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Snap App Windows to Pre-Defined Screen Sections with Acer GridVista

- by Asian Angel

The window snapping feature in Windows 7 and the ability to organize monitor(s) into specific gridded sections have both become popular lately. If you love the idea of having both combined in a single software then join us as we look at Acer GridVista. Note: Acer GridVista works with Windows XP, Vista, & 7. It will also work with dual monitors. Setup Acer GridVista comes in a zip file format and at first you might assume that it is portable in nature but it is not. Once you unzip the enclosed folder you will need to double click on “Setup.exe” to install the program. Acer GridVista in Action Once you have installed the program and started it up all that you will notice at first is the new “System Tray Icon”. Here you can see the “Context Menu”… The only menu command that you will likely use most of the time is the “Grid Configuration Command”. Notice that for our single monitor setup that it lists “Display 1”. The “Single Setting” is enabled by default and you can easily choose the layout that best suits your needs. The enabled layout style will always be highlighted in yellow for easy reference. For our example we chose the “Triple (primary at right)” layout style. Each section will be specifically numbered as shown here. Do not worry…the grid and numbers only appear for a moment and then become invisible again until you move an app window into that section/area of your screen. On every regular app window that you open you will notice three new buttons in the upper right corner. Here is what each of these new buttons do: Acer GridVista Extensions (Transparent, Send To Window Grid, About Acer GridVista): Viewable in a drop-down menu Lock To Grid (Enable/Disable): Enabled by default –> Note: Set to disable on a particular window to keep it free of the “grid locking function” Always On Top (Enable/Disable): Disabled by default A good look at the “Extensions Drop-Down Menu” where you can set an app window to be transparent or send it to a specific screen section on your monitor(s). If you open an app it will not automatically lock into a specific section. To lock the window into a specific section drag-and-drop the app window into the desired section. Notice the red outline and highlighted number on “Section 2” below. The red outline and highlighted number serves as an indicator that if you release the app window at that moment it will lock into the outlined/highlighted section. Now that Notepad is locked into “Section 2” you can see that it is maximized within that section. Continue to drag-and-drop your app windows into the appropriate sections as desired…apps can still be reduced to the “Taskbar” the same as before. Options These are the options available for Acer GridVista… Conclusion If you have been wanting the ability to “snap” windows and organize them into specific screen areas then Acer GridVista is definitely a program that you should try out. Links Download Acer GridVista at Softpedia View detailed information at the Acer GridVista Homepage Similar Articles Productive Geek Tips Multitask Like a Pro with AquaSnapHelp Troubleshoot the Blue Screen of Death by Preventing Automatic RebootAdd Windows 7’s AeroSnap Feature to Vista and XPResize Windows to Specific Dimensions Easily With SizerKeyboard Ninja: Assign a Hotkey to any Window TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Playing Games In Chrome Made Easier Stop In The Name Of Love (Firefox addon) Chitika iPad Labs Gives Live iPad Sale Stats Heaven & Hell Finder Icon Using TrueCrypt to Secure Your Data Quickly Schedule Meetings With NeedtoMeet

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Fast Data - Big Data's achilles heel

- by thegreeneman

At OOW 2013 in Mark Hurd and Thomas Kurian's keynote, they discussed Oracle's Fast Data software solution stack and discussed a number of customers deploying Oracle's Big Data / Fast Data solutions and in particular Oracle's NoSQL Database. Since that time, there have been a large number of request seeking clarification on how the Fast Data software stack works together to deliver on the promise of real-time Big Data solutions. Fast Data is a software solution stack that deals with one aspect of Big Data, high velocity. The software in the Fast Data solution stack involves 3 key pieces and their integration: Oracle Event Processing, Oracle Coherence, Oracle NoSQL Database. All three of these technologies address a high throughput, low latency data management requirement. Oracle Event Processing enables continuous query to filter the Big Data fire hose, enable intelligent chained events to real-time service invocation and augments the data stream to provide Big Data enrichment. Extended SQL syntax allows the definition of sliding windows of time to allow SQL statements to look for triggers on events like breach of weighted moving average on a real-time data stream. Oracle Coherence is a distributed, grid caching solution which is used to provide very low latency access to cached data when the data is too big to fit into a single process, so it is spread around in a grid architecture to provide memory latency speed access. It also has some special capabilities to deploy remote behavioral execution for "near data" processing. The Oracle NoSQL Database is designed to ingest simple key-value data at a controlled throughput rate while providing data redundancy in a cluster to facilitate highly concurrent low latency reads. For example, when large sensor networks are generating data that need to be captured while analysts are simultaneously extracting the data using range based queries for upstream analytics. Another example might be storing cookies from user web sessions for ultra low latency user profile management, also leveraging that data using holistic MapReduce operations with your Hadoop cluster to do segmented site analysis. Understand how NoSQL plays a critical role in Big Data capture and enrichment while simultaneously providing a low latency and scalable data management infrastructure thru clustered, always on, parallel processing in a shared nothing architecture. Learn how easily a NoSQL cluster can be deployed to provide essential services in industry specific Fast Data solutions. See these technologies work together in a demonstration highlighting the salient features of these Fast Data enabling technologies in a location based personalization service. The question then becomes how do these things work together to deliver an end to end Fast Data solution. The answer is that while different applications will exhibit unique requirements that may drive the need for one or the other of these technologies, often when it comes to Big Data you may need to use them together. You may have the need for the memory latencies of the Coherence cache, but just have too much data to cache, so you use a combination of Coherence and Oracle NoSQL to handle extreme speed cache overflow and retrieval. Here is a great reference to how these two technologies are integrated and work together. Coherence & Oracle NoSQL Database. On the stream processing side, it is similar as with the Coherence case. As your sliding windows get larger, holding all the data in the stream can become difficult and out of band data may need to be offloaded into persistent storage. OEP needs an extreme speed database like Oracle NoSQL Database to help it continue to perform for the real time loop while dealing with persistent spill in the data stream. Here is a great resource to learn more about how OEP and Oracle NoSQL Database are integrated and work together. OEP & Oracle NoSQL Database.

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Profiling Startup Of VS2012 – dotTrace Profiler

- by Alois Kraus

Jetbrains which is famous for the Resharper tool has also a profiler in its portfolio. I downloaded dotTrace 5.2 Professional (569€+VAT) to check how far I can profile the startup of VS2012. The most interesting startup option is “.NET Process”. With that you can profile the next started .NET process which is very useful if you want to profile an application which is not started by you. I did select Tracing as and Wall time to get similar options across all profilers. For some reason the attach option did not work with .NET 4.5 on my home machine. But I am sure that it did work with .NET 4.0 some time ago. Since we are profiling devenv.exe we can also select “Standalone Application” and start it from the profiler. The startup time of VS does increase about a factor 3 but that is ok. You get mainly three windows to work with. The first one shows the threads where you can drill down thread wise where most time is spent. I The next window is the call tree which does merge all threads together in a similar view. The last and most useful view in my opinion is the Plain List window which is nearly the same as the Method Grid in Ants Profiler. But this time we do get when I enable the Show system functions checkbox not a 150 but 19407 methods to choose from! I really tried with Ants Profiler to find something about out how VS does work but look how much we were missing! When I double click on a method I do get in the lower pane the called methods and their respective timings. This is something really useful and I can nicely drill down to the most important stuff. The measured time seems to be Wall Clock time which is a good thing to see where my time is really spent. You can also use Sampling as profiling method but this does give you much less information. Except for getting a first idea where to look first this profiling mode is not very useful to understand how you system does interact. The options have a good list of presets to hide by default many method and gray them out to concentrate on your code. It does not filter anything out if you enable Show system functions. By default methods from these assemblies are hidden or if the checkbox is checked grayed out. All in all JetBrains has made a nice profiler which does show great detail and it has nice drill down capabilities. The only thing is that I do not trust its measured timings. I did fall several times into the trap with this one to optimize at places which were already fast but the profiler did show high times in these methods. After measuring with Tracing I was certain that the measured times were greatly exaggerated. Especially when IO is involved it seems to have a hard time to subtract its own overhead. What I did miss most was the possibility to profile not only the next started process but to be able to select a process by name and perhaps a count to profile the next n processes of this name. Next: YourKit

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I am trying to figure out the best way to understand how to cache domain objects

- by Brett Ryan

I've always done this wrong, I'm sure a lot of others have too, hold a reference via a map and write through to DB etc.. I need to do this right, and I just don't know how to go about it. I know how I want my objects to be cached but not sure on how to achieve it. What complicates things is that I need to do this for a legacy system where the DB can change without notice to my application. So in the context of a web application, let's say I have a WidgetService which has several methods: Widget getWidget(); Collection<Widget> getAllWidgets(); Collection<Widget> getWidgetsByCategory(String categoryCode); Collection<Widget> getWidgetsByContainer(Integer parentContainer); Collection<Widget> getWidgetsByStatus(String status); Given this, I could decide to cache by method signature, i.e. getWidgetsByCategory("AA") would have a single cache entry, or I could cache widgets individually, which would be difficult I believe; OR, a call to any method would then first cache ALL widgets with a call to getAllWidgets() but getAllWidgets() would produce caches that match all the keys for the other method invocations. For example, take the following untested theoretical code. Collection<Widget> getAllWidgets() { Entity entity = cache.get("ALL_WIDGETS"); Collection<Widget> res; if (entity == null) { res = loadCache(); } else { res = (Collection<Widget>) entity.getValue(); } return res } Collection<Widget> loadCache() { // Get widgets from underlying DB Collection<Widget> res = db.getAllWidgets(); cache.put("ALL_WIDGETS", res); Map<String, List<Widget>> byCat = new HashMap<>(); for (Widget w : res) { // cache by different types of method calls, i.e. by category if (!byCat.containsKey(widget.getCategory()) { byCat.put(widget.getCategory(), new ArrayList<Widget>); } byCat.get(widget.getCatgory(), widget); } cacheCategories(byCat); return res; } Collection<Widget> getWidgetsByCategory(String categoryCode) { CategoryCacheKey key = new CategoryCacheKey(categoryCode); Entity ent = cache.get(key); if (entity == null) { loadCache(); } ent = cache.get(key); return ent == null ? Collections.emptyList() : (Collection<Widget>)ent.getValue(); } NOTE: I have not worked with a cache manager, the above code illustrates cache as some object that may hold caches by key/value pairs, though it's not modelled on any specific implementation. Using this I have the benefit of being able to cache all objects in the different ways they will be called with only single objects on the heap, whereas if I were to cache the method call invocation via say Spring It would (I believe) cache multiple copies of the objects. I really wish to try and understand the best ways to cache domain objects before I go down the wrong path and make it harder for myself later. I have read the documentation on the Ehcache website and found various articles of interest, but nothing to give a good solid technique. Since I'm working with an ERP system, some DB calls are very complicated, not that the DB is slow, but the business representation of the domain objects makes it very clumsy, coupled with the fact that there are actually 11 different DB's where information can be contained that this application is consolidating in a single view, this makes caching quite important.

