers that need to work with it. There are five main places where you need to have the Product or Project name in prominence of any other value. Area Iteration Source Code Work Item Queries Build Once you decide how you are doing this in each of these places you need to keep to it religiously. Evan if you have one source code file to keep, make sure it is in the right place. This makes your developers and others working with the format familiar with where everything should go, as well as building up mussel memory. This prevents the neat system degenerating into a nasty mess. Areas Areas are traditionally used to separate out parts of your product / project so that you can see how much effort has gone into each. Figure: The top level areas are for reporting and work item separation There are massive advantages of using this method. You can: move work from one project to another rename a project / product It is far more likely that a project or product gets renamed than a department. Tip: If you have many projects, over 100, you should consider categorising them here, but make sure that the actual project name always sits at the same level so you know which is which. Figure: Always keep things that are the same at the same level Note: You may use these categories only at the Area/Iteration level to make it easier to select on drop down lists. You may not want to use them everywhere. On the other hand, for consistency it would be better to. Iterations Iterations are usually used to some sort of time based consideration. Here I am splitting into Iterations with periodic releases. Figure: Each product needs to be able to have its own cadence The ability to have each project run at its own pace and to enable them to have their own release schedule is often of paramount importance and you don’t want to fix your 100+ projects to all be released on the same date. Source Code Having a good structure for your source even if you are not branching or having multiple products under the same structure is always a good idea. Figure: Separate out your products source You need to think about both your branches as well as the structure of your source. All your code should be under “Source” and everything you need to build your solution including Build Scripts and 3rd party tools should be under your “Main” (branch) folder. This should them be branched by “Quality”, “Release” or both to get the most out of your branching structure. The important thing is to make sure you branch (or be able to branch) everything you need to build, test and deploy your application to an environment. That environment may be development, test or even production, but I can’t stress the importance of having everything your need. Note: You usually will not be able to install custom software on your build server. Store any *.dll’s or *.exe’s that you need under the “Tools\Tool1” folder. Note: Consult the Branching Guidance for Team Foundation Server 2010 for more on branching Figure: Adding category may be a necessary evil Even if you have to have a couple of categories called “Default”, it is better than not knowing the difference between a folder, Product and Branch. Work Item Queries Queries are used to load lists of Work Items out of TFS so you can see what work you have. This means that you want to also separate queries out by Product / project to make it easier to Figure: Again you have the same first level structure Having Folders also in Work Item Tracking we do the same thing. We put all the queries under a folder named for the Product / Project and change each query to have “AreaPath=[TeamProject]\[ProductX]” in the query instead of the standard “Project=@Project”. Tip: Don’t have a folder with new queries for each iteration. Instead have a single “Current” folder that has queries that point to the current iteration. Just change the queries as you move from one iteration to another. Tip: You can ctrl+drag the “Product1” folder to create your “Product2” folder. Builds You may have many builds both for individual products but also for different quality's. This can be further complicated by having some builds that action “Gated Check-In” and others that are specifically for “Release”, “Test” or another purpose. Figure: There are no folders, yet, for the builds so you need a good naming convention Its a pity that there are no folders under builds, some way to categorise would be nice. In lue of that at the moment you can use a functional naming convention that at least allows you to find what you want. Conclusion It is really easy to both achieve and to stick to this format if you take the time to do it. Unless you have 1000+ builds or 100+ Products you are unlikely run into any issues. Even then there are things you can do to mitigate the issues and I have describes some of them above. Let me know if you can think of any other things to make this easier.

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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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• Take Two: Comparing JVMs on ARM/Linux

  - by user12608080

  Although the intent of the previous article, entitled Comparing JVMs on ARM/Linux, was to introduce and highlight the availability of the HotSpot server compiler (referred to as c2) for Java SE-Embedded ARM v7,  it seems, based on feedback, that everyone was more interested in the OpenJDK comparisons to Java SE-E.  In fact there were two main concerns: The fact that the previous article compared Java SE-E 7 against OpenJDK 6 might be construed as an unlevel playing field because version 7 is newer and therefore potentially more optimized. That the generic compiler settings chosen to build the OpenJDK implementations did not put those versions in a particularly favorable light. With those considerations in mind, we'll institute the following changes to this version of the benchmarking: In order to help alleviate an additional concern that there is some sort of benchmark bias, we'll use a different suite, called DaCapo.  Funded and supported by many prestigious organizations, DaCapo's aim is to benchmark real world applications.  Further information about DaCapo can be found at http://dacapobench.org. At the suggestion of Xerxes Ranby, who has been a great help through this entire exercise, a newer Linux distribution will be used to assure that the OpenJDK implementations were built with more optimal compiler settings.  The Linux distribution in this instance is Ubuntu 11.10 Oneiric Ocelot. Having experienced difficulties getting Ubuntu 11.10 to run on the original D2Plug ARMv7 platform, for these benchmarks, we'll switch to an embedded system that has a supported Ubuntu 11.10 release.  That platform is the Freescale i.MX53 Quick Start Board.  It has an ARMv7 Coretex-A8 processor running at 1GHz with 1GB RAM. We'll limit comparisons to 4 JVM implementations: Java SE-E 7 Update 2 c1 compiler (default) Java SE-E 6 Update 30 (c1 compiler is the only option) OpenJDK 6 IcedTea6 1.11pre 6b23~pre11-0ubuntu1.11.10.2 CACAO build 1.1.0pre2 OpenJDK 6 IcedTea6 1.11pre 6b23~pre11-0ubuntu1.11.10.2 JamVM build-1.6.0-devel Certain OpenJDK implementations were eliminated from this round of testing for the simple reason that their performance was not competitive.  The Java SE 7u2 c2 compiler was also removed because although quite respectable, it did not perform as well as the c1 compilers.  Recall that c2 works optimally in long-lived situations.  Many of these benchmarks completed in a relatively short period of time.  To get a feel for where c2 shines, take a look at the first chart in this blog. The first chart that follows includes performance of all benchmark runs on all platforms.  Later on we'll look more at individual tests.  In all runs, smaller means faster.  The DaCapo aficionado may notice that only 10 of the 14 DaCapo tests for this version were executed.  The reason for this is that these 10 tests represent the only ones successfully completed by all 4 JVMs.  Only the Java SE-E 6u30 could successfully run all of the tests.  Both OpenJDK instances not only failed to complete certain tests, but also experienced VM aborts too. One of the first observations that can be made between Java SE-E 6 and 7 is that, for all intents and purposes, they are on par with regards to performance.  While it is a fact that successive Java SE releases add additional optimizations, it is also true that Java SE 7 introduces additional complexity to the Java platform thus balancing out any potential performance gains at this point.  We are still early into Java SE 7.  We would expect further performance enhancements for Java SE-E 7 in future updates. In comparing Java SE-E to OpenJDK performance, among both OpenJDK VMs, Cacao results are respectable in 4 of the 10 tests.  The charts that follow show the individual results of those four tests.  Both Java SE-E versions do win every test and outperform Cacao in the range of 9% to 55%. For the remaining 6 tests, Java SE-E significantly outperforms Cacao in the range of 114% to 311% So it looks like OpenJDK results are mixed for this round of benchmarks.  In some cases, performance looks to have improved.  But in a majority of instances, OpenJDK still lags behind Java SE-Embedded considerably. Time to put on my asbestos suit.  Let the flames begin...

