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  • Would You Swim Laps in Lake Baikal?

    - by rickramsey
    source This is the lake where Yuli Vasiliev's countrymen swim laps. Yuli is one of my favorite OTN writers not just because he really knows his stuff. Not just because his writing is clear and accurate. And not just because his English is better than the English of most native speakers. Yo, those are all good reasons. But it's the Lake Baikal thing. Yuli recently wrote two wicked good how-to's about Oracle VM Templates. You should read them. You might gain a gram of Yuli's respect. Two grams, if you can head butt icebergs while you swim. How to Use Oracle VM Templates How to prepare an Oracle VM environment to use Oracle VM Templates, how to obtain a template, and how to deploy the template to your Oracle VM environment. Also how to create a virtual machine based on that template and how you can clone the template and change the clone's configuration. How to Use Oracle VM VirtualBox Templates How to use Oracle VM VirtualBox Templates in Oracle VM VirtualBox. Similar to the article above, but it describes how to download, install, and configure the templates within Oracle VM VirtualBox, instead of on bare metal. Other OTN Technical Articles by Yuli Vasiliev Retrieving, Transforming, and Consolidating Web Data with Oracle Database Setting Up, Configuring, and Using a WebLogic Server Cluster Cube Development for Beginners How to XQuery Non-JDBC Sources from JDBC Advanced Dimensional Design with Oracle Warehouse Builder Using the JDBC Connectivity Layer in Oracle Warehouse Builder High Performance Oracle JDBC Programming Python Data Persistence with Oracle Querying JPA Entities with JPQL and Native SQL - Rick Website Newsletter Facebook Twitter

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  • How to analyze data

    - by Subhash Dike
    We are working on an application that allows user to search/read some content in a particular domain. We wanted to add some capability in the app which can suggest user some content based on the usage pattern (analyze data based on frequency and relevance). Currently every time user search or read something we do store that information in backend database. We would like to use this data to present some additional content to user. Could someone explain what kind of tools will be required for such a job and any example? And what this concept is called, data analysis? data mining? business intelligence? or something else? Update: Sorry for being too broad, here is an example SQL Database (Just to give an idea, actual db is little different with normalization and stuff) Table: UserArticles Fields: UserName | ArticleId | ArticleTitle | DateVisited | ArticleCategory Table: CategoryArticles Fields: Category | Article Title | Author etc. One Category may have one more articles. One user may have read the same article multiple times (in this case we place additional entry in the user article table. Task: Use the information availabel in UserArticle table and rank categories in order which would be presented to user automatically in other part of application. Factors to be considered are frequency and recency. This might be possible through simple queries or may require specialized tools. Either way, the task is what mention above. I am not too sure which route to take, hence the question. Thoughts??

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  • SSAS Compare version 1.0 released

    - by Red Gate Software BI Tools Team
    We’re pleased to announce that SSAS Compare version 1.0 has been released as a free tool. Version 1.0 includes: Comparisons of live databases and XMLA or Analysis Services Project files MDX syntax diffs and highlighting Server comparisons Deployment wizard with summaries of scripted actions Bug fixes and engine and UI refinements We’ve tested it on as many cube configurations as we could find (not just good old AdventureWorks!), but we can’t provide support for free tools — so if you’re reliant on SSAS Compare for your cube deployment, use it at your own risk. See the user license agreement in the installer for more details. SSAS Compare’s come a long way from its humble beginnings as an internal tool first developed for Red Gate’s own BI developers. Today’s SSAS Compare is now much more stable — not to mention much easier to use — and something the team is proud to have released with Red Gate’s name on. Next: Deployment Manager We’re working on integrating SSAS Compare cube deployment with our new Deployment Manager tool, so you’ll be able to create cube deployment scripts and automate the deployment process, too.  We’re documenting the process in a white paper we’ll publish online in the next week. Thank you! Thanks to all the SSAS Compare users out there. Without your feedback, we could never have produced such a stable product so quickly. We hope you continue to find useful. See you in Deployment Manager!  