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XNA Multiplayer Games and Networking

- by JoshReuben

· XNA communication must by default be lightweight – if you are syncing game state between players from the Game.Update method, you must minimize traffic. That game loop may be firing 60 times a second and player 5 needs to know if his tank has collided with any player 3 and the angle of that gun turret. There are no WCF ServiceContract / DataContract niceties here, but at the same time the XNA networking stack simplifies the details. The payload must be simplistic - just an ordered set of numbers that you would map to meaningful enum values upon deserialization. Overview · XNA allows you to create and join multiplayer game sessions, to manage game state across clients, and to interact with the friends list · Dependency on Gamer Services - to receive notifications such as sign-in status changes and game invitations · two types of online multiplayer games: system link game sessions (LAN) and LIVE sessions (WAN). · Minimum dev requirements: 1 Xbox 360 console + Creators Club membership to test network code - run 1 instance of game on Xbox 360, and 1 on a Windows-based computer Network Sessions · A network session is made up of players in a game + up to 8 arbitrary integer properties describing the session · create custom enums – (e.g. GameMode, SkillLevel) as keys in NetworkSessionProperties collection · Player state: lobby, in-play Session Types · local session - for split-screen gaming - requires no network traffic. · system link session - connects multiple gaming machines over a local subnet. · Xbox LIVE multiplayer session - occurs on the Internet. Ranked or unranked Session Updates · NetworkSession class Update method - must be called once per frame. · performs the following actions: o Sends the network packets. o Changes the session state. o Raises the managed events for any significant state changes. o Returns the incoming packet data. · synchronize the session à packet-received and state-change events à no threading issues Session Config · Session host - gaming machine that creates the session. XNA handles host migration · NetworkSession properties: AllowJoinInProgress , AllowHostMigration · NetworkSession groups: AllGamers, LocalGamers, RemoteGamers Subscribe to NetworkSession events · GamerJoined · GamerLeft · GameStarted · GameEnded – use to return to lobby · SessionEnded – use to return to title screen Create a Session session = NetworkSession.Create( NetworkSessionType.SystemLink, maximumLocalPlayers, maximumGamers, privateGamerSlots, sessionProperties ); Start a Session if (session.IsHost) { if (session.IsEveryoneReady) { session.StartGame(); foreach (var gamer in SignedInGamer.SignedInGamers) { gamer.Presence.PresenceMode = GamerPresenceMode.InCombat; Find a Network Session AvailableNetworkSessionCollection availableSessions = NetworkSession.Find( NetworkSessionType.SystemLink, maximumLocalPlayers, networkSessionProperties); availableSessions.AllowJoinInProgress = true; Join a Network Session NetworkSession session = NetworkSession.Join( availableSessions[selectedSessionIndex]); Sending Network Data var packetWriter = new PacketWriter(); foreach (LocalNetworkGamer gamer in session.LocalGamers) { // Get the tank associated with this player. Tank myTank = gamer.Tag as Tank; // Write the data. packetWriter.Write(myTank.Position); packetWriter.Write(myTank.TankRotation); packetWriter.Write(myTank.TurretRotation); packetWriter.Write(myTank.IsFiring); packetWriter.Write(myTank.Health); // Send it to everyone. gamer.SendData(packetWriter, SendDataOptions.None); } Receiving Network Data foreach (LocalNetworkGamer gamer in session.LocalGamers) { // Keep reading while packets are available. while (gamer.IsDataAvailable) { NetworkGamer sender; // Read a single packet. gamer.ReceiveData(packetReader, out sender); if (!sender.IsLocal) { // Get the tank associated with this packet. Tank remoteTank = sender.Tag as Tank; // Read the data and apply it to the tank. remoteTank.Position = packetReader.ReadVector2(); … End a Session if (session.AllGamers.Count == 1) { session.EndGame(); session.Update(); } Performance • Aim to minimize payload, reliable in order messages • Send Data Options: o Unreliable, out of order -(SendDataOptions.None) o Unreliable, in order (SendDataOptions.InOrder) o Reliable, out of order (SendDataOptions.Reliable) o Reliable, in order (SendDataOptions.ReliableInOrder) o Chat data (SendDataOptions.Chat) • Simulate: NetworkSession.SimulatedLatency , NetworkSession.SimulatedPacketLoss • Voice support – NetworkGamer properties: HasVoice ,IsTalking , IsMutedByLocalUser

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Creating a Corporate Data Hub

- by BuckWoody

The Windows Azure Marketplace has a rich assortment of data and software offerings for you to use – a type of Software as a Service (SaaS) for IT workers, not necessarily for end-users. Among those offerings is the “Data Hub” – a codename for a project that ironically actually does what the codename says. In many of our organizations, we have multiple data quality issues. Finding data is one problem, but finding it just once is often a bigger problem. Lots of departments and even individuals have stored the same data more than once, and in some cases, made changes to one of the copies. It’s difficult to know which location or version of the data is authoritative. Then there’s the problem of accessing the data. It’s fairly straightforward to publish a database, share or other location internally to store the data. But then you have to figure out who owns it, how it is controlled, and pass out the various connection strings to those who want to use it. And then you need to figure out how to let folks access the internal data externally – bringing up all kinds of security issues. Finally, in many cases our user community wants us to combine data from the internally sources with external data, bringing up the security, strings, and exploration features up all over again. Enter the Data Hub. This is an online offering, where you assign an administrator and data stewards. You import the data into the service, and it’s available to you - and only you and your organization if you wish. The basic steps for this service are to set up the portal for your company, assign administrators and permissions, and then you assign data areas and import data into them. From there you make them discoverable, and then you have multiple options that you or your users can access that data. You’re then able, if you wish, to combine that data with other data in one location. So how does all that work? What about security? Is it really that easy? And can you really move the data definition off to the Subject Matter Experts (SME’s) that know the particular data stack better than the IT team does? Well, nothing good is easy – but using the Data Hub is actually pretty simple. I’ll give you a link in a moment where you can sign up and try this yourself. Once you sign up, you assign an administrator. From there you’ll create data areas, and then use a simple interface to bring the data in. All of this is done in a portal interface – nothing to install, configure, update or manage. After the data is entered in, and you’ve assigned meta-data to describe it, your users have multiple options to access it. They can simply use the portal – which actually has powerful visualizations you can use on any platform, even mobile phones or tablets. Your users can also hit the data with Excel – which gives them ultimate flexibility for display, all while using an authoritative, single reference for the data. Since the service is online, they can do this wherever they are – given the proper authentication and permissions. You can also hit the service with simple API calls, like this one from C#: http://msdn.microsoft.com/en-us/library/hh921924 You can make HTTP calls instead of code, and the data can even be exposed as an OData Feed. As you can see, there are a lot of options. You can check out the offering here: http://www.microsoft.com/en-us/sqlazurelabs/labs/data-hub.aspx and you can read the documentation here: http://msdn.microsoft.com/en-us/library/hh921938

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eSTEP Newsletter November 2012