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• Data Source Security Part 5

  - by Steve Felts

  If you read through the first four parts of this series on data source security, you should be an expert on this focus area.  There is one more small topic to cover related to WebLogic Resource permissions.  After that comes the test, I mean example, to see with a real set of configuration parameters what the results are with some concrete values. WebLogic Resource Permissions All of the discussion so far has been about database credentials that are (eventually) used on the database side.  WLS has resource credentials to control what WLS users are allowed to access JDBC resources.  These can be defined on the Policies tab on the Security tab associated with the data source.  There are four permissions: “reserve” (get a new connection), “admin”, “shrink”, and reset (plus the all-inclusive “ALL”); we will focus on “reserve” here because we are talking about getting connections.  By default, JDBC resource permissions are completely open – anyone can do anything.  As soon as you add one policy for a permission, then all other users are restricted.  For example, if I add a policy so that “weblogic” can reserve a connection, then all other users will fail to reserve connections unless they are also explicitly added.  The validation is done for WLS user credentials only, not database user credentials.  Configuration of resources in general is described at “Create policies for resource instances” http://docs.oracle.com/cd/E24329_01/apirefs.1211/e24401/taskhelp/security/CreatePoliciesForResourceInstances.html.  This feature can be very useful to restrict what code and users can get to your database. There are the three use cases: API Use database credentials User for permission checking getConnection() True or false Current WLS user getConnection(user,password) False User/password from API getConnection(user,password) True Current WLS user If a simple getConnection() is used or database credentials are enabled, the current user that is authenticated to the WLS system is checked. If database credentials are not enabled, then the user and password on the API are used. Example The following is an actual example of the interactions between identity-based-connection-pooling-enabled, oracle-proxy-session, and use-database-credentials. On the database side, the following objects are configured.- Database users scott; jdbcqa; jdbcqa3- Permission for proxy: alter user jdbcqa3 grant connect through jdbcqa;- Permission for proxy: alter user jdbcqa grant connect through jdbcqa; The following WebLogic Data Source objects are configured.- Users weblogic, wluser- Credential mapping “weblogic” to “scott”- Credential mapping "wluser" to "jdbcqa3"- Data source descriptor configured with user “jdbcqa”- All tests are run with Set Client ID set to true (more about that below).- All tests are run with oracle-proxy-session set to false (more about that below). The test program:- Runs in servlet- Authenticates to WLS as user “weblogic” Use DB Credentials Identity based getConnection(scott,***) getConnection(weblogic,***) getConnection(jdbcqa3,***) getConnection()  true  true Identity scottClient weblogicProxy null weblogic fails - not a db user User jdbcqa3Client weblogicProxy null Default user jdbcqaClient weblogicProxy null  false  true scott fails - not a WLS user User scottClient scottProxy null jdbcqa3 fails - not a WLS user User scottClient scottProxy null  true  false Proxy for scott fails weblogic fails - not a db user User jdbcqa3Client weblogicProxy jdbcqa Default user jdbcqaClient weblogicProxy null  false  false scott fails - not a WLS user Default user jdbcqaClient scottProxy null jdbcqa3 fails - not a WLS user Default user jdbcqaClient scottProxy null If Set Client ID is set to false, all cases would have Client set to null. If this was not an Oracle thin driver, the one case with the non-null Proxy in the above table would throw an exception because proxy session is only supported, implicitly or explicitly, with the Oracle thin driver. When oracle-proxy-session is set to true, the only cases that will pass (with a proxy of "jdbcqa") are the following.1. Setting use-database-credentials to true and doing getConnection(jdbcqa3,…) or getConnection().2. Setting use-database-credentials to false and doing getConnection(wluser, …) or getConnection(). Summary There are many options to choose from for data source security.  Considerations include the number and volatility of WLS and Database users, the granularity of data access, the depth of the security identity (property on the connection or a real user), performance, coordination of various components in the software stack, and driver capabilities.  Now that you have the big picture (remember that table in part 1), you can make a more informed choice.

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• What's My Problem? What's Your Problem?

  - by Jacek Ziabicki

  Software installers are not made for building demo environments. I can say this much after 12 years (on and off) of supporting my fellow sales consultants with environments for software demonstrations. When we release software, we include installation programs and procedures that are designed for use by our clients – to build a production environment and a limited number of testing, training and development environments. Different Objectives Your priorities when building an environment for client use vs. building a demo environment are very different. In a production environment, security, stability, and performance concerns are paramount. These environments are built on a specific server and rarely, if ever, moved to a different server or different network address. There is typically just one application running on a particular server (physical or virtual). Once built, the environment will be used for months or years at a time. Because of security considerations, the installation program wants to make these environments very specific to the organization using the software and the use case, encoding a fully qualified name of the server, or even the IP address on the network, in the configuration. So you either go through the installation procedure for each environment, or learn how to clone and reconfigure the software as a separate instance to build all your non-production environments. This may not matter much if the installation is as simple as clicking on the Setup program. But for enterprise applications, you have a number of configuration settings that you need to get just right – so whether you are installing from scratch or reconfiguring an existing installation, this requires both time and expertise in the particular piece of software. If you need a setup of several applications that are integrated to talk to one another, it is a whole new level of complexity. Now you need the expertise in all of the applications involved (plus the supporting technology products), and in addition to making each application work, you also have to configure the integration endpoints. Each application needs the URLs and credentials to call the integration layer, and the integration must be able to call each application. Then you have to make sure that each app has the right data so a business process initiated in one application can continue in the next. And, you will need to check that each application has the correct version and patch level for the integration to work. When building demo environments, your #1 concern is agility. If you can get away with a small number of long-running environments, you are lucky. More likely, you may get a request for a dedicated environment for a demonstration that is two weeks away: how quickly can you make this available so we still have the time to build the client-specific data? We are running a hands-on workshop next month, and we’ll need 15 instances of application X environment so each student can have a separate server for the exercises. We cannot connect to our data center from the client site, the client’s security policy won’t allow our VPN to go through – so we need a portable environment that we can bring with us. Our consultants need to be able to work at the hotel, airport, and the airplane, so we really want an environment that can run on a laptop. The client will need two playpen environments running in the cloud, accessible from their network, for a series of workshops that start two weeks from now. We have seen all of these scenarios and more. Here you would be much better served by a generic installation that would be easy to clone. Welcome to the Wonder Machine The reason I started this blog is to share a particular design of a demo environment, a special way to install software, that can address the above requirements, even for integrated setups. This design was created by a team at Oracle Utilities Global Business Unit, and we are using this setup for most of our demo environments. In a bout of modesty we called it the Wonder Machine. Over the next few posts – think of it as a novel in parts – I will tell you about the big idea, how it was implemented and what you can do with it. After we have laid down the groundwork, I would like to share some tips and tricks for users of our Wonder Machine implementation, as well as things I am learning about building portable, cloneable environments. The Wonder Machine is by no means a closed specification, it is under active development! I am hoping this blog will be of interest to two groups of readers – the users of the Wonder Machine we have built at Oracle Utilities, who want to get the most out of their demo environments and be able to reconfigure it to their needs – and to people who need to build environments for demonstration, testing, training, development and would like to make them cloneable and portable to maximize the reuse of their effort. Surely we are not the only ones facing this problem? If you can think of a better way to solve it, or if you can help us improve on our concept, I will appreciate your comments!

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• High Availability for IaaS, PaaS and SaaS in the Cloud

  - by BuckWoody

  Outages, natural disasters and unforeseen events have proved that even in a distributed architecture, you need to plan for High Availability (HA). In this entry I'll explain a few considerations for HA within Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). In a separate post I'll talk more about Disaster Recovery (DR), since each paradigm has a different way to handle that. Planning for HA in IaaS IaaS involves Virtual Machines - so in effect, an HA strategy here takes on many of the same characteristics as it would on-premises. The primary difference is that the vendor controls the hardware, so you need to verify what they do for things like local redundancy and so on from the hardware perspective. As far as what you can control and plan for, the primary factors fall into three areas: multiple instances, geographical dispersion and task-switching. In almost every cloud vendor I've studied, to ensure your application will be protected by any level of HA, you need to have at least two of the Instances (VM's) running. This makes sense, but you might assume that the vendor just takes care of that for you - they don't. If a single VM goes down (for whatever reason) then the access to it is lost. Depending on multiple factors, you might be able to recover the data, but you should assume that you can't. You should keep a sync to another location (perhaps the vendor's storage system in another geographic datacenter or to a local location) to ensure you can continue to serve your clients. You'll also need to host the same VM's in another geographical location. Everything from a vendor outage to a network path problem could prevent your users from reaching the system, so you need to have multiple locations to handle this. This means that you'll have to figure out how to manage state between the geo's. If the system goes down in the middle of a transaction, you need to figure out what part of the process the system was in, and then re-create or transfer that state to the second set of systems. If you didn't write the software yourself, this is non-trivial. You'll also need a manual or automatic process to detect the failure and re-route the traffic to your secondary location. You could flip a DNS entry (if your application can tolerate that) or invoke another process to alias the first system to the second, such as load-balancing and so on. There are many options, but all of them involve coding the state into the application layer. If you've simply moved a state-ful application to VM's, you may not be able to easily implement an HA solution. Planning for HA in PaaS Implementing HA in PaaS is a bit simpler, since it's built on the concept of stateless applications deployment. Once again, you need at least two copies of each element in the solution (web roles, worker roles, etc.) to remain available in a single datacenter. Also, you need to deploy the application again in a separate geo, but the advantage here is that you could work out a "shared storage" model such that state is auto-balanced across the world. In fact, you don't have to maintain a "DR" site, the alternate location can be live and serving clients, and only take on extra load if the other site is not available. In Windows Azure, you can use the Traffic Manager service top route the requests as a type of auto balancer. Even with these benefits, I recommend a second backup of storage in another geographic location. Storage is inexpensive; and that second copy can be used for not only HA but DR. Planning for HA in SaaS In Software-as-a-Service (such as Office 365, or Hadoop in Windows Azure) You have far less control over the HA solution, although you still maintain the responsibility to ensure you have it. Since each SaaS is different, check with the vendor on the solution for HA - and make sure you understand what they do and what you are responsible for. They may have no HA for that solution, or pin it to a particular geo, or perhaps they have a massive HA built in with automatic load balancing (which is often the case).   All of these options (with the exception of SaaS) involve higher costs for the design. Do not sacrifice reliability for cost - that will always cost you more in the end. Build in the redundancy and HA at the very outset of the project - if you try to tack it on later in the process the business will push back and potentially not implement HA. References: http://www.bing.com/search?q=windows+azure+High+Availability  (each type of implementation is different, so I'm routing you to a search on the topic - look for the "Patterns and Practices" results for the area in Azure you're interested in)

