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• Oracle MAA Part 1: When One Size Does Not Fit All

  - by JoeMeeks

  The good news is that Oracle Maximum Availability Architecture (MAA) best practices combined with Oracle Database 12c (see video) introduce first-in-the-industry database capabilities that truly make unplanned outages and planned maintenance transparent to users. The trouble with such good news is that Oracle’s enthusiasm in evangelizing its latest innovations may leave some to wonder if we’ve lost sight of the fact that not all database applications are created equal. Afterall, many databases don’t have the business requirements for high availability and data protection that require all of Oracle’s ‘stuff’. For many real world applications, a controlled amount of downtime and/or data loss is OK if it saves money and effort. Well, not to worry. Oracle knows that enterprises need solutions that address the full continuum of requirements for data protection and availability. Oracle MAA accomplishes this by defining four HA service level tiers: BRONZE, SILVER, GOLD and PLATINUM. The figure below shows the progression in service levels provided by each tier. Each tier uses a different MAA reference architecture to deploy the optimal set of Oracle HA capabilities that reliably achieve a given service level (SLA) at the lowest cost.  Each tier includes all of the capabilities of the previous tier and builds upon the architecture to handle an expanded fault domain. Bronze is appropriate for databases where simple restart or restore from backup is ‘HA enough’. Bronze is based upon a single instance Oracle Database with MAA best practices that use the many capabilities for data protection and HA included with every Oracle Enterprise Edition license. Oracle-optimized backups using Oracle Recovery Manager (RMAN) provide data protection and are used to restore availability should an outage prevent the database from being able to restart. Silver provides an additional level of HA for databases that require minimal or zero downtime in the event of database instance or server failure as well as many types of planned maintenance. Silver adds clustering technology - either Oracle RAC or RAC One Node. RMAN provides database-optimized backups to protect data and restore availability should an outage prevent the cluster from being able to restart. Gold raises the game substantially for business critical applications that can’t accept vulnerability to single points-of-failure. Gold adds database-aware replication technologies, Active Data Guard and Oracle GoldenGate, which synchronize one or more replicas of the production database to provide real time data protection and availability. Database-aware replication greatly increases HA and data protection beyond what is possible with storage replication technologies. It also reduces cost while improving return on investment by actively utilizing all replicas at all times. Platinum introduces all of the sexy new Oracle Database 12c capabilities that Oracle staff will gush over with great enthusiasm. These capabilities include Application Continuity for reliable replay of in-flight transactions that masks outages from users; Active Data Guard Far Sync for zero data loss protection at any distance; new Oracle GoldenGate enhancements for zero downtime upgrades and migrations; and Global Data Services for automated service management and workload balancing in replicated database environments. Each of these technologies requires additional effort to implement. But they deliver substantial value for your most critical applications where downtime and data loss are not an option. The MAA reference architectures are inherently designed to address conflicting realities. On one hand, not every application has the same objectives for availability and data protection – the Not One Size Fits All title of this blog post. On the other hand, standard infrastructure is an operational requirement and a business necessity in order to reduce complexity and cost. MAA reference architectures address both realities by providing a standard infrastructure optimized for Oracle Database that enables you to dial-in the level of HA appropriate for different service level requirements. This makes it simple to move a database from one HA tier to the next should business requirements change, or from one hardware platform to another – whether it’s your favorite non-Oracle vendor or an Oracle Engineered System. Please stay tuned for additional blog posts in this series that dive into the details of each MAA reference architecture. Meanwhile, more information on Oracle HA solutions and the Maximum Availability Architecture can be found at: Oracle Maximum Availability Architecture - Webcast Maximize Availability with Oracle Database 12c - Technical White Paper

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• Lead, Follow, or Get out of the way