- by mseika

Dear Partners,We would like to inform you that the November '12 issue of our Newsletter is now available.The issue contains information to the following topics: News from CorpOracle Celebrates 25 Years of SPARC Innovation; IDC White Papers Finds Growing Customer Comfort with Oracle Solaris Operating System; Oracle Buys Instantis; Pillar Axiom OpenWorld Highlights; Announcement Oracle Solaris 11.1 Availability (data sheet, new features, FAQ's, corporate pages, internal blog, download links, Oracle shop); Announcing StorageTek VSM 6; Announcement Oracle Solaris Cluster 4.1 Availability (new features, FAQ's, cluster corp page, download site, shop for media); Announcement: Oracle Database Appliance 2.4 patch update becomes available Technical SectionOracle White papers on SPARC SuperCluster; Understanding Parallel Execution; With LTFS, Tape is Gaining Storage Ground with additional link to How to Create Oracle Solaris 11 Zones with Oracle Enterprise Manager Ops Center; Provisioning Capabilities of Oracle Enterprise Ops Center Manager 12c; Maximizing your SPARC T4 Oracle Solaris Application Performance with the following articles: SPARC T4 Servers Set World Record on Siebel CRM 8.1.1.4 Benchmark, SPARC T4-Based Highly Scalable Solutions Posts New World Record on SPECjEnterprise2010 Benchmark, SPARC T4 Server Delivers Outstanding Performance on Oracle Business Intelligence Enterprise Edition 11g; Oracle SUN ZFS Storage Appliance Reference Architecture for VMware vSphere4; Why 4K? - George Wilson's ZFS Day Talk; Pillar Axiom 600 with connected subjects: Oracle Introduces Pillar Axiom Release 5 Storage System Software, Driving down the high cost of Storage, This Provisioning with Pilar Axiom 600, Pillar Axiom 600- System overview and architecture; Migrate to Oracle;s SPARC Systems; Top 5 Reasons to Migrate to Oracle's SPARC Systems Learning & EventsRecently delivered Techcasts: Learning Paths; Oracle Database 11g: Database Administration (New) - Learning Path; Webcast: Drill Down on Disaster Recovery; What are Oracle Users Doing to Improve Availability and Disaster Recovery; SAP NetWeaver and Oracle Exadata Database Machine ReferencesARTstor Selects Oracle’s Sun ZFS Storage 7420 Appliances To Support Rapidly Growing Digital Image Library, Scottish Widows Cuts Sales Administration 20%, Reduces Time to Prepare Reports by 75%, and Achieves Return on Investment in First Year, Oracle's CRM Cloud Service Powers Innovation: Applications on Demand; Technology on Demand, How toHow to Migrate Your Data to Oracle Solaris 11 Using Shadow Migration; Using svcbundle to Create SMF Manifests and Profiles in Oracle Solaris 11; How to prepare a Sun ZFS Storage Appliance to Serve as a Storage Devise with Oracle Enterprise Manager Ops Center 12c; Command Summary: Basic Operations with the Image Packaging System In Oracle Solaris 11; How to Update to Oracle Solaris 11.1 Using the Image Packaging System, How to Migrate Oracle Database from Oracle Solaris 8 to Oracle Solaris 11; Setting Up, Configuring, and Using an Oracle WebLogic Server Cluster; Ease the Chaos with Automated Patching: Oracle Enterprise Manager Cloud Control 12c; Book excerpt: Oracle Exalogic Elastic Cloud HandbookYou find the Newsletter on our portal under eSTEP News ---> Latest Newsletter. You will need to provide your email address and the pin below to get access. Link to the portal is shown below.URL: http://launch.oracle.com/PIN: eSTEP_2011Previous published Newsletters can be found under the Archived Newsletters section and more useful information under the Events, Download and Links tab. Feel free to explore and any feedback is appreciated to help us improve the service and information we deliver.Thanks and best regards,Partner HW Enablement EMEA

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It’s official – Red Gate is a great place to work!

- by red@work

At a glittering award ceremony last week, we found out that we’re officially the 14th best small company to work for in the whole of the UK! This is no mean feat, considering that about 1,000 companies enter the Sunday Times Top 100 best companies awards each year. Most of these are in the small companies category too. It's the fourth year in a row for us to be in the Top 100 list and we're tickled pink because the results are based on employee opinion. We’re particularly proud to be the best small company in Cambridge (in the whole of East Anglia, in fact) and the best small software development company in the entire UK. So how does it all work? Well, 90% of us took the time to answer over 70 questions on categories such as management, benefits, wellbeing, leadership, giving something back and what we think of Red Gate as a whole. It makes you think about every part of day to day working life and how you feel about it. Do you slightly or strongly agree or disagree that your manager motivates your to do your best every day, or that you have confidence in Red Gate's leaders, or that you’re not spending too much time working? It's great to see that we had one of the best scores in the country for the question "Do you think your company takes advantage of you?" We got particularly high scores for management, wellbeing and for giving something back too. A few of us got dressed up and headed to London for the awards; very excited about where we’d place but slightly nervous about having to get up on stage. There was a last minute hic up with a bow tie but the Managing Editor of the Sunday Times kindly stepped in to offer his assistance just before we had our official photo taken. We were nominated for two Special Recognition Awards. Despite not bringing them home this year, we're very proud to be nominated as there are only three nominations in each category. First we were up for the Training and Development award. Best Companies loved that we get together at lunchtimes to teach each other photography, cookery and French, as well as our book clubs and techie talks. And of course they liked our opportunities to go on training courses and to jet off to international conferences. Our other nomination was for the Wellbeing award. Best Companies loved our free food (and let’s face it, so do we). Porridge or bacon sandwiches for breakfast, a three course hot dinner, and free fruit and cereals all day long. If all that has an affect on the waistline then there are plenty of sporty activities for us all to get involved in, such as yoga, running or squash. Or if that’s not your thing then a relaxing massage helps us all to unwind every few months or so. The awards were hosted by news presenter Kate Silverton. She gave us a special mention during the ceremony for having great customer engagement as well as employee engagement, after we told her about Rodney Landrum (a Friend of Red Gate) tattooing our logo on his arm. We showed off our customised dinner jacket (thanks to Dom from Usability) with a flashing Red Gate logo on the back and she seemed suitability impressed. Back in the office the next day, we popped open the champagne and raised a glass to our success. Neil, our joint CEO, talked about how pleased he was with the award because it's based on the opinions of the people that count – us. You can read more about the Sunday Times awards here. By the way, we're still growing and are still hiring. If you’d like to keep up with our latest vacancies then why not follow us on Twitter at twitter.com/redgatecareers. Right now we're busy hiring in development, test, sales, product management, web development, and project management. Here's a link to our current job opportunities page – we'd love to hear from great people who are looking for a great place to work! After all, we're only great because of the people who work here. Post by: Alice Chapman

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The inevitable Hello World post!

- by brendonpage

Greetings to anyone reading this! This is my first of hopefully many posts. I would like to use this post to introduce myself and to let you know what to expect from this blog in future. Okay so a bit about myself. In case you missed the name of this blog, my name is Brendon Page! I am a Software Developer from South Africa and work for a small company who’s main focus is producing software for the kitchen cupboard industry, although from time to time we do produce custom solutions for other industries. I work in a small team of 3, including myself, and am fortunate enough to work from home! I have been involved in IT since 1996, which is when I got my first PC, and started working as a junior programmer in 2003. Outside of work I enjoy playing squash, PC Games and of course LANing with my friends. If I get any free time between all of that I will usually dedicate some of it to a personal project, these are mainly prototypes for an idea I have had or for something that could be useful at work. I was in 2 minds on whether to include a photo of myself. The reason for this was because while I was looking for a suitable photo to use, it dawned on me how much time I dedicate to pulling funny faces in photos! I also realized how little I shave, which I blame completely on working form home. So after much debate here I am, funny face, beard and all! Now that you know a bit about me lets move onto what expect from this blog. I work predominantly with Microsoft technologies so most if not all of my posts will be related to something Microsoft. Since most of my job entails Software Development you can expect a lot of posts which will deal with the .NET Framework. I am currently working on a large Silverlight project, so my first few posts will be targeted at in that direction. I will be striving to make the content of my posts as useful as possible from both an explanation and code perspective, I aim to include a working solution for every post, which I will put up on my skydrive for download. Here is what I have planned for my next few posts: Where did my session variables go? Here I will take you through the lessons I learnt the hard way about the ASP.NET session. I am not going to go into to much depth in this post, as there is already a lot of information available on it. I mainly want to cover it in an effort to keep the scope creep of my posts to a minimum, some the solutions I upload will use it and I would like to have a post that I can reference to explain why I am doing something a certain way. Uploading files through SIlverlight Again there is a lot of existing information on this topic, so I wont be going into to much depth, but I will be using the solution from this as a base for my next post. Generating and Displaying DeepZoom images dynamically in Silverlight Well the title pretty much speaks for it’s self on this one. As I mentioned I will be building off the solution that I create in my ‘Uploading files through Silverlight’ post. Securing DeepZoom images using a custom implementation of the MultiScaleTileSource In this post I will look at the privacy issue surrounding the default usage of DeepZoom images in Silverlight and how to overcome it. This makes the use of DeepZoom in privacy conscious applications more viable. Thanks to anyone who actually read this post! I look forward to producing more which will hopefully be helpful to you.

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Investigating on xVelocity (VertiPaq) column size

- by Marco Russo (SQLBI)

In January I published an article about how to optimize high cardinality columns in VertiPaq. In the meantime, VertiPaq has been rebranded to xVelocity: the official name is now “xVelocity in-memory analytics engine (VertiPaq)” but using xVelocity and VertiPaq when we talk about Analysis Services has the same meaning. In this post I’ll show how to investigate on columns size of an existing Tabular database so that you can find the most important columns to be optimized. A first approach can be looking in the DataDir of Analysis Services and look for the folder containing the database. Then, look for the biggest files in all subfolders and you will find the name of a file that contains the name of the most expensive column. However, this heuristic process is not very optimized. A better approach is using a DMV that provides the exact information. For example, by using the following query (open SSMS, open an MDX query on the database you are interested to and execute it) you will see all database objects sorted by used size in a descending way. SELECT * FROM $SYSTEM.DISCOVER_STORAGE_TABLE_COLUMN_SEGMENTS ORDER BY used_size DESC You can look at the first rows in order to understand what are the most expensive columns in your tabular model. The interesting data provided are: TABLE_ID: it is the name of the object – it can be also a dictionary or an index COLUMN_ID: it is the column name the object belongs to – you can also see ID_TO_POS and POS_TO_ID in case they refer to internal indexes RECORDS_COUNT: it is the number of rows in the column USED_SIZE: it is the used memory for the object By looking at the ration between USED_SIZE and RECORDS_COUNT you can understand what you can do in order to optimize your tabular model. Your options are: Remove the column. Yes, if it contains data you will never use in a query, simply remove the column from the tabular model Change granularity. If you are tracking time and you included milliseconds but seconds would be enough, round the data source column to the nearest second. If you have a floating point number but two decimals are good enough (i.e. the temperature), round the number to the nearest decimal is relevant to you. Split the column. Create two or more columns that have to be combined together in order to produce the original value. This technique is described in VertiPaq optimization article. Sort the table by that column. When you read the data source, you might consider sorting data by this column, so that the compression will be more efficient. However, this technique works better on columns that don’t have too many distinct values and you will probably move the problem to another column. Sorting data starting from the lower density columns (those with a few number of distinct values) and going to higher density columns (those with high cardinality) is the technique that provides the best compression ratio. After the optimization you should be able to reduce the used size and improve the count/size ration you measured before. If you are interested in a longer discussion about internal storage in VertiPaq and you want understand why this approach can save you space (and time), you can attend my 24 Hours of PASS session “VertiPaq Under the Hood” on March 21 at 08:00 GMT.