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  • good literature for teaching object oriented thinking in C [closed]

    - by Dipan Mehta
    Quite often C is the primary platform for the development. And when things are large scale, I have seen partitioning of the system as different objects is quite a natural thing. Some or many of the object orientated analysis and design principles are used here very well. This is not a debate question about whether or not C is a good candidate for object oriented programming or not. This is also NOT a question how to do OO in C. You can refer to this question and there are probably many such citations. As far as I am concerned, I have learned some of this things while working with many open source and commercial projects. (libjpeg, ffmpeg, Gstreamer which is based on GObject). I can probably extend a few references that explains some of these concepts such as - 1. Event Helix article, 2. Linux Mag article 3. one of my answers which links Schreiner's reference. Unfortunately, when we induct younger folks, it seems too hard to make them learn all of it the hard way. Usually, when we say it's C, a general reaction is to throw away all of the "Object thinking". Looking for help extending above references from those who have been in the similar areas of work. Are there any good formal literature that explains how Object thinking can be made to use while you are working in C? I have seen tons of book on general "object oriented paradigms" but they all focus on advanced languages mostly not in C. You see most C books - but most focus only on the syntax and the obfuscated corners of C and that's it. There are hardly ANY good reference, specially books or any systematic (I mean formal) literature on how to apply OO in C. This is very surprising given that so many large scale open source projects use C which are truly using this very well; but we hardly see any good formal literature on this subject.

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  • TODO Formatting

    - by charlie.mott
    Article Source: http://geekswithblogs.net/charliemott TODO's should only be used for a short period of time to remind you that something needs to be done. They should then be addressed as soon as possible. In order to know who owns a TODO task and how long it’s been outstanding, my company uses the following standard for TODO formatting: Format:     // TODO : Owner Initials – Date Created – Description of task. Sample:     // TODO: CM – 2012/01/20 – Move this class to a new location so it can be reused. Using this pattern makes it easy to use the Resharper TODO explorer. The Carrot In order to make it easy for developers to apply this rule, a code snippet can be created in Visual Studio. Even better, I created a Resharper template. This gives the facility to use the current user name and current date macros. image This actually makes the formatting look like this. Sample:     // TODO: cmott – 2012/01/20 – Move this class to a new location so it can be reused. The Stick How to you enforce such a rule? I tried to create a custom Resharper Highlighting Pattern to perform custom code analysis inspection for deviations from this pattern. However, I did not have any success. The find dialog would not accept // text. If I work it out, I will update this blog post. StyleCop Instead I created a custom StyleCop rule. I followed the approach used with the StyleCop Contrib project. This provides a simple to use base class and easy to use unit testing framework. I will upload this todo format analyzer as a patch to that project. image

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  • Logarithmic spacing of FFT subbands

    - by Mykel Stone
    I'm trying to do the examples within the GameDev.net Beat Detection article ( http://archive.gamedev.net/archive/reference/programming/features/beatdetection/index.html ) I have no issue with performing a FFT and getting the frequency data and doing most of the article. I'm running into trouble though in the section 2.B, Enhancements and beat decision factors. in this section the author gives 3 equations numbered R10-R12 to be used to determine how many bins go into each subband: R10 - Linear increase of the width of the subband with its index R11 - We can choose for example the width of the first subband R12 - The sum of all the widths must not exceed 1024 He says the following in the article: "Once you have equations (R11) and (R12) it is fairly easy to extract 'a' and 'b', and thus to find the law of the 'wi'. This calculus of 'a' and 'b' must be made manually and 'a' and 'b' defined as constants in the source; indeed they do not vary during the song." However, I cannot seem to understand how these values are calculated...I'm probably missing something simple, but learning fourier analysis in a couple of weeks has left me Decimated-in-Mind and I cannot seem to see it.

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  • How do I create my own programming language and a compiler for it