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• Cloud to On-Premise Connectivity Patterns

  - by Rajesh Raheja

  Do you have a requirement to convert an Opportunity in Salesforce.com to an Order/Quote in Oracle E-Business Suite? Or maybe you want the creation of an Oracle RightNow Incident to trigger an on-premise Oracle E-Business Suite Service Request creation for RMA and Field Scheduling? If so, read on. In a previous blog post, I discussed integrating TO cloud applications, however the use cases above are the reverse i.e. receiving data FROM cloud applications (SaaS) TO on-premise applications/databases that sit behind a firewall. Oracle SOA Suite is assumed to be on-premise with with Oracle Service Bus as the mediation and virtualization layer. The main considerations for the patterns are are security i.e. shielding enterprise resources; and scalability i.e. minimizing firewall latency. Let me use an analogy to help visualize the patterns: the on-premise system is your home - with your most valuable possessions - and the SaaS app is your favorite on-line store which regularly ships (inbound calls) various types of parcels/items (message types/service operations). You need the items at home (on-premise) but want to safe guard against misguided elements of society (internet threats) who may masquerade as postal workers and vandalize property (denial of service?). Let's look at the patterns. Pattern: Pull from Cloud The on-premise system polls from the SaaS apps and picks up the message instead of having it delivered. This may be done using Oracle RightNow Object Query Language or SOAP APIs. This is particularly suited for certain integration approaches wherein messages are trickling in, can be centralized and batched e.g. retrieving event notifications on an hourly schedule from the Oracle Messaging Service. To compare this pattern with the home analogy, you are avoiding any deliveries to your home and instead go to the post office/UPS/Fedex store to pick up your parcel. Every time. Pros: On-premise assets not exposed to the Internet, firewall issues avoided by only initiating outbound connections Cons: Polling mechanisms may affect performance, may not satisfy near real-time requirements Pattern: Open Firewall Ports The on-premise system exposes the web services that needs to be invoked by the cloud application. This requires opening up firewall ports, routing calls to the appropriate internal services behind the firewall. Fusion Applications uses this pattern, and auto-provisions the services on the various virtual hosts to secure the topology. This works well for service integration, but may not suffice for large volume data integration. Using the home analogy, you have now decided to receive parcels instead of going to the post office every time. A door mail slot cut out allows the postman can drop small parcels, but there is still concern about cutting new holes for larger packages. Pros: optimal pattern for near real-time needs, simpler administration once the service is provisioned Cons: Needs firewall ports to be opened up for new services, may not suffice for batch integration requiring direct database access Pattern: Virtual Private Networking The on-premise network is "extended" to the cloud (or an intermediary on-demand / managed service offering) using Virtual Private Networking (VPN) so that messages are delivered to the on-premise system in a trusted channel. Using the home analogy, you entrust a set of keys with a neighbor or property manager who receives the packages, and then drops it inside your home. Pros: Individual firewall ports don't need to be opened, more suited for high scalability needs, can support large volume data integration, easier management of one connection vs a multitude of open ports Cons: VPN setup, specific hardware support, requires cloud provider to support virtual private computing Pattern: Reverse Proxy / API Gateway The on-premise system uses a reverse proxy "API gateway" software on the DMZ to receive messages. The reverse proxy can be implemented using various mechanisms e.g. Oracle API Gateway provides firewall and proxy services along with comprehensive security, auditing, throttling benefits. If a firewall already exists, then Oracle Service Bus or Oracle HTTP Server virtual hosts can provide reverse proxy implementations on the DMZ. Custom built implementations are also possible if specific functionality (such as message store-n-forward) is needed. In the home analogy, this pattern sits in between cutting mail slots and handing over keys. Instead, you install (and maintain) a mailbox in your home premises outside your door. The post office delivers the parcels in your mailbox, from where you can securely retrieve it. Pros: Very secure, very flexible Cons: Introduces a new software component, needs DMZ deployment and management Pattern: On-Premise Agent (Tunneling) A light weight "agent" software sits behind the firewall and initiates the communication with the cloud, thereby avoiding firewall issues. It then maintains a bi-directional connection either with pull or push based approaches using (or abusing, depending on your viewpoint) the HTTP protocol. Programming protocols such as Comet, WebSockets, HTTP CONNECT, HTTP SSH Tunneling etc. are possible implementation options. In the home analogy, a resident receives the parcel from the postal worker by opening the door, however you still take precautions with chain locks and package inspections. Pros: Light weight software, IT doesn't need to setup anything Cons: May bypass critical firewall checks e.g. virus scans, separate software download, proliferation of non-IT managed software Conclusion The patterns above are some of the most commonly encountered ones for cloud to on-premise integration. Selecting the right pattern for your project involves looking at your scalability needs, security restrictions, sync vs asynchronous implementation, near real-time vs batch expectations, cloud provider capabilities, budget, and more. In some cases, the basic "Pull from Cloud" may be acceptable, whereas in others, an extensive VPN topology may be well justified. For more details on the Oracle cloud integration strategy, download this white paper.

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• Cloud to On-Premise Connectivity Patterns