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The battle between Java vs. C#

The battle between Java vs. C# has been a big debate amongst the development community over the last few years. Both languages have specific pros and cons based on the needs of a particular project. In general both languages utilize a similar coding syntax that is based on C++, and offer developers similar functionality. This being said, the communities supporting each of these languages are very different. The divide amongst the communities is much like the political divide in America, where the Java community would represent the Democrats and the .Net community would represent the Republicans. The Democratic Party is a proponent of the working class and the general population. Currently, Java is deeply entrenched in the open source community that is distributed freely to anyone who has an interest in using it. Open source communities rely on developers to keep it alive by constantly contributing code to make applications better; essentially they develop code by the community. This is in stark contrast to the C# community that is typically a pay to play community meaning that you must pay for code that you want to use because it is developed as products to be marketed and sold for a profit. This ties back into my reference to the Republicans because they typically represent the needs of business and personal responsibility. This is emphasized by the belief that code is a commodity and that it can be sold for a profit which is in direct conflict to the laissez-faire beliefs of the open source community. Beyond the general differences between Java and C#, they also target two different environments. Java is developed to be environment independent and only requires that users have a Java virtual machine running in order for the java code to execute. C# on the other hand typically targets any system running a windows operating system and has the appropriate version of the .Net Framework installed. However, recently there has been push by a segment of the Open source community based around the Mono project that lets C# code run on other non-windows operating systems. In addition, another feature of C# is that it compiles into an intermediate language, and this is what is executed when the program runs. Because C# is reduced down to an intermediate language called Common Language Runtime (CLR) it can be combined with other languages that are also compiled in to the CLR like Visual Basic (VB) .Net, and F#. The allowance and interaction between multiple languages in the .Net Framework enables projects to utilize existing code bases regardless of the actual syntax because they can be compiled in to CLR and executed as one codebase. As a software engineer I personally feel that it is really important to learn as many languages as you can or at least be open to learn as many languages as you can because no one language will work in every situation. In some cases Java may be a better choice for a project and others may be C#. It really depends on the requirements of a project and the time constraints. In addition, I feel that is really important to concentrate on understanding the logic of programming and be able to translate business requirements into technical requirements. If you can understand both programming logic and business requirements then deciding which language to use is just basically choosing what syntax to write for a given business problem or need. In regards to code refactoring and dynamic languages it really does not matter. Eventually all projects will be refactored or decommissioned to allow for progress. This is the way of life in the software development industry. The language of a project should not be chosen based on the fact that a project will eventually be refactored because they all will get refactored.

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Subterranean IL: Exception handling 2

- by Simon Cooper

Control flow in and around exception handlers is tightly controlled, due to the various ways the handler blocks can be executed. To start off with, I'll describe what SEH does when an exception is thrown. Handling exceptions When an exception is thrown, the CLR stops program execution at the throw statement and searches up the call stack looking for an appropriate handler; catch clauses are analyzed, and filter blocks are executed (I'll be looking at filter blocks in a later post). Then, when an appropriate catch or filter handler is found, the stack is unwound to that handler, executing successive finally and fault handlers in their own stack contexts along the way, and program execution continues at the start of the catch handler. Because catch, fault, finally and filter blocks can be executed essentially out of the blue by the SEH mechanism, without any reference to preceding instructions, you can't use arbitary branches in and out of exception handler blocks. Instead, you need to use specific instructions for control flow out of handler blocks: leave, endfinally/endfault, and endfilter. Exception handler control flow try blocks You cannot branch into or out of a try block or its handler using normal control flow instructions. The only way of entering a try block is by either falling through from preceding instructions, or by branching to the first instruction in the block. Once you are inside a try block, you can only leave it by throwing an exception or using the leave <label> instruction to jump to somewhere outside the block and its handler. The leave instructions signals the CLR to execute any finally handlers around the block. Most importantly, you cannot fall out of the block, and you cannot use a ret to return from the containing method (unlike in C#); you have to use leave to branch to a ret elsewhere in the method. As a side effect, leave empties the stack. catch blocks The only way of entering a catch block is if it is run by the SEH. At the start of the block execution, the thrown exception will be the only thing on the stack. The only way of leaving a catch block is to use throw, rethrow, or leave, in a similar way to try blocks. However, one thing you can do is use a leave to branch back to an arbitary place in the handler's try block! In other words, you can do this: .try { // ... newobj instance void [mscorlib]System.Exception::.ctor() throw MidTry: // ... leave.s RestOfMethod } catch [mscorlib]System.Exception { // ... leave.s MidTry } RestOfMethod: // ... As far as I know, this mechanism is not exposed in C# or VB. finally/fault blocks The only way of entering a finally or fault block is via the SEH, either as the result of a leave instruction in the corresponding try block, or as part of handling an exception. The only way to leave a finally or fault block is to use endfinally or endfault (both compile to the same binary representation), which continues execution after the finally/fault block, or, if the block was executed as part of handling an exception, signals that the SEH can continue walking the stack. filter blocks I'll be covering filters in a separate blog posts. They're quite different to the others, and have their own special semantics. Phew! Complicated stuff, but it's important to know if you're writing or outputting exception handlers in IL. Dealing with the C# compiler is probably best saved for the next post.

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django/python: is one view that handles two sibling models a good idea?