    - by Dave
    I am thorough with programming and have come across languages including BASIC, FORTRAN, COBOL, LISP, LOGO, Java, C++, C, MATLAB, Mathematica, Python, Ruby, Perl, Javascript, Assembly and so on. I can't understand how people create programming languages and devise compilers for it. I also couldn't understand how people create OS like Windows, Mac, UNIX, DOS and so on. The other thing that is mysterious to me is how people create libraries like OpenGL, OpenCL, OpenCV, Cocoa, MFC and so on. The last thing I am unable to figure out is how scientists devise an assembly language and an assembler for a microprocessor. I would really like to learn all of these stuff and I am 15 years old. I always wanted to be a computer scientist some one like Babbage, Turing, Shannon, or Dennis Ritchie. I have already read Aho's Compiler Design and Tanenbaum's OS concepts book and they all only discuss concepts and code in a high level. They don't go into the details and nuances and how to devise a compiler or operating system. I want a concrete understanding so that I can create one myself and not just an understanding of what a thread, semaphore, process, or parsing is. I asked my brother about all this. He is a SB student in EECS at MIT and hasn't got a clue of how to actually create all these stuff in the real world. All he knows is just an understanding of Compiler Design and OS concepts like the ones that you guys have mentioned (ie like Thread, Synchronisation, Concurrency, memory management, Lexical Analysis, Intermediate code generation and so on)

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  • How to document requirements for an API systematically?

    - by Heinrich
    I am currently working on a project, where I have to analyze the requirements of two given IT systems, that use cloud computing, for a Cloud API. In other words, I have to analyze what requirements these systems have for a Cloud API, such that they would be able to switch it, while being able to accomplish their current goals. Let me give you an example for some informal requirements of Project A: When starting virtual machines in the cloud through the API, it must be possible to specify the memory size, CPU type, operating system and a SSH key for the root user. It must be possible to monitor the inbound and outbound network traffic per hour per virtual machine. The API must support the assignment of public IPs to a virtual machine and the retrieval of the public IPs. ... In a later stage of the project I will analyze some Cloud Computing standards that standardize cloud APIs to find out where possible shortcomings in the current standards are. A finding could and will probably be, that a certain standard does not support monitoring resource usage and thus is not currently usable. I am currently trying to find a way to systematically write down and classify my requirements. I feel that the way I currently have them written down (like the three points above) is too informal. I have read in a couple of requirements enineering and software architecture books, but they all focus too much on details and implementation. I do really only care about the functionalities provided through the API/interface and I don't think UML diagrams etc. are the right choice for me. I think currently the requirements that I collected can be described as user stories, but is that already enough for a sophisticated requirements analysis? Probably I should go "one level deeper" ... Any advice/learning resources for me?

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  • Application Scope v's Static - Not Quite the same

    - by Duncan Mills
    An interesting question came up today which, innocent as it sounded, needed a second or two to consider. What's the difference between storing say a Map of reference information as a Static as opposed to storing the same map as an application scoped variable in JSF?  From the perspective of the web application itself there seems to be no functional difference, in both cases, the information is confined to the current JVM and potentially visible to your app code (note that Application Scope is not magically propagated across a cluster, you would need a separate instance on each VM). To my mind the primary consideration here is a matter of leakage. A static will be (potentially) visible to everything running within the same VM (OK this depends on which class-loader was used but let's keep this simple), and this includes your model code and indeed other web applications running in the same container. An Application Scoped object, in JSF terms, is much more ring-fenced and is only visible to the Web app itself, not other web apps running on the same server and not directly to the business model layer if that is running in the same VM. So given that I'm a big fan of coding applications to say what I mean, then using Application Scope appeals because it explicitly states how I expect the data to be used and a provides a more explicit statement about visibility and indeed dependency as I'd generally explicitly inject it where it is needed.  Alternative viewpoints / thoughts are, as ever, welcomed...

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  • Need ideas for an innovation week

    - by slandau
    So 4 times a year we have an innovation week (to even out the odd sprint releases). This whole week is dedicated to experimenting with new technology/ideas that could potentially help progress the software department or the company as a whole, and serve as sort of a starting point for new ideas and brainstorming. For example, the last one contained a lot of projects. One was the re-design of our web app into more of a Web 2.0 look and feel using JQuery and a lot of cool CSS tricks. Another was a proposal for a new bug tracking software as opposed to the clearly outdated one we use, and another was a very cool JQuery/Js design that could show the same page to multiple users on different computers and allow each of them to take "charge" of the page, disabling the other one from doing anything, and vice versa, seeing all updates in real time -- sort of like Netmeeting through Js. Well, this is my first one as a new employee so I wanted to think of something cool. We get one week (anywhere from 40-60 hours or so), and we usually pair up or do this in groups of 3-4, depending on how many projects there are. Projects have to get approved but usually that doesn't prove to be too difficult. We are in the financial analysis software industry if the domain was leading you guys to think of anything helpful. I am primarily working on a web app in MVC 2 at the moment using a lot of JQuery and a C# backend. Do you guys have any idea of something that would be cool/beneficial/worth it?