  - by Daniel Moth

  This is one of the sayings (attributed to Thomas Paine) that totally resonated with me from the first time I heard it, which was only 3 years ago during some training course at work: "Lead, Follow, or Get out of the way" You'll find many books with this title and you'll find it quoted by politicians and other leaders in various countries at various times... the quote is open to interpretation and works on many levels. To set the tone of what this means to me, I'll use a simple micro example: In any given conversation, you are either leading it or following it, at different times/snapshots of the conversation. If you are not willing or able to lead it, and you are not willing or able to follow it, then you should depart. The bad alternative which this guidance encourages you NOT to do is to stick around and obstruct progress by not following, not leading, and simply complaining or trying to derail the discussion in no particular direction. The same pattern applies at your position/role at work. Either follow your management/leadership team, or try to lead them to what you think is a better place, or change jobs. Don't stick around complaining about the direction things are going, while not actively trying to either change things or make peace with it. In the previous paragraph you can replace the word "your management" with "the people reporting to you" and the guidance still holds. Either lead your direct reports to where you think they should go, or follow their lead, or change jobs. Complaining about folks not taking direction while doing nothing is not a maintainable state. To me this quote is not about a permanent state, it is not about some people always leading and some always following: It is about a role/hat that anybody can play/wear at any given moment. One minute I am leading you, the next I am following you, and the next we are both following someone else and so on... When there is disagreement, debate the different directions for as long as it takes for you to be comfortable that you can either follow or lead. If you don't become comfortable with either of those, get out of the way. Something to remember is that it is impossible to learn how to lead well, without learning how to follow well (probably deserves its own blog entry)... Things go wrong when someone thinks that they must always be leading, or when everybody wants to follow and nobody steps up to lead... Things go wrong when more than one person wants to lead and they don't try to reach agreement on a shared direction, stubbornly sticking to their guns pulling the rest of the team in multiple directions... Things go wrong when more than one person wants to lead and after numerous and lengthy discussions, none of them decides to follow or get out of the way... Things go wrong when people don't want to lead, don't want to follow, and insist on sticking around... While there are a few ways things that can go wrong as enumerated in the previous paragraph, the most common one in my experience is the last one I mentioned. You'll recognize these folks as the ones that always complain about everything that is wrong with their company/product but do nothing about it. Every time you hear someone giving feedback on how something is wrong or suboptimal, ask them "So now that you identified the problem, what do you think the solution is and what are you doing to drive us to that solution?" The next time things start going wrong, step up and remind everyone: Lead, Follow, or Get out of the way. For more perspectives, and for input to help you form your own interpretation, search the web for this phrase to see in what contexts it is being used (bing, google). Finally, regardless of your political views, I hope you can appreciate if only as an example this perspective of someone leading by actually getting out of the way. Comments about this post by Daniel Moth welcome at the original blog.

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• ArchBeat Link-o-Rama Top 10 for October 2012