  - by Rajesh Raheja

  Do you have a requirement to convert an Opportunity in Salesforce.com to an Order/Quote in Oracle E-Business Suite? Or maybe you want the creation of an Oracle RightNow Incident to trigger an on-premise Oracle E-Business Suite Service Request creation for RMA and Field Scheduling? If so, read on. In a previous blog post, I discussed integrating TO cloud applications, however the use cases above are the reverse i.e. receiving data FROM cloud applications (SaaS) TO on-premise applications/databases that sit behind a firewall. Oracle SOA Suite is assumed to be on-premise with with Oracle Service Bus as the mediation and virtualization layer. The main considerations for the patterns are are security i.e. shielding enterprise resources; and scalability i.e. minimizing firewall latency. Let me use an analogy to help visualize the patterns: the on-premise system is your home - with your most valuable possessions - and the SaaS app is your favorite on-line store which regularly ships (inbound calls) various types of parcels/items (message types/service operations). You need the items at home (on-premise) but want to safe guard against misguided elements of society (internet threats) who may masquerade as postal workers and vandalize property (denial of service?). Let's look at the patterns. Pattern: Pull from Cloud The on-premise system polls from the SaaS apps and picks up the message instead of having it delivered. This may be done using Oracle RightNow Object Query Language or SOAP APIs. This is particularly suited for certain integration approaches wherein messages are trickling in, can be centralized and batched e.g. retrieving event notifications on an hourly schedule from the Oracle Messaging Service. To compare this pattern with the home analogy, you are avoiding any deliveries to your home and instead go to the post office/UPS/Fedex store to pick up your parcel. Every time. Pros: On-premise assets not exposed to the Internet, firewall issues avoided by only initiating outbound connections Cons: Polling mechanisms may affect performance, may not satisfy near real-time requirements Pattern: Open Firewall Ports The on-premise system exposes the web services that needs to be invoked by the cloud application. This requires opening up firewall ports, routing calls to the appropriate internal services behind the firewall. Fusion Applications uses this pattern, and auto-provisions the services on the various virtual hosts to secure the topology. This works well for service integration, but may not suffice for large volume data integration. Using the home analogy, you have now decided to receive parcels instead of going to the post office every time. A door mail slot cut out allows the postman can drop small parcels, but there is still concern about cutting new holes for larger packages. Pros: optimal pattern for near real-time needs, simpler administration once the service is provisioned Cons: Needs firewall ports to be opened up for new services, may not suffice for batch integration requiring direct database access Pattern: Virtual Private Networking The on-premise network is "extended" to the cloud (or an intermediary on-demand / managed service offering) using Virtual Private Networking (VPN) so that messages are delivered to the on-premise system in a trusted channel. Using the home analogy, you entrust a set of keys with a neighbor or property manager who receives the packages, and then drops it inside your home. Pros: Individual firewall ports don't need to be opened, more suited for high scalability needs, can support large volume data integration, easier management of one connection vs a multitude of open ports Cons: VPN setup, specific hardware support, requires cloud provider to support virtual private computing Pattern: Reverse Proxy / API Gateway The on-premise system uses a reverse proxy "API gateway" software on the DMZ to receive messages. The reverse proxy can be implemented using various mechanisms e.g. Oracle API Gateway provides firewall and proxy services along with comprehensive security, auditing, throttling benefits. If a firewall already exists, then Oracle Service Bus or Oracle HTTP Server virtual hosts can provide reverse proxy implementations on the DMZ. Custom built implementations are also possible if specific functionality (such as message store-n-forward) is needed. In the home analogy, this pattern sits in between cutting mail slots and handing over keys. Instead, you install (and maintain) a mailbox in your home premises outside your door. The post office delivers the parcels in your mailbox, from where you can securely retrieve it. Pros: Very secure, very flexible Cons: Introduces a new software component, needs DMZ deployment and management Pattern: On-Premise Agent (Tunneling) A light weight "agent" software sits behind the firewall and initiates the communication with the cloud, thereby avoiding firewall issues. It then maintains a bi-directional connection either with pull or push based approaches using (or abusing, depending on your viewpoint) the HTTP protocol. Programming protocols such as Comet, WebSockets, HTTP CONNECT, HTTP SSH Tunneling etc. are possible implementation options. In the home analogy, a resident receives the parcel from the postal worker by opening the door, however you still take precautions with chain locks and package inspections. Pros: Light weight software, IT doesn't need to setup anything Cons: May bypass critical firewall checks e.g. virus scans, separate software download, proliferation of non-IT managed software Conclusion The patterns above are some of the most commonly encountered ones for cloud to on-premise integration. Selecting the right pattern for your project involves looking at your scalability needs, security restrictions, sync vs asynchronous implementation, near real-time vs batch expectations, cloud provider capabilities, budget, and more. In some cases, the basic "Pull from Cloud" may be acceptable, whereas in others, an extensive VPN topology may be well justified. For more details on the Oracle cloud integration strategy, download this white paper.

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• Documentation Changes in Solaris 11.1

  - by alanc

  One of the first places you can see Solaris 11.1 changes are in the docs, which have now been posted in the Solaris 11.1 Library on docs.oracle.com. I spent a good deal of time reviewing documentation for this release, and thought some would be interesting to blog about, but didn't review all the changes (not by a long shot), and am not going to cover all the changes here, so there's plenty left for you to discover on your own. Just comparing the Solaris 11.1 Library list of docs against the Solaris 11 list will show a lot of reorganization and refactoring of the doc set, especially in the system administration guides. Hopefully the new break down will make it easier to get straight to the sections you need when a task is at hand. Packaging System Unfortunately, the excellent in-depth guide for how to build packages for the new Image Packaging System (IPS) in Solaris 11 wasn't done in time to make the initial Solaris 11 doc set. An interim version was published shortly after release, in PDF form on the OTN IPS page. For Solaris 11.1 it was included in the doc set, as Packaging and Delivering Software With the Image Packaging System in Oracle Solaris 11.1, so should be easier to find, and easier to share links to specific pages the HTML version. Beyond just how to build a package, it includes details on how Solaris is packaged, and how package updates work, which may be useful to all system administrators who deal with Solaris 11 upgrades & installations. The Adding and Updating Oracle Solaris 11.1 Software Packages was also extended, including new sections on Relaxing Version Constraints Specified by Incorporations and Locking Packages to a Specified Version that may be of interest to those who want to keep the Solaris 11 versions of certain packages when they upgrade, such as the couple of packages that had functionality removed by an (unusual for an update release) End of Feature process in the 11.1 release. Also added in this release is a document containing the lists of all the packages in each of the major package groups in Solaris 11.1 (solaris-desktop, solaris-large-server, and solaris-small-server). While you can simply get the contents of those groups from the package repository, either via the web interface or the pkg command line, the documentation puts them in handy tables for easier side-by-side comparison, or viewing the lists before you've installed the system to pick which one you want to initially install. X Window System We've not had good X11 coverage in the online Solaris docs in a while, mostly relying on the man pages, and upstream X.Org docs. In this release, we've integrated some X coverage into the Solaris 11.1 Desktop Adminstrator's Guide, including sections on installing fonts for fontconfig or legacy X11 clients, X server configuration, and setting up remote access via X11 or VNC. Of course we continue to work on improving the docs, including a lot of contributions to the upstream docs all OS'es share (more about that another time). Security One of the things Oracle likes to do for its products is to publish security guides for administrators & developers to know how to build systems that meet their security needs. For Solaris, we started this with Solaris 11, providing a guide for sysadmins to find where the security relevant configuration options were documented. The Solaris 11.1 Security Guidelines extend this to cover new security features, such as Address Space Layout Randomization (ASLR) and Read-Only Zones, as well as adding additional guidelines for existing features, such as how to limit the size of tmpfs filesystems, to avoid users driving the system into swap thrashing situations. For developers, the corresponding document is the Developer's Guide to Oracle Solaris 11 Security, which has been the source for years for documentation of security-relevant Solaris API's such as PAM, GSS-API, and the Solaris Cryptographic Framework. For Solaris 11.1, a new appendix was added to start providing Secure Coding Guidelines for Developers, leveraging the CERT Secure Coding Standards and OWASP guidelines to provide the base recommendations for common programming languages and their standard API's. Solaris specific secure programming guidance was added via links to other documentation in the product doc set. In parallel, we updated the Solaris C Libary Functions security considerations list with details of Solaris 11 enhancements such as FD_CLOEXEC flags, additional *at() functions, and new stdio functions such as asprintf() and getline(). A number of code examples throughout the Solaris 11.1 doc set were updated to follow these recommendations, changing unbounded strcpy() calls to strlcpy(), sprintf() to snprintf(), etc. so that developers following our examples start out with safer code. The Writing Device Drivers guide even had the appendix updated to list which of these utility functions, like snprintf() and strlcpy(), are now available via the Kernel DDI. Little Things Of course all the big new features got documented, and some major efforts were put into refactoring and renovation, but there were also a lot of smaller things that got fixed as well in the nearly a year between the Solaris 11 and 11.1 doc releases - again too many to list here, but a random sampling of the ones I know about & found interesting or useful: The Privileges section of the DTrace Guide now gives users a pointer to find out how to set up DTrace privileges for non-global zones and what limitations are in place there. A new section on Recommended iSCSI Configuration Practices was added to the iSCSI configuration section when it moved into the SAN Configuration and Multipathing administration guide. The Managing System Power Services section contains an expanded explanation of the various tunables for power management in Solaris 11.1. The sample dcmd sources in /usr/demo/mdb were updated to include ::help output, so that developers like myself who follow the examples don't forget to include it (until a helpful code reviewer pointed it out while reviewing the mdb module changes for Xorg 1.12). The README file in that directory was updated to show the correct paths for installing both kernel & userspace modules, including the 64-bit variants.