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  • Ubuntu Slow - What architecture does the Windows Installer install?

    - by Benjamin Yep
    I feel absolutely limited by using Windows, and I need to switch to a Unix environment. I once installed Red Hat on my lappie (screen + external monitor setup; 4GB ram; x64; runs fast) and it worked fine, but I saw that the computer cluster that is the birthplace of my unix knowledge switched to Ubuntu, so naturally I follow. To the point. When I installed Ubuntu onto my machine via the Windows Installer, it ran quite slow. Opening Firefox takes about 8-9 seconds, it freezes up often, unable to handle its own background processes. I saw in a thread that, perhaps, it is running slow because the Windows Installer is installing an x64 version. Of course, my computer has had no performance issues in the past(except that time with the trojans but you know, know one is perfect ;) ) Anyways, I uninstalled Ubuntu, freeing up the max allocated memory it took up, and continue to be sad, trapped in my MS world with only a buggy Cygwin, any assistance is greatly appreciated! :) Thanks ~Ben

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  • invitation: Oracle Endeca Information Discovery Bootcamp

    - by mseika
    The Oracle Endeca Information Discovery (OEID) Boot Camp is designed to give partners an understanding of OEID’s features, and how it complements the existing Oracle Business Intelligence suite. Participants will learn how to develop & implement solutions using a Data Discovery method. Training is in EnglishWhat will be covered?The Oracle Endeca Information Discovery (OEID) Boot Camp is a three-day class with a combination of lecture and hands-on exercises, tailored to make participants aware of the Oracle Endeca Information Discovery platform, and to gain valuable skills for the implementation of projects.The course will follow a combination of lectures and hands-on lab sessions, to allow participants to apply the knowledge they have gained by extracting from sample data sources, and creating an end-user application that will be used to answer several business questions. What You Will Learn Architecture: OEID Components, use of graphs, overview of clustering OEID Installation: Architecture planning, infrastructure requirements, installation process, production hints & tips OEID Administration: Data store management, administrative operations, portal configuration, data sources, system monitoring Indexing: Integration Suite, Data source analysis, Graph (ETL) creation, record design techniques Portlets: Studio portlets, custom portlet development, querying functions Reporting: Studio applications & best practices, visualizations, EQL PrerequisitesYou must bring a laptop with you for the Hands-on labs ENVIRONMENT – LAPTOP REQUIREMENTS For the OEID boot camp, participants will perform the hands-on lab exercises using a virtual machine image. These virtual machines will be provided to participants within a cloud environment, requiring participants to bring a laptop to the Boot Camp that can access a Windows server utilizing Microsoft RDP from their laptop. Participants will not need to install any software onto their laptops, but must ensure that they have the proper software installed for their OS, to connect through RDP to a server. HARDWARE • CPU: Dual-core, x64, 1.8Ghz or higher • RAM: 2GB SOFTWARE • Microsoft Remote Desktop Client • Internet Explorer 7, Firefox, or Google Chrome This boot camp is intended for prospective implementers of Oracle Endeca Information Discovery (OEID), or those in a presales role looking to gain insight into the technical benefits of this new package. Attendees should have experience and familiarity with the basic concepts of business intelligence. Where and When ? Monday, October 15th until wednesday, October 17th included 9:00 - 18:00 Oracle France 15, boulevard Charles de Gaulle 92715 Colombes Access Register Here Limited number of seats !

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  • Is it better to specialize in a single field I like, or expand into other fields to broaden my horizons?

    - by Oak
    This is a dilemma about which I have been thinking for quite a while. I'm a graduate student and my topics of interest are programming language design, code analysis, compilation, etc. So far, this field has been very interesting and rewarding for me, so I was thinking about finding a job in that field and continuing to specialize in it. I feel like it's a relatively solid field which won't "get out of style" anytime soon. I've always thought that in such complex fields it's better to be a real expert than just another guy who superficially understand what the experts are talking about. On the other hand, I feel that by specializing this way I really limit my future option. I have always been a strong believer in multidisciplinary approaches to problems. Maybe I should go search for a general programming job in which I could gain experience in other fields, as well as occasionally apply my favorite field for solving problems. Specializing in only one or two fields can prevent me from thinking outside the box and cause stagnation. I would really like to hear more opinions about this choice. The truth is I'm already leaning towards one of the choices, so basic psychology says nothing will change my mind, but I would still love to hear some feedback.