  - by Bob Rhubart

  The Top 10 most popular items shared on the OTN ArchBeat Facebook Page for October 2012. OAM/OVD JVM Tuning | @FusionSecExpert Vinay from the Oracle Fusion Middleware Architecture Group (known as the A-Team) shares a process for analyzing and improving performance in Oracle Virtual Directory and Oracle Access Manager. SOA Galore: New Books for Technical Eyes Only Shake up up your technical skills with this trio of new technical books from community members covering SOA and BPM. Clustering ODI11g for High-Availability Part 1: Introduction and Architecture | Richard Yeardley "JEE agents can be deployed alongside, or instead of, standalone agents," says Rittman Meade's Richard Yeardley. "But there is one key advantage in using JEE agents and WebLogic – when you deploy JEE agents as part of a WebLogic cluster they can be configured together to form a high availability cluster." Learn more in Yeardley's extensive post. Solving Big Problems in Our 21st Century Information Society | Irving Wladawsky-Berger "I believe that the kind of extensive collaboration between the private sector, academia and government represented by the Internet revolution will be the way we will generally tackle big problems in the 21st century. Just as with the Internet, governments have a major role to play as the catalyst for many of the big projects that the private sector will then take forward and exploit. The need for high bandwidth, robust national broadband infrastructures is but one such example." -- Irving Wladawsky-Berger Eventually, 90% of tech budgets will be outside IT departments | ZDNet Another interesting post from ZDNet blogger Joe McKendrick about changing roles in IT. ADF Mobile - Login Functionality | Andrejus Baranovskis "The new ADF Mobile approach with native deployment is cool when you want to access phone functionality (camera, email, sms and etc.), also when you want to build mobile applications with advanced UI," reports Oracle ACE Director Andrejus Baranovskis. Podcast: Are You Future Proof? - Part 2 In Part 2, practicing architects and Oracle ACE Directors Ron Batra (AT&T), Basheer Khan (Innowave Technology), and Ronald van Luttikhuizen (Vennster) discuss re-tooling one’s skill set to reflect changes in enterprise IT, including the knowledge to steer stakeholders around the hype to what's truly valuable. ADF Mobile Custom Javascript — iFrame Injection | John Brunswick The ADF Mobile Framework provides a range of out of the box components to add within your AMX pages, according to John Brunswick. But what happens when "an out of the box component does not directly fulfill your development need? What options are available to extend your application interface?" John has an answer. Oracle Solaris 11.1 update focuses on database integration, cloud | Mark Fontecchio TechTarget editor Mark Fontecchio reports on the recent Oracle Solaris 11.1 release, with comments from IDC's Al Gillen. Architects Matter: Making sense of the people who make sense of enterprise IT Why do architects matter? Oracle Enterprise Architect Eric Stephens suggests that you ask yourself this question the next time you take the elevator to the Oracle offices on the 45th floor of the Willis Tower in Chicago, Illinois (or any other skyscraper, for that matter). If you had to take the stairs to get to those offices, who would you blame? "You get the picture," he says. "Architecture is essential for any necessarily complex structure, be it a building or an enterprise." (Read the article) Thought for the Day "I will contend that conceptual integrity is the most important consideration in system design. It is better to have a system omit certain anomalous features and improvements, but to reflect one set of design ideas, than to have one that contains many good but independent and uncoordinated ideas." — Frederick P. Brooks Source: SoftwareQuotes.com

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• Webcast Q&A: ResCare Solves Content Lifecycle Challenges with Oracle WebCenter

  - by Kellsey Ruppel

  Last week we had the fourth webcast in our WebCenter in Action webcast series, "ResCare Solves Content Lifecycle Challenges with Oracle WebCenter", where customer Joe Lichtefeld from ResCare and Wayne Boerger & Doug Thompson from Oracle Partner TEAM Informatics shared how Oracle WebCenter is powering allowing ResCare to solve content lifecycle challenges, reduce compliance and business risks, and increase adoption of intranet as primary business communication tool In case you missed it, here's a recap of the Q&A.   Joe Lichtefeld, ResCare  Q: Did you run into any issues in the deployment of the platform?A: We experienced very few issues when implementing the content management and search functionalities. There were some challenges in determining the metadata structure. We tried to find a fine balance between having enough fields to provide the functionality needed, but trying to limit the impact to the contributing members.  Q: What has been the biggest benefit your end users have seen?A: The biggest benefit to date is two-fold. Content on the intranet can be maintained by the individual contributors more timely than in our old process of all requests being updated by IT. The other big benefit is the ability to find the most current version of a document instead of relying on emails and phone calls to track down the "current" version. Q: Was there any resistance internally when implementing the solution? If so, how did you overcome that?A: We experienced very little resistance. Most of our community groups were eager to be able to contribute and maintain their information. We had the normal hurdles of training and follow-up training with implementing a new system and process. As our second phase rolled out access to all employees, we have received more positive feedback on the accessibility of information. Wayne Boerger & Doug Thompson, TEAM Informatics Q: Can you integrate multiple repositories with the Google Search Appliance? Yes, the Google Search Appliance is designed to index lots of different repositories, from both public and internal sources. There are included connectors to many repositories, such as SharePoint, databases, file systems, LDAP, and with the TEAM GSA Connector and the Oracle Content Server. And the index for these repositories can be configured into different collections depending on the use cases that each customer has, and really, for each need within a customer environment. Q: How many different filters can you add when the search results are returned? A: Presuming this question is about the filtering on the search results. You can add as many filters as you like and it can be done by collection or any number of other criteria. Most importantly, customers now have the ability to limit the returned content by a set metadata value. Q: With the TEAM Sites Connector, what types of content can you sync? A: There’s really no limit; if it can be checked into the content server, then it is eligible for sync into Sites.  So basically, any digital file that has relevance to a Sites implementation can be checked into the WC Content central repository and then the connector can/will manage it. Q: Using the Connector, are there any limitations around where in Sites that synced content can be used? A: There are no limitations about where it can be used. When setting up your environment to use it, you just need to think through the different destinations on the Sites side that might use the content; that way you’ve got the right information to create the rules needed for the connector. If you missed the webcast, be sure to catch the replay to see a live demonstration of WebCenter in action!  ResCare Solves Content Lifecycle Challenges with Oracle WebCenter from Oracle WebCenter