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• Determining the angle to fire a shot when target and shooter moves, and bullet moves with shooter velocity added in

  - by Azaral

  I saw this question: Predicting enemy position in order to have an object lead its target and followed the link in the answer to stack overflow. In the stack overflow page I used the 2nd answer, the one that is a large mathematical derivation. My situation is a little different though. My first question though is will the answer provided in the stack overflow page even work to begin with, assuming the original circumstances of moving target and stationary shooter. My situation is a little different than that situation. My target moves, the shooter moves, and the bullets from the shooter start off with the velocities in x and y added to the bullets' x and y velocities. If you are sliding to the right, the bullets will remain in front of you as you move so as long as your velocity remains constant. What I'm trying to do is to get the enemy to be able to determine where they need to shoot in order to hit the player. Unless the player and enemy is stationary, the velocity from the ship adding to the velocity of the bullets will cause a miss. I'd rather like to prevent that. I used the formula in the stack overflow answer and did what I thought were the appropriate adjustments. I've been banging at this for the last four hours and I just can't make it click. It is probably something really simple and boneheaded that I am missing (that seems to be a lot of my problems lately). Here is the solution presented from the stack overflow answer: It boils down to solving a quadratic equation of the form: a * sqr(x) + b * x + c == 0 Note that by sqr I mean square, as opposed to square root. Use the following values: a := sqr(target.velocityX) + sqr(target.velocityY) - sqr(projectile_speed) b := 2 * (target.velocityX * (target.startX - cannon.X) + target.velocityY * (target.startY - cannon.Y)) c := sqr(target.startX - cannon.X) + sqr(target.startY - cannon.Y) Now we can look at the discriminant to determine if we have a possible solution. disc := sqr(b) - 4 * a * c If the discriminant is less than 0, forget about hitting your target -- your projectile can never get there in time. Otherwise, look at two candidate solutions: t1 := (-b + sqrt(disc)) / (2 * a) t2 := (-b - sqrt(disc)) / (2 * a) Note that if disc == 0 then t1 and t2 are equal. If there are no other considerations such as intervening obstacles, simply choose the smaller positive value. (Negative t values would require firing backward in time to use!) Substitute the chosen t value back into the target's position equations to get the coordinates of the leading point you should be aiming at: aim.X := t * target.velocityX + target.startX aim.Y := t * target.velocityY + target.startY Here is my code, after being corrected by Sam Hocevar (thank you again for your help!). It still doesn't work. For some reason it never enters the section of code inside the if(disc = 0) (obviously because it is always less than zero but...). However, if I plug the numbers from my game log on the enemy and player positions and velocities it outputs a valid firing solution. I have looked at the code side by side a couple of times now and I can't find any differences. There has got to be something simple I'm missing here. If someone else could look at this code and determine what is going on here I'd appreciate it. I know it's not going through that section because if it were, shouldShoot would become true and the enemy would be blasting away at the player. This section calls the function in question, CalculateShootHeading() if(shouldMove) { UseEngines(); } x += xVelocity; y += yVelocity; CalculateShootHeading(); if(shouldShoot) { ShootWeapons(); } UpdateWeapons(); This is CalculateShootHeading(). This is inside the enemy class so x and y are the enemy's x and y and the same with velocity. One output from my game log gives Player X = 2108, Player Y = -180.956, Player X velocity = 10.9949, Player Y Velocity = -6.26017, Enemy X = 1988.31, Enemy Y = -339.051, Enemy X velocity = 1.81666, Enemy Y velocity = -9.67762, 0 enemy projectiles. The output from the console tester is Bullet position = 2210.49, -239.313 and Player Position = 2210.49, -239.313. This doesn't make any sense. The only thing that could be different is the code or the input into my function in the game and I've checked that and I don't think that it is wrong as it's updated before this and never changed. float const bulletSpeed = 30.f; float const dx = playerX - x; float const dy = playerY - y; float const vx = playerXVelocity - xVelocity; float const vy = playerYVelocity - yVelocity; float const a = vx * vx + vy * vy - bulletSpeed * bulletSpeed; float const b = 2.f * (vx * dx + vy * dy); float const c = dx * dx + dy * dy; float const disc = b * b - 4.f * a * c; shouldShoot = false; if (disc >= 0.f) { float t0 = (-b - std::sqrt(disc)) / (2.f * a); float t1 = (-b + std::sqrt(disc)) / (2.f * a); if (t0 < 0.f || (t1 < t0 && t1 >= 0.f)) { t0 = t1; } if (t0 >= 0.f) { float shootx = vx + dx / t0; float shooty = vy + dy / t0; heading = std::atan2(shooty, shootx) * RAD2DEGREE; } shouldShoot = true; }

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• How to optimize Core Data query for full text search

  - by dk

  Can I optimize a Core Data query when searching for matching words in a text? (This question also pertains to the wisdom of custom SQL versus Core Data on an iPhone.) I'm working on a new (iPhone) app that is a handheld reference tool for a scientific database. The main interface is a standard searchable table view and I want as-you-type response as the user types new words. Words matches must be prefixes of words in the text. The text is composed of 100,000s of words. In my prototype I coded SQL directly. I created a separate "words" table containing every word in the text fields of the main entity. I indexed words and performed searches along the lines of SELECT id, * FROM textTable JOIN (SELECT DISTINCT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) ON id=textTableId LIMIT 50 This runs very fast. Using an IN would probably work just as well, i.e. SELECT * FROM textTable WHERE id IN (SELECT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) LIMIT 50 The LIMIT is crucial and allows me to display results quickly. I notify the user that there are too many to display if the limit is reached. This is kludgy. I've spent the last several days pondering the advantages of moving to Core Data, but I worry about the lack of control in the schema, indexing, and querying for an important query. Theoretically an NSPredicate of textField MATCHES '.*\bfoo.*' would just work, but I'm sure it will be slow. This sort of text search seems so common that I wonder what is the usual attack? Would you create a words entity as I did above and use a predicate of "word BEGINSWITH 'foo'"? Will that work as fast as my prototype? Will Core Data automatically create the right indexes? I can't find any explicit means of advising the persistent store about indexes. I see some nice advantages of Core Data in my iPhone app. The faulting and other memory considerations allow for efficient database retrievals for tableview queries without setting arbitrary limits. The object graph management allows me to easily traverse entities without writing lots of SQL. Migration features will be nice in the future. On the other hand, in a limited resource environment (iPhone) I worry that an automatically generated database will be bloated with metadata, unnecessary inverse relationships, inefficient attribute datatypes, etc. Should I dive in or proceed with caution?

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• XML: When to use attributes instead of child nodes?

  - by Rosarch

  For tree leaves in XML, when is it better to use attributes, and when is it better to use descendant nodes? For example, in the following XML document: <?xml version="1.0" encoding="utf-8" ?> <savedGame> <links> <link rootTagName="zombies" packageName="zombie" /> <link rootTagName="ghosts" packageName="ghost" /> <link rootTagName="players" packageName="player" /> <link rootTagName="trees" packageName="tree" /> </links> <locations> <zombies> <zombie> <positionX>41</positionX> <positionY>100</positionY> </zombie> <zombie> <positionX>55</positionX> <positionY>56</positionY> </zombie> </zombies> <ghosts> <ghost> <positionX>11</positionX> <positionY>90</positionY> </ghost> </ghosts> </locations> </savedGame> The <link> tag has attributes, but it could also be written as: <link> <rootTagName>trees</rootTagName> <packageName>tree</packageName> </link> Similarly, the location tags could be written as: <zombie positionX="55" positionY="56" /> instead of: <zombie> <positionX>55</positionX> <positionY>56</positionY> </zombie> What reasons are there to prefer one over the other? Is it just a stylistic issue? Any performance considerations?

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• Double Buffering for Game objects, what's a nice clean generic C++ way?

  - by Gary

  This is in C++. So, I'm starting from scratch writing a game engine for fun and learning from the ground up. One of the ideas I want to implement is to have game object state (a struct) be double-buffered. For instance, I can have subsystems updating the new game object data while a render thread is rendering from the old data by guaranteeing there is a consistent state stored within the game object (the data from last time). After rendering of old and updating of new is finished, I can swap buffers and do it again. Question is, what's a good forward-looking and generic OOP way to expose this to my classes while trying to hide implementation details as much as possible? Would like to know your thoughts and considerations. I was thinking operator overloading could be used, but how do I overload assign for a templated class's member within my buffer class? for instance, I think this is an example of what I want: doublebuffer<Vector3> data; data.x=5; //would write to the member x within the new buffer int a=data.x; //would read from the old buffer's x member data.x+=1; //I guess this shouldn't be allowed If this is possible, I could choose to enable or disable double-buffering structs without changing much code. This is what I was considering: template <class T> class doublebuffer{ T T1; T T2; T * current=T1; T * old=T2; public: doublebuffer(); ~doublebuffer(); void swap(); operator=()?... }; and a game object would be like this: struct MyObjectData{ int x; float afloat; } class MyObject: public Node { doublebuffer<MyObjectData> data; functions... } What I have right now is functions that return pointers to the old and new buffer, and I guess any classes that use them have to be aware of this. Is there a better way?