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  • "Unable to install GRUB in /dev/sda" when installing GRUB

    - by vicban3d
    I recently bought a shiny new Lenovo Yoga 2 Pro and I want to dual boot it with Ubuntu for studying purposes. Its built-in OS is Windows 8.1 and it has a 256GB SSD. I've made a separate 90GB partition just for Ubuntu and a live USB to install it. The first time everything seemed to work great, I solved the wifi issued by blacklisting ideapad_laptop, the installation went flawlessly and Ubuntu worked fine. When I got up the next morning and turned on my laptop it booted into Windows right away without ever showing the GRUB menu. So I tried to reset, and checked my partitions with the Disk Manager and everything looked fine. Since I couldn't find a solution online I went ahead and formatted the partition to try and install again. This time and every time since, the installation was aborted and I got a fatal error saying: Unable to install GRUB in /dev/sda Executing `grub-install /dev/sda` failed. This is a fatal error. Can anyone please suggest a solution to this problem? If any further information is needed I would be happy to provide it. Thanks. When installing I get the following in details: ubuntu kernel: [ 1946.372741] FAT-fs (sda2): error, fat_get_cluster: invalid cluster chain (i_pos 0). ubuntu grub-installer: error: Running 'grub-install --force failed.

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  • Where I'll Be At JavaOne 2012

    - by Geertjan
    Fun and games for me at JavaOne 2012. Below are the sessions/BOFs/tutorials I'll be attending. The items in red are the sessions and BOFs where I'll be speaking, either as the main/only speaker or as a supporting speaker in someone else's presentation, while the other items (except for the NetBeans booth duties and mini presentations, which are included below) are items I'm interested in and so will be sitting in the audience: Sunday: NetBeans Day Monday: 10:00 - 12:00 TUT4801: Make Your Clients Richer: JavaFX and the NetBeans Platform 12:20 - 12:30 Mini Presentation in OTN Lounge: What's New in NetBeans IDE? 13:00 - 14:00 CON7050: How My Life Would Have Been So Much Better If We Had Used the NetBeans Platform 14:30 - 14:40 Mini Presentation in OTN Lounge: NetBeans and Java EE 15:00 - 16:00 CON4038: Project EASEL: Developing and Managing HTML5 in a Java World 16:30 - 17:15 BOF6151: NetBeans.Next: The Roadmap Ahead 17:30 - 18:15 BOF3332: Lessons Learned in Writing a PDF-to-JavaFX Converter for NetBeans 18:30 - 19:15 BOF4920: Runtime Class Reloading for Dummies Tuesday: 9:30 - 11:30 NetBeans Booth 11:30 - 12:30 CON6139: Lessons Learned in Building Enterprise and Desktop Applications with the NetBeans IDE 13:00 - 14:00 CON4387: Bringing Mylyn to NetBeans and OSGi, Bridging Their Worlds 14:30 - 14:40 Mini Presentation in OTN Lounge: NetBeans Java Editor 15:30 - 17:30 NetBeans Booth 17:30 - 18:15 BOF3665: Custom Static Code Analysis 18:30 - 19:15 BOF5806: Doing JSF Development in the NetBeans IDE  Wednesday: 8:30 - 9:30 CON5132: NetBeans Plug-in Development: JRebel Experience Report 10:00 - 11:00 CON2987: Unlocking the Java EE 6 Platform 11:30 - 12:30 CON10140: Delivering Bug-Free, More Efficient Code for the Java Platform 13:00 - 14:00 CON3826: Patterns for Modularity: What Modules Don’t Want You to Know 14:30 - 14:40 Mini Presentation in OTN Lounge: NetBeans Platform 15:00 - 16:00 CON3160: Dynamic Class Reloading in the Wild with Javeleon Thursday: 12:30 - 13:30 CON4952: NetBeans Platform Panel Discussion 14:00 - 15:00 CON11879: Getting Started with the NetBeans Platform There are several sessions/BOFs I would have liked to be able to attend, but because of clashes with other sessions that I need to see slightly more urgently, I won't be able to attend those, unfortunately. Will be a busy but interesting time, as always! The entire list of NetBeans-oriented sessions can be found here: http://netbeans.org/community/articles/javaone/2012/index.html