- by clime

I am using django multi-table inheritance: Video and Image are models derived from Media. I have implemented two views: video_list and image_list, which are just proxies to media_list. media_list returns images or videos (based on input parameter model) for a certain object, which can be of type Event, Member, or Crag. The view alters its behaviour based on input parameter action (better name would be mode), which can be of value "edit" or "view". The problem is that I need to ask whether the input parameter model contains Video or Image in media_list so that I can do the right thing. Similar condition is also in helper method media_edit_list that is called from the view. I don't particularly like it but the only alternative I can think of is to have separate (but almost the same) logic for video_list and image_list and then probably also separate helper methods for videos and images: video_edit_list, image_edit_list, video_view_list, image_view_list. So four functions instead of just two. That I like even less because the video functions would be very similar to the respective image functions. What do you recommend? Here is extract of relevant parts: http://pastebin.com/07t4bdza. I'll also paste the code here: #urls url(r'^media/images/(?P<rel_model_tag>(event|member|crag))/(?P<rel_object_id>\d+)/(?P<action>(view|edit))/$', views.image_list, name='image-list') url(r'^media/videos/(?P<rel_model_tag>(event|member|crag))/(?P<rel_object_id>\d+)/(?P<action>(view|edit))/$', views.video_list, name='video-list') #views def image_list(request, rel_model_tag, rel_object_id, mode): return media_list(request, Image, rel_model_tag, rel_object_id, mode) def video_list(request, rel_model_tag, rel_object_id, mode): return media_list(request, Video, rel_model_tag, rel_object_id, mode) def media_list(request, model, rel_model_tag, rel_object_id, mode): rel_model = tag_to_model(rel_model_tag) rel_object = get_object_or_404(rel_model, pk=rel_object_id) if model == Image: star_media = rel_object.star_image else: star_media = rel_object.star_video filter_params = {} if rel_model == Event: filter_params['event'] = rel_object_id elif rel_model == Member: filter_params['members'] = rel_object_id elif rel_model == Crag: filter_params['crag'] = rel_object_id media_list = model.objects.filter(~Q(id=star_media.id)).filter(**filter_params).order_by('date_added').all() context = { 'media_list': media_list, 'star_media': star_media, } if mode == 'edit': return media_edit_list(request, model, rel_model_tag, rel_object_id, context) return media_view_list(request, model, rel_model_tag, rel_object_id, context) def media_view_list(request, model, rel_model_tag, rel_object_id, context): if request.is_ajax(): context['base_template'] = 'boxes/base-lite.html' return render(request, 'media/list-items.html', context) def media_edit_list(request, model, rel_model_tag, rel_object_id, context): if model == Image: get_media_edit_record = get_image_edit_record else: get_media_edit_record = get_video_edit_record media_list = [get_media_edit_record(media, rel_model_tag, rel_object_id) for media in context['media_list']] if context['star_media']: star_media = get_media_edit_record(context['star_media'], rel_model_tag, rel_object_id) else: star_media = None json = simplejson.dumps({ 'star_media': star_media, 'media_list': media_list, }) return HttpResponse(json, content_type=json_response_mimetype(request)) def get_image_edit_record(image, rel_model_tag, rel_object_id): record = { 'url': image.image.url, 'name': image.title or image.filename, 'type': mimetypes.guess_type(image.image.path)[0] or 'image/png', 'thumbnailUrl': image.thumbnail_2.url, 'size': image.image.size, 'id': image.id, 'media_id': image.media_ptr.id, 'starUrl':reverse('image-star', kwargs={'image_id': image.id, 'rel_model_tag': rel_model_tag, 'rel_object_id': rel_object_id}), } return record def get_video_edit_record(video, rel_model_tag, rel_object_id): record = { 'url': video.embed_url, 'name': video.title or video.url, 'type': None, 'thumbnailUrl': video.thumbnail_2.url, 'size': None, 'id': video.id, 'media_id': video.media_ptr.id, 'starUrl': reverse('video-star', kwargs={'video_id': video.id, 'rel_model_tag': rel_model_tag, 'rel_object_id': rel_object_id}), } return record # models class Media(models.Model, WebModel): title = models.CharField('title', max_length=128, default='', db_index=True, blank=True) event = models.ForeignKey(Event, null=True, default=None, blank=True) crag = models.ForeignKey(Crag, null=True, default=None, blank=True) members = models.ManyToManyField(Member, blank=True) added_by = models.ForeignKey(Member, related_name='added_images') date_added = models.DateTimeField('date added', auto_now_add=True, null=True, default=None, editable=False) class Image(Media): image = ProcessedImageField(upload_to='uploads', processors=[ResizeToFit(width=1024, height=1024, upscale=False)], format='JPEG', options={'quality': 75}) thumbnail_1 = ImageSpecField(source='image', processors=[SmartResize(width=178, height=134)], format='JPEG', options={'quality': 75}) thumbnail_2 = ImageSpecField(source='image', #processors=[SmartResize(width=256, height=192)], processors=[ResizeToFit(height=164)], format='JPEG', options={'quality': 75}) class Video(Media): url = models.URLField('url', max_length=256, default='') embed_url = models.URLField('embed url', max_length=256, default='', blank=True) author = models.CharField('author', max_length=64, default='', blank=True) thumbnail = ProcessedImageField(upload_to='uploads', processors=[ResizeToFit(width=1024, height=1024, upscale=False)], format='JPEG', options={'quality': 75}, null=True, default=None, blank=True) thumbnail_1 = ImageSpecField(source='thumbnail', processors=[SmartResize(width=178, height=134)], format='JPEG', options={'quality': 75}) thumbnail_2 = ImageSpecField(source='thumbnail', #processors=[SmartResize(width=256, height=192)], processors=[ResizeToFit(height=164)], format='JPEG', options={'quality': 75}) class Crag(models.Model, WebModel): name = models.CharField('name', max_length=64, default='', db_index=True) normalized_name = models.CharField('normalized name', max_length=64, default='', editable=False) type = models.IntegerField('crag type', null=True, default=None, choices=crag_types) description = models.TextField('description', default='', blank=True) country = models.ForeignKey('country', null=True, default=None) #TODO: make this not null when db enables it latitude = models.FloatField('latitude', null=True, default=None) longitude = models.FloatField('longitude', null=True, default=None) location_index = FixedCharField('location index', length=24, default='', editable=False, db_index=True) # handled by db, used for marker clustering added_by = models.ForeignKey('member', null=True, default=None) #route_count = models.IntegerField('route count', null=True, default=None, editable=False) date_created = models.DateTimeField('date created', auto_now_add=True, null=True, default=None, editable=False) last_modified = models.DateTimeField('last modified', auto_now=True, null=True, default=None, editable=False) star_image = models.ForeignKey('Image', null=True, default=None, related_name='star_crags', on_delete=models.SET_NULL) star_video = models.ForeignKey('Video', null=True, default=None, related_name='star_crags', on_delete=models.SET_NULL)

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Test Fest Pop Quiz!

- by Kristin Rose

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size: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;} Question: Where can partners go during OPN Exchange to take complementary certification testing, and upon completing it, receive the credentials of a Certified Specialist, while having it count towards their company’s Specialization and upgrade within the OPN program? Answer: A.) Test Fest B.) Test Fest C.) All of the Above You are right! Test Fest is back by popular demand, and has been included as one of the many partner benefits for attending OPN Exchange this year. Join us from October 1-4th in the Marriott Marquis, Juniper Room at Oracle OpenWorld and get recognized! For times and registration, visit the Oracle OpenWorld Test Fest page and be sure to “study up” by watching this short video on Test Fest at Oracle OpenWorld 2012 below! Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size: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;} With over 100 exam titles and four days of sessions, you’re sure to walk away with an A+! Best of Luck, The OPN Communications Team

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Profiling Startup Of VS2012 – JustTrace Profiler

- by Alois Kraus

JustTrace is made by Telerik which is mainly known for its collection of UI controls. The current version (2012.3.1127.0) does include a performance and memory profiler which does cost 614€ and is currently with a special offer for 306€ on sale. It does include one year of free upgrades. The uneven € numbers are calculated from the 799€ and 50% dicsount price. The UI is already in Metro style and simple to use. Multi process, attach, method recording filter are not supported. It looks like JustTrace is like Ants a Just My Code profiler. For stuff where you do not have the pdbs or you want to dig deeper into the BCL code you will not get far. After getting the profile data you get in the All Methods grid a plain list with hit count and own time. The method list for all methods is also suspiciously short which is a clear sign that you will not get far during the analysis of foreign code. But at least there is also a memory profiler included. For this I have to choose in the first window for Profiling Type “Memory Profiler” to check the memory consumption of VS. There are some interesting number to see but I do really miss from YourKit the thread stack window. How am I supposed to get a clue when much memory is allocated and the CPU consumption is high in which places I should look? The Snapshot summary gives a rough overview which is ok for a first impression. Next is Assemblies? This gives you a list of all loaded assemblies. Not terribly useful. The By Type view gives you exactly what it is supposed to do. You have to keep in mind that this list is filtered by the types you did check in the Assemblies list. The By Type instance list does only show types from assemblies which do not originate from Microsoft. By default mscorlib and System are not checked. That is the reason why for the first time my By Type window looked like The idea behind this feature is to show only your instances because you are ultimately responsible for the overall memory consumption. I am not sure if I do like this feature because by default it does hide too much. I do want to see at least how many strings and arrays are allocated. A simple namespace filter would also do it in my opinion. Now you can examine all string instances and look who in the object graph does keep a reference on them. That is nice but YourKit has the big plus that you can also look into the string contents. I am also not sure how in the graph cycles are visualized and what will happen if you have thousands of objects referencing you. That's pretty much it about JustTrace. It can help the average developer to pinpoint performance and memory issues by just looking at his own code and instances. Showing them more will not help them because the sheer amount of information will overwhelm them. And you need to have a pretty good understanding how the GC and the CLR does work. When you have a performance issue at a customer machine it is sometimes very helpful to be able a bring a profiler onto the machine (no pdbs, …) and to get a full snapshot of all processes which are in the problematic use case involved. For these more advanced use cased JustTrace is certainly the wrong tool. Next: SpeedTrace

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Patterns for a tree of persistent data with multiple storage options?

- by Robin Winslow

I have a real-world problem which I'll try to abstract into an illustrative example. So imagine I have data objects in a tree, where parent objects can access children, and children can access parents: // Interfaces interface IParent<TChild> { List<TChild> Children; } interface IChild<TParent> { TParent Parent; } // Classes class Top : IParent<Middle> {} class Middle : IParent<Bottom>, IChild<Top> {} class Bottom : IChild<Middle> {} // Usage var top = new Top(); var middles = top.Children; // List<Middle> foreach (var middle in middles) { var bottoms = middle.Children; // List<Bottom> foreach (var bottom in bottoms) { var middle = bottom.Parent; // Access the parent var top = middle.Parent; // Access the grandparent } } All three data objects have properties that are persisted in two data stores (e.g. a database and a web service), and they need to reflect and synchronise with the stores. Some objects only request from the web service, some only write to it. Data Mapper My favourite pattern for data access is Data Mapper, because it completely separates the data objects themselves from the communication with the data store: class TopMapper { public Top FetchById(int id) { var top = new Top(DataStore.TopDataById(id)); top.Children = MiddleMapper.FetchForTop(Top); return Top; } } class MiddleMapper { public Middle FetchById(int id) { var middle = new Middle(DataStore.MiddleDataById(id)); middle.Parent = TopMapper.FetchForMiddle(middle); middle.Children = BottomMapper.FetchForMiddle(bottom); return middle; } } This way I can have one mapper per data store, and build the object from the mapper I want, and then save it back using the mapper I want. There is a circular reference here, but I guess that's not a problem because most languages can just store memory references to the objects, so there won't actually be infinite data. The problem with this is that every time I want to construct a new Top, Middle or Bottom, it needs to build the entire object tree within that object's Parent or Children property, with all the data store requests and memory usage that that entails. And in real life my tree is much bigger than the one represented here, so that's a problem. Requests in the object In this the objects request their Parents and Children themselves: class Middle { private List<Bottom> _children = null; // cache public List<Bottom> Children { get { _children = _children ?? BottomMapper.FetchForMiddle(this); return _children; } set { BottomMapper.UpdateForMiddle(this, value); _children = value; } } } I think this is an example of the repository pattern. Is that correct? This solution seems neat - the data only gets requested from the data store when you need it, and thereafter it's stored in the object if you want to request it again, avoiding a further request. However, I have two different data sources. There's a database, but there's also a web service, and I need to be able to create an object from the web service and save it back to the database and then request it again from the database and update the web service. This also makes me uneasy because the data objects themselves are no longer ignorant of the data source. We've introduced a new dependency, not to mention a circular dependency, making it harder to test. And the objects now mask their communication with the database. Other solutions Are there any other solutions which could take care of the multiple stores problem but also mean that I don't need to build / request all the data every time?