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• Repeating fields in similar database tables

  - by user1738833

  I have been tasked with working on a database that I have never seen before and I'm looking at the DB structure. Some of the central and most heavily queried and joined tables look like virtual duplicates of each other. Here's a massively simplified representation of the situation, with business-sensitive information changed, listing hypothetical table names and fields: TopLevelGroup: PK_TLGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK SubGroup: PK_SubGroupId, FK_ParentTopLevelGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK SubSubGroup: PK_SubSUbGroupId, FK_ParentSubGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK I haven't listed the types of the fields as I don't think it's particularly important to the situation. In addition, it's worth saying that rather than four repeated fields as in the example above, I'm looking at 86 repeated fields. For the most part, those fields genuinely do represent "facts" about the primary table entity, so it's not automatically wrong for that reason. In addition, the "groups" represented here have a property inheritance relationship. If DisplaysXOnBill is NULL in the SubSubGroup, it takes the value of DisplaysXOnBillfrom it's parent, the SubGroup, and so-on up to the TopLevelGroup. Further, the requirements will never require that the model extends beyond three levels, so there is no need for flexibility in that area. Is there a design smell from several tables which describe very similar entities having almost identical fields? If so, what might be a better design of the example above? I'm using the phrase "design smell" to indicate a possible problem. Of course, in any given situation, a particular design might well be the best solution. I'm looking for a more general answer - wondering what might be wrong with this design and what might be the better design were that the case. Possibly related, but not primary questions: Is this database schema in a reasonably normal form (e.g. to 3NF), insofar as can be told from the information I've provided. I can't see a problem with the requirements of 2NF and 3NF, except in their inheriting the requirements of 1NF. Is 1NF satisfied though? Are repeating groups allowed in different tables? Is there a best-practice method for implementing the inheritance relationship in a database as I require? The method above feels clunky to me because any query on the SubSubGroup necessarily needs to join onto the SubGroup and the TopLevelGroup tables to collect inherited facts, which can make even trivial joins requiring facts from the SubSubGroup table rather long-winded. There are, of course, political considerations to making a relatively large change like this. For the purpose of this question, I'm happy to ignore that fact in the interests of keeping the answers ring-fenced to the technical problem.

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• How to generate and encode (for use in GA), random, strict, binary rooted trees with N leaves?

  - by Peter Simon

  First, I am an engineer, not a computer scientist, so I apologize in advance for any misuse of nomenclature and general ignorance of CS background. Here is the motivational background for my question: I am contemplating writing a genetic algorithm optimizer to aid in designing a power divider network (also called a beam forming network, or BFN for short). The BFN is intended to distribute power to each of N radiating elements in an array of antennas. The fraction of the total input power to be delivered to each radiating element has been specified. Topologically speaking, a BFN is a strictly binary, rooted tree. Each of the (N-1) interior nodes of the tree represents the input port of an unequal, binary power splitter. The N leaves of the tree are the power divider outputs. Given a particular power divider topology, one is still free to map the power divider outputs to the array inputs in an arbitrary order. There are N! such permutations of the outputs. There are several considerations in choosing the desired ordering: 1) The power ratio for each binary coupler should be within a specified range of values. 2) The ordering should be chosen to simplify the mechanical routing of the transmission lines connecting the power divider. The number of ouputs N of the BFN may range from, say, 6 to 22. I have already written a genetic algorithm optimizer that, given a particular BFN topology and desired array input power distribution, will search through the N! permutations of the BFN outputs to generate a design with compliant power ratios and good mechanical routing. I would now like to generalize my program to automatically generate and search through the space of possible BFN topologies. As I understand it, for N outputs (leaves of the binary tree), there are $C_{N-1}$ different topologies that can be constructed, where $C_N$ is the Catalan number. I would like to know how to encode an arbitrary tree having N leaves in a way that is consistent with a chromosomal description for use in a genetic algorithm. Also associated with this is the need to generate random instances for filling the initial population, and to implement crossover and mutations operators for this type of chromosome. Any suggestions will be welcome. Please minimize the amount of CS lingo in your reply, since I am not likely to be acquainted with it. Thanks in advance, Peter

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• IPv6: Should I have private addresses?

  - by AlReece45

  Right now, we have a rack of servers. Every server right now has at least 2 IP addresses, one for the public interface, another for the private. The servers that have SSL websites on them have more IP addresses. We also have virtual servers, that are configured similarly. Private Network The private range is currently just used for backups and monitoring. Its a gigabit port, the interface usage does not usually get very high. There are other technologies we're considering using that would use this port: iSCSI (implementations usually recommends dedicating an interface to it, which would be yet another IP network), VPN to get access to the private range (something I'd rather avoid) dedicated database servers LDAP centralized configuration (like puppet) centralized logging We don't have any private addresses in our DNS records (only public addresses). For our servers to utilize the correct IP address for the right interface (and not hard code the IP address) probably requires setting up a private DNS server (So now we add 2 different dns entries to 2 different systems). Public Network Our public range has a variety of services include web, email, and ftp. There is a hardware firewall between our network and the "public" network. We have (relatively secure) method to instruct the firewall to open and close administrative access (web interfaces, ssh, etc) for our current IP address. With either solution discussed, the host-based firewalls will be configured as well. The public network currently runs at a dedicated 20Mbps link. There are a couple of legacy servers with fast-ethernet ports, but they are scheduled for decommissioning. All of the other production boxes have at least 2 Gigabit Ethernet ports. The more traffic-heavy servers have 4-6 available (none is using more than the 2 Gigabit ports right now). IPv6 I want to get an IPv6 prefix from our ISP. So at least every "server" has at least one IPv6 interface. We'll still need to keep the IPv4 addressees up and available for legacy clients (web servers and email at the very least). We have two IP networks right now. Adding the public IPv6 address would make it three. Just use IPv6? I'm thinking about just dumping the private IPv4 range and using the IPv6 range as the primary means of all communications. If an interface starts reaching its capacity, utilize the newly free interfaces to create a trunk. It has the advantage that if either the public or private traffic needs to exceed 1Gbps. The traffic for each interface is already analyzed on a regular basis to predict future bandwidth use. In the rare instances where bandwidth unexpected peaks: utilize QoS to ensure traffic (like our limited SSH access) is prioritized correctly so the problem can be corrected (if possible, our WAN is the bottleneck right now). It also has the advantage of not needing to make an entry for every private address. We may have private DNS (or just LDAP), but it'll be much more limited in scope with less entries to duplicate. Summary I'm trying to make this network as "simple" as possible. At the same time, I want to make sure its reliable, upgradeable, scalable, and (eventually) redundant. Having one IPv6 network, and a legacy IPv4 network seems to be the best solution to me. Regarding using assigned IPv6 addresses for both networks, sharing the available bandwidth on one (more trunked if needed): Are there any technical disadvantages (limitations, buffers, scalability)? Are there any other security considerations (asides from firewalls mentioned above) to consider? Are there regulations or other security requirements (like PCI-DSS) that this doesn't meet? Is there typical software for setting up a Linux network that doesn't have IPv6 support yet? (logging, ldap, puppet) Some other thing I didn't consider?

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• Soapi.CS : A fully relational fluent .NET Stack Exchange API client library