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  • Usual Suspects: Typical 3rd Party Entities in E-Commerce [closed]

    - by zharvey
    I am doing some requirements/analysis for a web app that I'd like to build (Ruby/Java developer here). This web app would have a store front, shopping cart and would need to be totally compliant with all e-com best practices. It's amazing how much non-technical info comes up when you search for phrases like "how does e-commerce work", but very little comes up in the way of technical details. As such, I'm having extreme frustration finding answers to what I consider pretty straight-forward questions. I came here because I believe this question is not off-topic; if it is, please leave a comment as to why this question does not belong here and I will happily remove it myself (upvotes if your comment can point me to the correct place for this question!). So then: What 3rd parties will I need to work with to have a modern, web-compliant e-com site? So far I can account for a payment gateway provider like Authorize.net and an SSL certificate provider like Trustwave. Any others? What other standards besides PCI compliance will I be held to (besides governing laws, of course!)? Vulnerability scans: PCI compliance requires quarterly scans: if I'm a "Level 4" (low volume) Merchant does that still apply to me? Irregardless, my backend architecture is quite huge, with web servers, app servers, database, message brokers and more. Do each of these servers need to be scanned?!? If not what servers do need to get these quarterly scans? I usually hate to ask micro-questions inside of one large one, but these are so closely-related I just felt like asking them all separately would be spamming the site with too many petty questions. Thanks in advance!

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  • How to distinguish doc, ppt, xls files, without looking at file extension

    - by Shelby. S
    So I was wondering how would you differentiate ppt, xls and doc files from each other in linux regardless of extensions. I tried 'file' but from the looks of it, all of MSOffice files are categorized under the same file type. Similarly I'm having trouble with docx, xlsx and pptx files, since they're essentially all zip files containing a bunch of xml. I also tried a python script importing the magic module, but no go. I'm trying to identify the actual file for a sandbox analysis. And for this specific purpose I need to find the actual file type in order to run it in the sandbox vm (the Windows vm runs everything by extension). Let's say my sample file is labeled as try.exe, but in reality it's just a doc file. My script will rename it as try.exe.doc, which would work fine for doc files. But since linux identifies all MSOffice files as simple DOC files then there's no way to identify ppt or xls files. As a result the sandbox wont' analyze the sample correctly.

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  • TechEd North America 2012–Day 3 #msTechEd #teched

    - by Marco Russo (SQLBI)
    Yesterday I spent the longest day at this TechEd: we talked with many people at Community Night until 9pm and I have to say that just a few months after Analysis Services 2012 has been released, there are many people already using it. And the adoption of PowerPivot is starting to be quite large. Many new ideas and challenging coming from several different real world scenarios. I was tired but really happy. Alberto presented his Many-to-Many Relationships in BISM Tabular session that was in the same time slot of the BI Power Hour. For this reason, very few people attended Alberto’s session so I think many will watch the recorded session (it should be available within a few days). So what about today? I’ll spend some time at Technical Learning Center area (full schedule here) but the most important event today will be the Querying multi-billion rows with many to many relationships in SSAS Tabular (xVelocity) at the Private Cloud, Public Cloud and Data Platform Theater in the Technical Learning Center area (next to the SQL Server 2012 zone).  Why you should attend? Mainly because you will see live demo over 4 billion rows table with many-to-many relationships involved in complex queries. But for those of you that think this is not enough to attend a 15 minute funny session, well, we’ll give away some 8GB USB Memory Keys to those of you that will guess exact response time of queries before execution. Convinced? Join us at 11:15am and don’t be late, the session will finish at 11:30am! After that, we’ll run a book signing session at the Bookstore at 12:30pm and I will be in the Technical Learning Center area at 3:00pm until 5:00pm. See you there!

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  • Is there a canonical source supporting "all-surrogates"?