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Investigating on xVelocity (VertiPaq) column size

- by Marco Russo (SQLBI)

In January I published an article about how to optimize high cardinality columns in VertiPaq. In the meantime, VertiPaq has been rebranded to xVelocity: the official name is now “xVelocity in-memory analytics engine (VertiPaq)” but using xVelocity and VertiPaq when we talk about Analysis Services has the same meaning. In this post I’ll show how to investigate on columns size of an existing Tabular database so that you can find the most important columns to be optimized. A first approach can be looking in the DataDir of Analysis Services and look for the folder containing the database. Then, look for the biggest files in all subfolders and you will find the name of a file that contains the name of the most expensive column. However, this heuristic process is not very optimized. A better approach is using a DMV that provides the exact information. For example, by using the following query (open SSMS, open an MDX query on the database you are interested to and execute it) you will see all database objects sorted by used size in a descending way. SELECT * FROM $SYSTEM.DISCOVER_STORAGE_TABLE_COLUMN_SEGMENTS ORDER BY used_size DESC You can look at the first rows in order to understand what are the most expensive columns in your tabular model. The interesting data provided are: TABLE_ID: it is the name of the object – it can be also a dictionary or an index COLUMN_ID: it is the column name the object belongs to – you can also see ID_TO_POS and POS_TO_ID in case they refer to internal indexes RECORDS_COUNT: it is the number of rows in the column USED_SIZE: it is the used memory for the object By looking at the ration between USED_SIZE and RECORDS_COUNT you can understand what you can do in order to optimize your tabular model. Your options are: Remove the column. Yes, if it contains data you will never use in a query, simply remove the column from the tabular model Change granularity. If you are tracking time and you included milliseconds but seconds would be enough, round the data source column to the nearest second. If you have a floating point number but two decimals are good enough (i.e. the temperature), round the number to the nearest decimal is relevant to you. Split the column. Create two or more columns that have to be combined together in order to produce the original value. This technique is described in VertiPaq optimization article. Sort the table by that column. When you read the data source, you might consider sorting data by this column, so that the compression will be more efficient. However, this technique works better on columns that don’t have too many distinct values and you will probably move the problem to another column. Sorting data starting from the lower density columns (those with a few number of distinct values) and going to higher density columns (those with high cardinality) is the technique that provides the best compression ratio. After the optimization you should be able to reduce the used size and improve the count/size ration you measured before. If you are interested in a longer discussion about internal storage in VertiPaq and you want understand why this approach can save you space (and time), you can attend my 24 Hours of PASS session “VertiPaq Under the Hood” on March 21 at 08:00 GMT.

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Class design issue

- by user2865206

I'm new to OOP and a lot of times I become stumped in situations similar to this example: Task: Generate an XML document that contains information about a person. Assume the information is readily available in a database. Here is an example of the structure: <Person> <Name>John Doe</Name> <Age>21</Age> <Address> <Street>100 Main St.</Street> <City>Sylvania</City> <State>OH</State> </Address> <Relatives> <Parents> <Mother> <Name>Jane Doe</Name> </Mother> <Father> <Name>John Doe Sr.</Name> </Father> </Parents> <Siblings> <Brother> <Name>Jeff Doe</Name> </Brother> <Brother> <Name>Steven Doe</Name> </Brother> </Siblings> </Relatives> </Person> Ok lets create a class for each tag (ie: Person, Name, Age, Address) Lets assume each class is only responsible for itself and the elements directly contained Each class will know (have defined by default) the classes that are directly contained within them Each class will have a process() function that will add itself and its childeren to the XML document we are creating When a child is drawn, as in the previous line, we will have them call process() as well Now we are in a recursive loop where each object draws their childeren until all are drawn But what if only some of the tags need to be drawn, and the rest are optional? Some are optional based on if the data exists (if we have it, we must draw it), and some are optional based on the preferences of the user generating the document How do we make sure each object has the data it needs to draw itself and it's childeren? We can pass down a massive array through every object, but that seems shitty doesnt it? We could have each object query the database for it, but thats a lot of queries, and how does it know what it's query is? What if we want to get rid of a tag later? There is no way to reference them. I've been thinking about this for 20 hours now. I feel like I am misunderstanding a design principle or am just approaching this all wrong. How would you go about programming something like this? I suppose this problem could apply to any senario where there are classes that create other classes, but the classes created need information to run. How do I get the information to them in a way that doesn't seem fucky? Thanks for all of your time, this has been kicking my ass.

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MVC Communication Pattern

- by Kedu

This is kind of a follow up question to this http://stackoverflow.com/questions/23743285/model-view-controller-and-callbacks, but I wanted to post it separately, because its kind of a different topic. I'm working on a multiplayer cardgame for the Android platform. I split the project into MVC which fits the needs pretty good, but I'm currently stuck because I can't figure out a good way to communicate between the different parts. I have everything setup and working with the controller being a big state machine, which is called over and over from the gameloop, and calls getter methods from the GUI and the android/network part to get the input. The input itself in the GUI and network is set by inputlisteners that set a local variable which I read in the getter method. So far so good, this is working. But my problem is, the controller has to check every input separately,so if I want to add an input I have to check in which states its valid and call the getter method from all these states. This is not good, and lets the code look pretty ugly, makes additions uncomfortable and adds redundance. So what I've got from the question I mentioned above is that some kind of command or event pattern will fit my needs. What I want to do is to create a shared and threadsafe queue in the controller and instead of calling all these getter methods, I just check the queue for new input and proceed it. On the other side, the GUI and network don't have all these getters, but instead create an event or command and send it to the controller through, for example, observer/observable. Now my problem: I can't figure out a way, for these commands/events to fit a common interface (which the queue can store) and still transport different kind of data (button clicks, cards that are played, the player id the command comes from, synchronization data etc.). If I design the communication as command pattern, I have to stick all the information that is needed to execute the command into it when its created, that's impossible because the GUI or network has no knowledge of all the things the controller needs to execute stuff that needs to be done when for example a card is played. I thought about getting this stuff into the command when executing it. But over all the different commands I have, I would need all the information the controller has, and thus give the command a reference to the controller which would make everything in it public, which is real bad design I guess. So, I could try some kind of event pattern. I have to transport data in the event. So, like the command, I would have an interface, which all events have in common, and can be stored in the shared queue. I could create a big enum with all the different events that a are possible, save one of these enums in the actual event, and build a big switch case for the events, to proceed different stuff for different events. The problem here: I have different data for all the events. But I need a common interface, to store the events in a queue. How do I get the specific data, if I can only access the event through the interface? Even if that wouldn't be a problem, I'm creating another big switch case, which looks ugly, and when i want to add a new event, I have to create the event itself, the case, the enum, and the method that's called with the data. I could of course check the event with the enum and cast it to its type, so I can call event type specific methods that give me the data I need, but that looks like bad design too.

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Microsoft Certifications – how to prep? and why?

- by Kelly Jones

I often get asked by my colleagues, “how do you prepare for Microsoft exams?” Well, the answer for me is a little complicated, so I thought I’d write up here what I do. The first thing I do is go to Microsoft’s website to find the exam that I need to take. If you’re looking to get a particular certification, then their site lists the exam or exams that you’ll need to pass. If you’ve already taken an exam, you can log onto the MCP website and use their certification planner. This little tool tells you what tests you need, based on the exams you’ve already passed. It is very helpful with the certifications that are multiple tests and especially ones that have electives. Once you’ve identified the test, you can use Microsoft’s website to see the topics that it covers. This is a good outline to follow when you study. I’ll keep this handy to reference back throughout my studying to make sure that I’m covering all the topics I need to know. The next step is probably where I am a little different from others. IF the exam outline covers material that I’ve already been working with, then I’ll skip a lot of the studying and go directly to the practice tests. However, if I’m looking at the outline and wondering how in the world do you do that? – then it’s time to hit the books. So, where to find study materials? Try typing in the exam number into any search engine. You’ll typically find a ton of resources. If you’re lucky, you’ll find books that others recommend based on their studying and exam experience. As a Sogeti employee, I have access to three really good resources: an internal company list of all of the consultants who have passed particular tests (on our Connex website), Books 24x7, and Transcender practice exams. Once my studying is done (either through books or experience), I’ll go through the practice exams. I find them really helpful in getting my knowledge lined up to the thinking process that the exam writers use. If I’m relying on my experience, then this really helps me to identify gaps in my knowledge that I’ll need to fill. That’s about it. If I’m doing ok on the practice exams, then I’ll take the real thing. I’ve found that the practice exams are usually more difficult than then real thing. Oh – one other thing I do related to Microsoft exams – I try to take any beta exams that Microsoft makes available that fall into my skill set. Microsoft has started a blog to announce these and the seats usually fill up really quick. The blog is at http://blogs.technet.com/betaexams/ . You don’t get your results instantly, like a normal exam, instead you have to wait for everyone to finish taking the beta exams and for Microsoft to determine which questions they are using and which they are dropping. So, be prepared to wait six to eight weeks for your results.