  - by Sky Sanders

  Soapi.CS for .Net / Silverlight / Windows Phone 7 / Mono as easy as breathing...: var context = new ApiContext(apiKey).Initialize(false); Question thisPost = context.Official .StackApps .Questions.ById(386) .WithComments(true) .First(); Console.WriteLine(thisPost.Title); thisPost .Owner .Questions .PageSize(5) .Sort(PostSort.Votes) .ToList() .ForEach(q=> { Console.WriteLine("\t" + q.Score + "\t" + q.Title); q.Timeline.ToList().ForEach(t=> Console.WriteLine("\t\t" + t.TimelineType + "\t" + t.Owner.DisplayName)); Console.WriteLine(); }); // if you can think it, you can get it. Output Soapi.CS : A fully relational fluent .NET Stack Exchange API client library 21 Soapi.CS : A fully relational fluent .NET Stack Exchange API client library Revision code poet Revision code poet Votes code poet Votes code poet Revision code poet Revision code poet Revision code poet Votes code poet Votes code poet Votes code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Votes code poet Comment code poet Revision code poet Votes code poet Revision code poet Revision code poet Revision code poet Answer code poet Revision code poet Revision code poet 14 SOAPI-WATCH: A realtime service that notifies subscribers via twitter when the API changes in any way. Votes code poet Revision code poet Votes code poet Comment code poet Comment code poet Comment code poet Votes lfoust Votes code poet Comment code poet Comment code poet Comment code poet Comment code poet Revision code poet Comment lfoust Votes code poet Revision code poet Votes code poet Votes lfoust Votes code poet Revision code poet Comment Dave DeLong Revision code poet Revision code poet Votes code poet Comment lfoust Comment Dave DeLong Comment lfoust Comment lfoust Comment Dave DeLong Revision code poet 11 SOAPI-EXPLORE: Self-updating single page JavaSript API test harness Votes code poet Votes code poet Votes code poet Votes code poet Votes code poet Comment code poet Revision code poet Votes code poet Revision code poet Revision code poet Revision code poet Comment code poet Revision code poet Votes code poet Comment code poet Question code poet Votes code poet 11 Soapi.JS V1.0: fluent JavaScript wrapper for the StackOverflow API Comment George Edison Comment George Edison Comment George Edison Comment George Edison Comment George Edison Comment George Edison Answer George Edison Votes code poet Votes code poet Votes code poet Votes code poet Revision code poet Revision code poet Answer code poet Comment code poet Revision code poet Comment code poet Comment code poet Comment code poet Revision code poet Revision code poet Votes code poet Votes code poet Votes code poet Votes code poet Comment code poet Comment code poet Comment code poet Comment code poet Comment code poet 9 SOAPI-DIFF: Your app broke? Check SOAPI-DIFF to find out what changed in the API Votes code poet Revision code poet Comment Dennis Williamson Answer Dennis Williamson Votes code poet Votes Dennis Williamson Comment code poet Question code poet Votes code poet About A robust, fully relational, easy to use, strongly typed, end-to-end StackOverflow API Client Library. Out of the box, Soapi provides you with a robust client library that abstracts away most all of the messy details of consuming the API and lets you concentrate on implementing your ideas. A few features include: A fully relational model of the API data set exposed via a fully 'dot navigable' IEnumerable (LINQ) implementation. Simply tell Soapi what you want and it will get it for you. e.g. "On my first question, from the author of the first comment, get the first page of comments by that person on any post" my.Questions.First().Comments.First().Owner.Comments.ToList(); (yes this is a real expression that returns the data as expressed!) Full coverage of the API, all routes and all parameters with an intuitive syntax. Strongly typed Domain Data Objects for all API data structures. Eager and Lazy Loading of 'stub' objects. Eager\Lazy loading may be disabled. When finer grained control of requests is desired, the core RouteMap objects may be leveraged to request data from any of the API paths using all available parameters as documented on the help pages. A rich Asynchronous implementation. A configurable request cache to reduce unnecessary network traffic and to simplify your usage logic. There is no need to go out of your way to be frugal. You may set a distinct cache duration for any particular route. A configurable request throttle to ensure compliance with the api terms of usage and to simplify your code in that you do not have to worry about and respond to 50X errors. The RequestCache and Throttled Queue are thread-safe, so can make as many requests as you like from as many threads as you like as fast as you like and not worry about abusing the api or having to write reams of management/compensation code. Configurable retry threshold that will, by default, make up to 3 attempts to retrieve a request before failing. Every request made by Soapi is properly formed and directed so most any http error will be the result of a timeout or other network infrastructure. A retry buffer provides a level of fault tolerance that you can rely on. An almost identical javascript library, Soapi.JS, and it's full figured big brother, Soapi.JS2, that will enable you to leverage your server cycles and bandwidth for only those tasks that require it and offload things like status updates to the client's browser. License Licensed GPL Version 2 license. Why is Soapi.CS GPL? Can I get an LGPL license for Soapi.CS? (hint: probably) Platforms .NET 3.5 .NET 4.0 Silverlight 3 Silverlight 4 Windows Phone 7 Mono Download Source code lives @ http://soapics.codeplex.com. Binary releases are forthcoming. codeplex is acting up again. get the source and binaries @ http://bitbucket.org/bitpusher/soapi.cs/downloads The source is C# 3.5. and includes projects and solutions for the following IDEs Visual Studio 2008 Visual Studio 2010 ModoDevelop 2.4 Documentation Full documentation is available at http://soapi.info/help/cs/index.aspx Sample Code / Usage Examples Sample code and usage examples will be added as answers to this question. Full API Coverage all API routes are covered Full Parameter Parity If the API exposes it, Soapi giftwraps it for you. Building a simple app with Soapi.CS - a simple app that gathers all traces of a user in the whole stackiverse. Fluent Configuration - Setting up a Soapi.ApiContext could not be easier Bulk Data Import - A tiny app that quickly loads a SQLite data file with all users in the stackiverse. Paged Results - Soapi.CS transparently handles multi-page operations. Asynchronous Requests - Soapi.CS provides a rich asynchronous model that is especially useful when writing api apps in Silverlight or Windows Phone 7. Caching and Throttling - how and why Apps that use Soapi.CS Soapi.FindUser - .net utility for locating a user anywhere in the stackiverse Soapi.Explore - The entire API at your command Soapi.LastSeen - List users by last access time Add your app/site here - I know you are out there ;-) if you are not comfortable editing this post, simply add a comment and I will add it. The CS/SL/WP7/MONO libraries all compile the same code and with the exception of environmental considerations of Silverlight, the code samples are valid for all libraries. You may also find guidance in the test suites. More information on the SOAPI eco-system. Contact This library is currently the effort of me, Sky Sanders (code poet) and can be reached at gmail - sky.sanders Any who are interested in improving this library are welcome. Support Soapi You can help support this project by voting for Soapi's Open Source Ad post For more information about the origins of Soapi.CS and the rest of the Soapi eco-system see What is Soapi and why should I care?

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• AdvancedFormatProvider: Making string.format do more

  - by plblum

  When I have an integer that I want to format within the String.Format() and ToString(format) methods, I’m always forgetting the format symbol to use with it. That’s probably because its not very intuitive. Use {0:N0} if you want it with group (thousands) separators. text = String.Format("{0:N0}", 1000); // returns "1,000"   int value1 = 1000; text = value1.ToString("N0"); Use {0:D} or {0:G} if you want it without group separators. text = String.Format("{0:D}", 1000); // returns "1000"   int value2 = 1000; text2 = value2.ToString("D"); The {0:D} is especially confusing because Microsoft gives the token the name “Decimal”. I thought it reasonable to have a new format symbol for String.Format, "I" for integer, and the ability to tell it whether it shows the group separators. Along the same lines, why not expand the format symbols for currency ({0:C}) and percent ({0:P}) to let you omit the currency or percent symbol, omit the group separator, and even to drop the decimal part when the value is equal to the whole number? My solution is an open source project called AdvancedFormatProvider, a group of classes that provide the new format symbols, continue to support the rest of the native symbols and makes it easy to plug in additional format symbols. Please visit https://github.com/plblum/AdvancedFormatProvider to learn about it in detail and explore how its implemented. The rest of this post will explore some of the concepts it takes to expand String.Format() and ToString(format). AdvancedFormatProvider benefits: Supports {0:I} token for integers. It offers the {0:I-,} option to omit the group separator. Supports {0:C} token with several options. {0:C-$} omits the currency symbol. {0:C-,} omits group separators, and {0:C-0} hides the decimal part when the value would show “.00”. For example, 1000.0 becomes “$1000” while 1000.12 becomes “$1000.12”. Supports {0:P} token with several options. {0:P-%} omits the percent symbol. {0:P-,} omits group separators, and {0:P-0} hides the decimal part when the value would show “.00”. For example, 1 becomes “100 %” while 1.1223 becomes “112.23 %”. Provides a plug in framework that lets you create new formatters to handle specific format symbols. You register them globally so you can just pass the AdvancedFormatProvider object into String.Format and ToString(format) without having to figure out which plug ins to add. text = String.Format(AdvancedFormatProvider.Current, "{0:I}", 1000); // returns "1,000" text2 = String.Format(AdvancedFormatProvider.Current, "{0:I-,}", 1000); // returns "1000" text3 = String.Format(AdvancedFormatProvider.Current, "{0:C-$-,}", 1000.0); // returns "1000.00" The IFormatProvider parameter Microsoft has made String.Format() and ToString(format) format expandable. They each take an additional parameter that takes an object that implements System.IFormatProvider. This interface has a single member, the GetFormat() method, which returns an object that knows how to convert the format symbol and value into the desired string. There are already a number of web-based resources to teach you about IFormatProvider and the companion interface ICustomFormatter. I’ll defer to them if you want to dig more into the topic. The only thing I want to point out is what I think are implementation considerations. Why GetFormat() always tests for ICustomFormatter When you see examples of implementing IFormatProviders, the GetFormat() method always tests the parameter against the ICustomFormatter type. Why is that? public object GetFormat(Type formatType) { if (formatType == typeof(ICustomFormatter)) return this; else return null; } The value of formatType is already predetermined by the .net framework. String.Format() uses the StringBuilder.AppendFormat() method to parse the string, extracting the tokens and calling GetFormat() with the ICustomFormatter type. (The .net framework also calls GetFormat() with the types of System.Globalization.NumberFormatInfo and System.Globalization.DateTimeFormatInfo but these are exclusive to how the System.Globalization.CultureInfo class handles its implementation of IFormatProvider.) Your code replaces instead of expands I would have expected the caller to pass in the format string to GetFormat() to allow your code to determine if it handles the request. My vision would be to return null when the format string is not supported. The caller would iterate through IFormatProviders until it finds one that handles the format string. Unfortunatley that is not the case. The reason you write GetFormat() as above is because the caller is expecting an object that handles all formatting cases. You are effectively supposed to write enough code in your formatter to handle your new cases and call .net functions (like String.Format() and ToString(format)) to handle the original cases. Its not hard to support the native functions from within your ICustomFormatter.Format function. Just test the format string to see if it applies to you. If not, call String.Format() with a token using the format passed in. public string Format(string format, object arg, IFormatProvider formatProvider) { if (format.StartsWith("I")) { // handle "I" formatter } else return String.Format(formatProvider, "{0:" + format + "}", arg); } Formatters are only used by explicit request Each time you write a custom formatter (implementer of ICustomFormatter), it is not used unless you explicitly passed an IFormatProvider object that supports your formatter into String.Format() or ToString(). This has several disadvantages: Suppose you have several ICustomFormatters. In order to have all available to String.Format() and ToString(format), you have to merge their code and create an IFormatProvider to return an instance of your new class. You have to remember to utilize the IFormatProvider parameter. Its easy to overlook, especially when you have existing code that calls String.Format() without using it. Some APIs may call String.Format() themselves. If those APIs do not offer an IFormatProvider parameter, your ICustomFormatter will not be available to them. The AdvancedFormatProvider solves the first two of these problems by providing a plug-in architecture.