    - by user61852
    Background The "all-PK-must-be-surrogates" approach is not present in Codd's Relational Model or any SQL Standard (ANSI, ISO or other). Canonical books seems to elude this restrictions too. Oracle's own data dictionary scheme uses natural keys in some tables and surrogate keys in other tables. I mention this because these people must know a thing or two about RDBMS design. PPDM (Professional Petroleum Data Management Association) recommend the same canonical books do: Use surrogate keys as primary keys when: There are no natural or business keys Natural or business keys are bad ( change often ) The value of natural or business key is not known at the time of inserting record Multicolumn natural keys ( usually several FK ) exceed three columns, which makes joins too verbose. Also I have not found canonical source that says natural keys need to be immutable. All I find is that they need to be very estable, i.e need to be changed only in very rare ocassions, if ever. I mention PPDM because these people must know a thing or two about RDBMS design too. The origins of the "all-surrogates" approach seems to come from recommendations from some ORM frameworks. It's true that the approach allows for rapid database modeling by not having to do much business analysis, but at the expense of maintainability and readability of the SQL code. Much prevision is made for something that may or may not happen in the future ( the natural PK changed so we will have to use the RDBMS cascade update funtionality ) at the expense of day-to-day task like having to join more tables in every query and having to write code for importing data between databases, an otherwise very strightfoward procedure (due to the need to avoid PK colisions and having to create stage/equivalence tables beforehand ). Other argument is that indexes based on integers are faster, but that has to be supported with benchmarks. Obviously, long, varying varchars are not good for PK. But indexes based on short, fix-length varchar are almost as fast as integers. The questions - Is there any canonical source that supports the "all-PK-must-be-surrogates" approach ? - Has Codd's relational model been superceded by a newer relational model ?

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  • Leaving the field of programming. What are the options?

    - by hal10001
    A lot of graduates ask about getting into this field, but I know there are times when I (as well as many others) think about leaving, too. My issue is that I love solving problems and the act of creating something that people enjoy using, and that is what keeps bringing me back. Lately, though, programming has become less of the act of creation and about solving problems, and has become more about being "a monkey at a keyboard". Can you offer any advice with regard to: What fields would offer equivalent problem-solving challenges consistently? How you would go about doing the research, or considering the career change? Basically anything else you think would be helpful in this situation. EDIT: I guess I should clarify and say that I've been in the field about 10 years, and I have had my fair share of working environments. The place where I am at now, and even the previous two jobs, the people I worked with have been great. I've been very lucky in that respect. I'm beginning to wonder if the next step for me has little to do with actual programming and more to do with business analysis or strategic consulting. I would hate to get too much onto the business side of things though, as I like being around tech folks more.

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  • How to do a 3-tier using PHP [closed]

    - by Ric
    I have a requirement from a client for my PHP Web application to be 3-tier. For example, I would have a web server on Apache in the DMZ, but it should NOT contain any DB connections. It should connect to a Middle server that would host the business objects but be behind the firewall. Then those objects connect to my SQL cluster on another server. I have actually done this using .NET, but I am not sure how to setup my stack using PHP. I suppose I could have my UI front tier call the middle tier using REST based web services if I create my middle tier as a second web server, but this seems overly complex. The main reason for this is advanced security: we can not have any passwords on the DMZ first tier web server. The second reason is scalability - to have multiple server on different tiers that can handle the requests. The Last reason is for deployment - it is easier if I can take one set of servers offline for testing before putting them back in production. Is there a open source project that shows how to do this? The only example I can find is the web server hosting files from a shared drive on another machine (kind of how DotNetNuke pretends to be 3-tier), but that is NOT secure.

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  • Is there any simple game that involves psychological factors?

    - by Roman
    I need to find a simple game in which several people need to interact with each other. The game should be simple for an analysis (it should be simple to describe what happens in the game, what players did). Because of the last reason, the video games are not appropriate for my purposes. I am thinking of a simple, schematic, strategic game where people can make a limited set of simple moves. Moreover, the moves of the game should be conditioned not only by a pure logic (like in chess or go). The behavior in the game should depend on psychological factors, on relations between people. In more details, I think it should be a cooperation game where people make their decisions based on mutual trust. It would be nice if players can express punishment and forgiveness in the game. Does anybody knows a game that is close to what I have described above? ADDED I need to add that I need a game where actions of players are simple and easy to formalize. Because of that I cannot use verbal games (where communication between players is important). By simple actions I understand, for example, moves on the board from one position to another one, or passing chips from one player to another one and so on.