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EMEA Analytics & Data Integration Oracle Partner Forum

- by milomir.vojvodic

MONDAY 12TH NOVEMBER, 2012 IN LONDON (UK) For Oracle Partners across Europe, Middle East and Africa: come to hear the latest news from Oracle OpenWorld about Oracle BI & Data Integration, and propel your business growth as an Oracle partner. This event should appeal to BI or Data Integration specialized partners, Executives, Sales, Pre-sales and Solution architects: with a choice of participation in the plenary day and then a set of special interest (technical) sessions. The follow on breakout sessions from the 13th November provide deeper dives and technical training for those of you who wish to stay for more detailed and hands-on workshops. Keynote: Andrew Sutherland, SVP Oracle Technology Hot agenda items will include: The Fusion Middleware Stack: Engineered to work together A complete Analytics and Data Integration Solution Architecture: Big Data and Little Data combined In-Memory Analytics for Extreme Insight Latest Product Development Roadmap for Data Integration and Analytics Venue: Oracles London CITY Moorgate Offices Places are limited, Register from this Link Note: Registration for the conference and the deeper dives and technical training is free of charge to OPN member Partners, but you will be responsible for your own travel and hotel expenses. Event Schedule During this event you can learn about partner success stories, participate in an array of break-out sessions, exchange information with other partners and enjoy a vibrant panel discussion. Nov. 12th : Day 1 Main Plenary Session : Full day, starting 10.30 am. Oracle Hosted Dinner in the Evening Nov. 13th onwards Architecture Masterclass : IM Reference Architecture – Big Data and Little Data combined (1 day) BI-Apps Bootcamp (4-days) Oracle GoldenGate workshop (1 day) Oracle Data Integrator and Oracle Enterprise Data Quality workshop (1 day) For further information and detail download the Agenda (pdf) or contact Michael Hallett at [email protected] and Milomir Vojvodic at [email protected] v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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django/python: is one view that handles two separate models a good idea?

- by clime

I am using django multi-table inheritance: Video and Image are models derived from Media. I have implemented two views: video_list and image_list, which are just proxies to media_list. media_list returns images or videos (based on input parameter model) for a certain object, which can be of type Event, Member, or Crag. It alters its behaviour based on input parameter action, which can be either "edit" or "view". The problem is that I need to ask whether the input parameter model contains Video or Image in media_list so that I can do the right thing. Similar condition is also in helper method media_edit_list that is called from the view. I don't particularly like it but the only alternative I can think of is to have separate logic for video_list and image_list and then probably also separate helper methods for videos and images: video_edit_list, image_edit_list, video_view_list, image_view_list. So four functions instead of just two. That I like even less because the video functions would be very similar to the respective image functions. What do you recommend? Here is extract of relevant parts: http://pastebin.com/07t4bdza. I'll also paste the code here: #urls url(r'^media/images/(?P<rel_model_tag>(event|member|crag))/(?P<rel_object_id>\d+)/(?P<action>(view|edit))/$', views.video_list, name='image-list') url(r'^media/videos/(?P<rel_model_tag>(event|member|crag))/(?P<rel_object_id>\d+)/(?P<action>(view|edit))/$', views.image_list, name='video-list') #views def image_list(request, rel_model_tag, rel_object_id, action): return media_list(request, Image, rel_model_tag, rel_object_id, action) def video_list(request, rel_model_tag, rel_object_id, action): return media_list(request, Video, rel_model_tag, rel_object_id, action) def media_list(request, model, rel_model_tag, rel_object_id, action): rel_model = tag_to_model(rel_model_tag) rel_object = get_object_or_404(rel_model, pk=rel_object_id) if model == Image: star_media = rel_object.star_image else: star_media = rel_object.star_video filter_params = {} if rel_model == Event: filter_params['media__event'] = rel_object_id elif rel_model == Member: filter_params['media__members'] = rel_object_id elif rel_model == Crag: filter_params['media__crag'] = rel_object_id media_list = model.objects.filter(~Q(id=star_media.id)).filter(**filter_params).order_by('media__date_added').all() context = { 'media_list': media_list, 'star_media': star_media, } if action == 'edit': return media_edit_list(request, model, rel_model_tag, rel_model_id, context) return media_view_list(request, model, rel_model_tag, rel_model_id, context) def media_view_list(request, model, rel_model_tag, rel_object_id, context): if request.is_ajax(): context['base_template'] = 'boxes/base-lite.html' return render(request, 'media/list-items.html', context) def media_edit_list(request, model, rel_model_tag, rel_object_id, context): if model == Image: get_media_record = get_image_record else: get_media_record = get_video_record media_list = [get_media_record(media, rel_model_tag, rel_object_id) for media in context['media_list']] if context['star_media']: star_media = get_media_record(star_media, rel_model_tag, rel_object_id) star_media['starred'] = True else: star_media = None json = simplejson.dumps({ 'star_media': star_media, 'media_list': media_list, }) return HttpResponse(json, content_type=json_response_mimetype(request)) # models class Media(models.Model, WebModel): title = models.CharField('title', max_length=128, default='', db_index=True, blank=True) event = models.ForeignKey(Event, null=True, default=None, blank=True) crag = models.ForeignKey(Crag, null=True, default=None, blank=True) members = models.ManyToManyField(Member, blank=True) added_by = models.ForeignKey(Member, related_name='added_images') date_added = models.DateTimeField('date added', auto_now_add=True, null=True, default=None, editable=False) def __unicode__(self): return self.title def get_absolute_url(self): return self.image.url if self.image else self.video.embed_url class Image(Media): image = ProcessedImageField(upload_to='uploads', processors=[ResizeToFit(width=1024, height=1024, upscale=False)], format='JPEG', options={'quality': 75}) thumbnail_1 = ImageSpecField(source='image', processors=[SmartResize(width=178, height=134)], format='JPEG', options={'quality': 75}) thumbnail_2 = ImageSpecField(source='image', #processors=[SmartResize(width=256, height=192)], processors=[ResizeToFit(height=164)], format='JPEG', options={'quality': 75}) class Video(Media): url = models.URLField('url', max_length=256, default='') embed_url = models.URLField('embed url', max_length=256, default='', blank=True) author = models.CharField('author', max_length=64, default='', blank=True) thumbnail = ProcessedImageField(upload_to='uploads', processors=[ResizeToFit(width=1024, height=1024, upscale=False)], format='JPEG', options={'quality': 75}, null=True, default=None, blank=True) thumbnail_1 = ImageSpecField(source='thumbnail', processors=[SmartResize(width=178, height=134)], format='JPEG', options={'quality': 75}) thumbnail_2 = ImageSpecField(source='thumbnail', #processors=[SmartResize(width=256, height=192)], processors=[ResizeToFit(height=164)], format='JPEG', options={'quality': 75}) class Crag(models.Model, WebModel): name = models.CharField('name', max_length=64, default='', db_index=True) normalized_name = models.CharField('normalized name', max_length=64, default='', editable=False) type = models.IntegerField('crag type', null=True, default=None, choices=crag_types) description = models.TextField('description', default='', blank=True) country = models.ForeignKey('country', null=True, default=None) #TODO: make this not null when db enables it latitude = models.FloatField('latitude', null=True, default=None) longitude = models.FloatField('longitude', null=True, default=None) location_index = FixedCharField('location index', length=24, default='', editable=False, db_index=True) # handled by db, used for marker clustering added_by = models.ForeignKey('member', null=True, default=None) #route_count = models.IntegerField('route count', null=True, default=None, editable=False) date_created = models.DateTimeField('date created', auto_now_add=True, null=True, default=None, editable=False) last_modified = models.DateTimeField('last modified', auto_now=True, null=True, default=None, editable=False) star_image = models.OneToOneField('Image', null=True, default=None, related_name='star_crags', on_delete=models.SET_NULL) star_video = models.OneToOneField('Video', null=True, default=None, related_name='star_crags', on_delete=models.SET_NULL)

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A* algorithm very slow

- by Amaranth

I have an programming a RTS game (I use XNA with C#). The pathfinding is working fine, except that when it has a lot of node to search in, there is a lag period of one or two seconds, it happens mainly when there is no path to the target destination, since it that situation there is more nodes to explore. I have the same problem when the path is shorter but selected more than 3 units (can't take the same path since the selected units can be in different part of the map). private List<NodeInfo> FindPath(Unit u, NodeInfo start, NodeInfo end) { Map map = GameInfo.GetInstance().GameMap; _nearestToTarget = start; start.MoveCost = 0; Vector2 endPosition = map.getTileByPos(end.X, end.Y).Position; //getTileByPos simply gets the tile in a 2D array with the X and Y indexes start.EstimatedRemainingCost = (int)(endPosition - map.getTileByPos(start.X, start.Y).Position).Length(); start.Parent = null; List<NodeInfo> openedNodes = new List<NodeInfo>(); ; List<NodeInfo> closedNodes = new List<NodeInfo>(); Point[] movements = GetMovements(u.UnitType); openedNodes.Add(start); while (!closedNodes.Contains(end) && openedNodes.Count > 0) { //Loop in nodes to find lowest cost NodeInfo currentNode = FindLowestCostOpenedNode(openedNodes); openedNodes.Remove(currentNode); closedNodes.Add(currentNode); Vector2 previousMouvement; if (currentNode.Parent == null) { previousMouvement = ConvertRotationToDirectionVector(u.Rotation); } else { previousMouvement = map.getTileByPos(currentNode.X, currentNode.Y).Position - map.getTileByPos(currentNode.Parent.X, currentNode.Parent.Y).Position; previousMouvement.Normalize(); } //For each neighbor foreach (Point movement in movements) { Point exploredGridPos = new Point(currentNode.X + movement.X, currentNode.Y + movement.Y); //Checks if valid move and checks if not if closed nodes list if (ValidNavigableNode(u.UnitType, new Point(currentNode.X, currentNode.Y), exploredGridPos) && !closedNodes.Contains(_gridMap[exploredGridPos.Y, exploredGridPos.X])) { NodeInfo exploredNode = _gridMap[exploredGridPos.Y, exploredGridPos.X]; Tile.TileType exploredTerrain = map.getTileByPos(exploredGridPos.X, exploredGridPos.Y).TerrainType; if(openedNodes.Contains(exploredNode)) { int newCost = currentNode.MoveCost + GetMoveCost(previousMouvement, movement, exploredTerrain); if (newCost < exploredNode.MoveCost) { exploredNode.Parent = currentNode; exploredNode.MoveCost = newCost; //Find nearest tile to the target (in case doesn't find path to target) //Only compares the node to the current nearest FindNearest(exploredNode); } } else { exploredNode.Parent = currentNode; exploredNode.MoveCost = currentNode.MoveCost + GetMoveCost(previousMouvement, movement, exploredTerrain); Vector2 exploredNodeWorldPos = map.getTileByPos(exploredGridPos.X, exploredGridPos.Y).Position; exploredNode.EstimatedRemainingCost = (int)(endPosition - exploredNodeWorldPos).Length(); //Find nearest tile to the target (in case doesn't find path to target) //Only compares the node to the current nearest FindNearest(exploredNode); openedNodes.Add(exploredNode); } } } } return closedNodes; } After that, I simply check if the end node is contained in the returned nodes. If so, I add the end node and each parent until I reach the start. If not, I add the nearestToTarget and each parent until I reach the start. I added a condition before calling FindPath so that only one unit can call a find path each frame (60 frame per second), but it makes no difference. I thought maybe I could solve this by allowing the find path to run in background while the game continues to run correctly, even if it takes a few frame (it is currently sequential sonce it is called in the update() of the unit if there's a target location but no path), but I don't really know how... I also though about sorting my opened nodes list by cost so I don't have to loop them, but I don't know if that would have an effect on the performance... Would there be other solutions? P.S. In the code, when I get the Move Cost, I check if the unit has to turn to perform the move, and the terrain type, nothing hard to do.