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• Visiting the Emtel Data Centre

  Back in February at the first event of the Emtel Knowledge Series (EKS) I spoke to various people at Emtel about their data centre here on the island. I was trying to see whether it would be possible to arrange a meeting over there for a selected group of our community members. Well, let's say it like this... My first approach wasn't that promising and far from successful but during the following months there were more and more occasions to get in touch with the "right" contact persons at Emtel to make it happen... Setting up an appointment and pre-requisites The major improvement came during a Boot Camp for Windows Phone 8.1 App development organised by Microsoft Indian Ocean Islands in cooperation with Emtel at the Emtel World, Ebene. Apart from learning bits and pieces regarding Universal Apps I took the opportunity to get in touch with Arvin Lockee, Sales Executive - Data, during our lunch break. And this really kicked off the whole procedure. Prior to get access to the Emtel data centre it is requested that you provide full name and National ID of anyone going to visit. Also, it should be noted that there was only a limited amount of seats available. Anyways, packed with this information I posted through the usual social media channels. Responses came in very quickly and based on First-come, first-serve (FCFS) principle I noted down the details and forwarded them to Emtel in order to fix a date and time for the visit. In preparation on our side, all attendees exchanged contact details and we organised transport options to go to the data centre in Arsenal. The day before and on the day of our meeting, Arvin send me a reminder to check whether everything is still confirmed and ready to go... Of course, it was! Arriving at the Emtel Data Centre As I'm coming from Flic En Flac towards the North, we agreed that I'm going to pick up a couple of young fellows near the old post office in Port Louis. All went well, except that Sean eventually might be living in another time zone compared to the rest of us. Anyway, after some extended stop we were complete and arrived just in time in Arsenal to meet and greet with Ish and Veer. Again, Emtel is taking access procedures to their data centre very serious and the gate stayed close until all our IDs had been noted and compared to the list of registered attendees. Despite having a good laugh at the mixture of old and new ID cards it was a straight-forward processing. The ward was very helpful and guided us to the waiting area at the entrance section of the building. Shortly after we were welcomed by Kamlesh Bokhoree, the Data Centre Officer. He gave us brief introduction into the rules and regulations during our visit, like no photography allowed, not touching the buttons, and following his instructions through the whole visit. Of course! Inside the data centre Next, he explained us the multi-factor authentication system using a combination of bio-metric data, like finger print reader, and "classic" pin panel. The Emtel data centre provides multiple services and next to co-location for your own hardware they also offer storage options for your backup and archive data in their massive, fire-resistant vault. Very impressive to get to know about the considerations that have been done in choosing the right location and how to set up the whole premises. It should also be noted that there is 24/7 CCTV surveillance inside and outside the buildings. Strengths of the Emtel TIER 3 Data Centre, Mauritius Finally, we were guided into the first server room. And wow, the whole setup is cleverly planned and outlined in the architecture. From the false floor and ceilings in order to provide optimum air flow, over to the separation of cold and hot aisles between the full-size server racks, and of course the monitored air conditions in order to analyse and watch changes in temperature, smoke detection and other parameters. And not surprisingly everything has been implemented in two independent circuits. There is a standardised classification for the construction and operation of data centres world-wide, and the Emtel's one has been designed to be a TIER 4 building but due to the lack of an alternative power supplier on the island it is officially registered as a TIER 3 compliant data centre. Maybe in the long run there might be a second supplier of energy next to CEB... time will tell. Luckily, the data centre is integrated into the National Fibre Optic Gigabit Ring and Emtel already connects internationally through diverse undersea cable routes like SAFE & LION/LION2 out of Mauritius and through several other providers for onwards connectivity. The data centre is part of the National Fibre Optic Gigabit Ring and has redundant internet connectivity onwards. Meanwhile, Arvin managed to join our little group of geeks and he supported Kamlesh in answering our technical questions regarding the capacities and general operation of the data centre. Visiting the NOC and its dedicated team of IT professionals was surely one of the visual highlights. Seeing their wall of screens to monitor any kind of activities on the data lines, the managed servers and the activity in and around the building was great. Even though I'm using a multi-head setup since years I cannot keep it up with that setup... ;-) But I got a couple of ideas on how to improve my work spaces here at the office. Clear advantages of hosting your e-commerce and mobile backends locally After the completely isolated NOC area we continued our Q&A session with Kamlesh and Arvin in the second server room which is dedictated to shared environments. On first thought it should be well-noted that there is lots of space for full-sized racks and therefore co-location of your own hardware. Actually, given the feedback that there will be upcoming changes in prices the facilities at the Emtel data centre are getting more and more competitive and interesting for local companies, especially small and medium enterprises. After seeing this world-class infrastructure available on the island, I'm already considering of moving one of my root servers abroad to be co-located here on the island. This would provide an improved user experience in terms of site performance and latency. This would be a good improvement, especially for upcoming e-commerce solutions for two of my local clients. Later on, we actually started the conversation of additional services that could be a catalyst for the local market in order to attract more small and medium companies to take the data centre into their evaluations regarding online activities. Until today Emtel does not provide virtualised server environments but there might be ongoing plans in the future to cover this field as well. Emtel is a mobile operator and internet connectivity provider in the first place, entering a market of managed and virtualised server infrastructures including capacities in terms of cloud storage and computing are rather new and there is a continuous learning curve at Emtel, too. You cannot just jump into a new market and see how it works out... And I appreciate Emtel's approach towards a solid fundament and then building new services on top of that. Emtel as a future one-stop-shop service provider for all your internet and telecommunications needs. Emtel's promotional video about their TIER 3 data centre in Arsenal, Mauritius More details are thoroughly described in Emtel's brochure of their data centre. Check out their PDF document here. Thanks for this opportunity Visiting and walking through the Emtel data centre for more than 2 hours was a great experience. As representative of the Mauritius Software Craftsmanship Community (MSCC) I would like to thank anyone at Emtel involved in the process of making it happen, and especially to Arvin Lockee and Kamlesh Bokhoree for their time and patience in explaining the infrastructure and answering all the endless questions from our members. Thank You!

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