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  • Java Components Landing Page and Documentation Updates

    - by joni g.
    The new Java Components page provides access to the documentation for tools that are available for monitoring, managing, and testing Java applications. Documentation for the new versions of the following tools is available: JavaTest Harness 4.6. The JavaTest harness is a general purpose, fully-featured, flexible, and configurable test harness that is suited for most types of unit testing. See the JavaTest tab for documentation. SigTest 3.1. SigTest is a collection of tools that can be used to compare APIs and to measure the test coverage of an API. See the SigTest tab for documentation. The following tools are part of Oracle Java SE Advanced and Oracle Java SE Suite. Java Mission Control and Java Flight Control 5.4 are supported in JDK 8u20. Java Flight Recorder and Java Mission Control together create a complete tool chain to continuously collect low level and detailed runtime information enabling after-the-fact incident analysis. See the JMC tab for documentation. Advanced Management Console 1.0 is a new tool that is now available. AMC can be used to view information about the Java applets and Java Web Start applications running in your enterprise, and create deployment rules and rule sets to manage the execution of these applications. See the AMC tab for documentation. Usage Tracker tracks how Java Runtime Environments (JREs) are being used in your systems. See the Usage Tracker tab for documentation.

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  • How should I create a mutable, varied jtree with arbitrary/generic category nodes?

    - by Pureferret
    Please note: I don't want coding help here, I'm on Programmers for a reason. I want to improve my program planning/writing skills not (just) my understanding of Java. I'm trying to figure out how to make a tree which has an arbitrary category system, based on the skills listed for this LARP game here. My previous attempt had a bool for whether a skill was also a category. Trying to code around that was messy. Drawing out my tree I noticed that only my 'leaves' were skills and I'd labeled the others as categories. Explanation of tree: The Tree is 'born' with a set of hard coded highest level categories (Weapons, Physical and Mental, Medical etc.). Fro mthis the user needs to be able to add a skill. Ultimately they want to add 'One-handed Sword Specialisation' for instance. To do so you'd ideally click 'add' with Weapons selected and then select One-handed from a combobox, then click add again and enter a name in a text field. Then click add again to add a 'level' or 'tier' first proficiency, then specialisation. Of course if you want to buy a different skill it's completely different, which is what I'm having trouble getting my head around let alone programming in. What is a good system for describing this sort of tree in code? All the other JTree examples I've seen have some predictable pattern, and I don't want to have to code this all in 'literals'. Should I be using abstract classes? Interfaces? How can I make this sort of cluster of objects extensible when I add in other skills not listed above that behave differently? If there is not a good system to use, if there a good process for working out how to do this sort of thing?

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  • Advice on choosing a book to read

    - by Kioshiki
    I would like to ask for some recommendations on useful books to read. Initially I had intended on posting quite a long description of my current issue and asking for advice. But I realised that I didn’t have a clear idea of what I wanted to ask. One thing that is clear to me is that my knowledge in various areas needs improving and reading is one method of doing that. Though choosing the right book to read seems like a task in itself when there are so many books out there. I am a programmer but I also deal with analysis, design & testing. So I am not sure what type of book to read. One option might be to work through two books at the same time. I had thought maybe one about design or practices and another of a more technical focus. Recently I came across one book that I thought might be useful to read: http://xunitpatterns.com/index.html It seems like an interesting book, but the comments I read on amazon.co.uk show that the book is probably longer than it needs to be. Has anyone read it and can comment on this? Another book that I already own and would probably be a good one to finish reading is this: http://www.amazon.co.uk/Code-Complete-Practical-Handbook-Construction/dp/0735619670/ref=sr_1_1?ie=UTF8&qid=1309438553&sr=8-1 Has anyone else read this who can comment on its usefulness? Beyond these two I currently have no clear idea of what to read. I have thought about reading a book related to OO design or the GOF design patterns. But I wonder if I am worrying too much about the process and practices and not focusing on the actual work. I would be very grateful for any suggestions or comments. Many Thanks, Kioshiki

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