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What's new in Servlet 3.1 ? - Java EE 7 moving forward

- by arungupta

Servlet 3.0 was released as part of Java EE 6 and made huge changes focused at ease-of-use. The idea was to leverage the latest language features such as annotations and generics and modernize how Servlets can be written. The web.xml was made as optional as possible. Servet 3.1 (JSR 340), scheduled to be part of Java EE 7, is an incremental release focusing on couple of key features and some clarifications in the specification. The main features of Servlet 3.1 are explained below: Non-blocking I/O - Servlet 3.0 allowed asynchronous request processing but only traditional I/O was permitted. This can restrict scalability of your applications. Non-blocking I/O allow to build scalable applications. TOTD #188 provide more details about how non-blocking I/O can be done using Servlet 3.1. HTTP protocol upgrade mechanism - Section 14.42 in the HTTP 1.1 specification (RFC 2616) defines an upgrade mechanism that allows to transition from HTTP 1.1 to some other, incompatible protocol. The capabilities and nature of the application-layer communication after the protocol change is entirely dependent upon the new protocol chosen. After an upgrade is negotiated between the client and the server, the subsequent requests use the new chosen protocol for message exchanges. A typical example is how WebSocket protocol is upgraded from HTTP as described in Opening Handshake section of RFC 6455. The decision to upgrade is made in Servlet.service method. This is achieved by adding a new method: HttpServletRequest.upgrade and two new interfaces: javax.servlet.http.HttpUpgradeHandler and javax.servlet.http.WebConnection. TyrusHttpUpgradeHandler shows how WebSocket protocol upgrade is done in Tyrus (Reference Implementation for Java API for WebSocket). Security enhancements Applying run-as security roles to #init and #destroy methods Session fixation attack by adding HttpServletRequest.changeSessionId and a new interface HttpSessionIdListener. You can listen for any session id changes using these methods. Default security semantic for non-specified HTTP method in <security-constraint> Clarifying the semantics if a parameter is specified in the URI and payload Miscellaneous ServletResponse.reset clears any data that exists in the buffer as well as the status code, headers. In addition, Servlet 3.1 will also clears the state of calling getServletOutputStream or getWriter. ServletResponse.setCharacterEncoding: Sets the character encoding (MIME charset) of the response being sent to the client, for example, to UTF-8. Relative protocol URL can be specified in HttpServletResponse.sendRedirect. This will allow a URL to be specified without a scheme. That means instead of specifying "http://anotherhost.com/foo/bar.jsp" as a redirect address, "//anotherhost.com/foo/bar.jsp" can be specified. In this case the scheme of the corresponding request will be used. Clarification in HttpServletRequest.getPart and .getParts without multipart configuration. Clarification that ServletContainerInitializer is independent of metadata-complete and is instantiated per web application. A complete replay of What's New in Servlet 3.1: An Overview from JavaOne 2012 can be seen here (click on CON6793_mp4_6793_001 in Media). Each feature will be added to the JSR subject to EG approval. You can share your feedback to [email protected]. Here are some more references for you: Servlet 3.1 Public Review Candidate Downloads Servlet 3.1 PR Candidate Spec Servlet 3.1 PR Candidate Javadocs Servlet Specification Project JSR Expert Group Discussion Archive Java EE 7 Specification Status Several features have already been integrated in GlassFish 4 Promoted Builds. Have you tried any of them ? Here are some other Java EE 7 primers published so far: Concurrency Utilities for Java EE (JSR 236) Collaborative Whiteboard using WebSocket in GlassFish 4 (TOTD #189) Non-blocking I/O using Servlet 3.1 (TOTD #188) What's New in EJB 3.2 ? JPA 2.1 Schema Generation (TOTD #187) WebSocket Applications using Java (JSR 356) Jersey 2 in GlassFish 4 (TOTD #182) WebSocket and Java EE 7 (TOTD #181) Java API for JSON Processing (JSR 353) JMS 2.0 Early Draft (JSR 343) And of course, more on their way! Do you want to see any particular one first ?

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Broken Views

- by Ajarn Mark Caldwell

“SELECT *” isn’t just hazardous to performance, it can actually return blatantly wrong information. There are a number of blog posts and articles out there that actively discourage the use of the SELECT * FROM …syntax. The two most common explanations that I have seen are: Performance: The SELECT * syntax will return every column in the table, but frequently you really only need a few of the columns, and so by using SELECT * your are retrieving large volumes of data that you don’t need, but the system has to process, marshal across tiers, and so on. It would be much more efficient to only select the specific columns that you need. Future-proof: If you are taking other shortcuts in your code, along with using SELECT *, you are setting yourself up for trouble down the road when enhancements are made to the system. For example, if you use SELECT * to return results from a table into a DataTable in .NET, and then reference columns positionally (e.g. myDataRow[5]) you could end up with bad data if someone happens to add a column into position 3 and skewing all the remaining columns’ ordinal position. Or if you use INSERT…SELECT * then you will likely run into errors when a new column is added to the source table in any position. And if you use SELECT * in the definition of a view, you will run into a variation of the future-proof problem mentioned above. One of the guys on my team, Mike Byther, ran across this in a project we were doing, but fortunately he caught it while we were still in development. I asked him to put together a test to prove that this was related to the use of SELECT * and not some other anomaly. I’ll walk you through the test script so you can see for yourself what happens. We are going to create a table and two views that are based on that table, one of them uses SELECT * and the other explicitly lists the column names. The script to create these objects is listed below. IF OBJECT_ID('testtab') IS NOT NULL DROP TABLE testtabgoIF OBJECT_ID('testtab_vw') IS NOT NULL DROP VIEW testtab_vwgo IF OBJECT_ID('testtab_vw_named') IS NOT NULL DROP VIEW testtab_vw_namedgo CREATE TABLE testtab (col1 NVARCHAR(5) null, col2 NVARCHAR(5) null)INSERT INTO testtab(col1, col2)VALUES ('A','B'), ('A','B')GOCREATE VIEW testtab_vw AS SELECT * FROM testtabGOCREATE VIEW testtab_vw_named AS SELECT col1, col2 FROM testtabgo Now, to prove that the two views currently return equivalent results, select from them. SELECT 'star', col1, col2 FROM testtab_vwSELECT 'named', col1, col2 FROM testtab_vw_named OK, so far, so good. Now, what happens if someone makes a change to the definition of the underlying table, and that change results in a new column being inserted between the two existing columns? (Side note, I normally prefer to append new columns to the end of the table definition, but some people like to keep their columns alphabetized, and for clarity for later people reviewing the schema, it may make sense to group certain columns together. Whatever the reason, it sometimes happens, and you need to protect yourself and your code from the repercussions.) DROP TABLE testtabgoCREATE TABLE testtab (col1 NVARCHAR(5) null, col3 NVARCHAR(5) NULL, col2 NVARCHAR(5) null)INSERT INTO testtab(col1, col3, col2)VALUES ('A','C','B'), ('A','C','B')goSELECT 'star', col1, col2 FROM testtab_vwSELECT 'named', col1, col2 FROM testtab_vw_named I would have expected that the view using SELECT * in its definition would essentially pass-through the column name and still retrieve the correct data, but that is not what happens. When you run our two select statements again, you see that the View that is based on SELECT * actually retrieves the data based on the ordinal position of the columns at the time that the view was created. Sure, one work-around is to recreate the View, but you can’t really count on other developers to know the dependencies you have built-in, and they won’t necessarily recreate the view when they refactor the table. I am sure that there are reasons and justifications for why Views behave this way, but I find it particularly disturbing that you can have code asking for col2, but actually be receiving data from col3. By the way, for the record, this entire scenario and accompanying test script apply to SQL Server 2008 R2 with Service Pack 1. So, let the developer beware…know what assumptions are in effect around your code, and keep on discouraging people from using SELECT * syntax in anything but the simplest of ad-hoc queries. And of course, let’s clean up after ourselves. To eliminate the database objects created during this test, run the following commands. DROP TABLE testtabDROP VIEW testtab_vwDROP VIEW testtab_vw_named

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