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• Cannot Mount USB 3.0 Hard Disk ?!!

  - by Tenken

  Hi, I have a USB 3.0 external hard disk which I am unable to mount. The entry appears in the "lsusb" command, but I do not exactly understand how to mount it. This is the output for my lsusb command. "ASMedia Technology Inc." is the USB 3.0 device. I would appreciate some help in mounting and accessing the hard disk. This the relevant output of my "lsusb -v" : Bus 009 Device 002: ID 174c:5106 ASMedia Technology Inc. Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x174c ASMedia Technology Inc. idProduct 0x5106 bcdDevice 0.01 iManufacturer 2 ASMedia iProduct 3 AS2105 iSerial 1 00000000000000000000 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 32 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xc0 Self Powered MaxPower 0mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 8 Mass Storage bInterfaceSubClass 6 SCSI bInterfaceProtocol 80 Bulk (Zip) iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Device Qualifier (for other device speed): bLength 10 bDescriptorType 6 bcdUSB 2.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 bNumConfigurations 1 Device Status: 0x0001 Self Powered Bus 009 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 3.00 bDeviceClass 9 Hub bDeviceSubClass 0 Unused bDeviceProtocol 3 bMaxPacketSize0 9 idVendor 0x1d6b Linux Foundation idProduct 0x0003 3.0 root hub bcdDevice 2.06 iManufacturer 3 Linux 2.6.35-28-generic xhci_hcd iProduct 2 xHCI Host Controller iSerial 1 0000:04:00.0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 25 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xe0 Self Powered Remote Wakeup MaxPower 0mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 9 Hub bInterfaceSubClass 0 Unused bInterfaceProtocol 0 Full speed (or root) hub iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0004 1x 4 bytes bInterval 12 Hub Descriptor: bLength 9 bDescriptorType 41 nNbrPorts 4 wHubCharacteristic 0x0009 Per-port power switching Per-port overcurrent protection TT think time 8 FS bits bPwrOn2PwrGood 10 * 2 milli seconds bHubContrCurrent 0 milli Ampere DeviceRemovable 0x00 PortPwrCtrlMask 0xff Hub Port Status: Port 1: 0000.0100 power Port 2: 0000.0100 power Port 3: 0000.0503 highspeed power enable connect Port 4: 0000.0503 highspeed power enable connect Device Status: 0x0003 Self Powered Remote Wakeup Enabled This is the error given when I try to mount the hard drive: shinso@shinso-IdeaPad:~$ sudo mount /dev/sdb /mnt [sudo] password for shinso: mount: /dev/sdb: unknown device This the output of "dmesg|tail": [30062.774178] Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO [30535.800977] usb 9-4: USB disconnect, address 3 [30659.237342] Valid eCryptfs headers not found in file header region or xattr region [30659.237351] Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO [31259.268310] Valid eCryptfs headers not found in file header region or xattr region [31259.268313] Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO [31860.059058] Valid eCryptfs headers not found in file header region or xattr region [31860.059062] Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO [32465.220590] Valid eCryptfs headers not found in file header region or xattr region [32465.220593] Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO I am using Ubuntu 10.10 (64 bit). Any help is appreciated.

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• My collection of favourite TFS utilities

  - by Aaron Kowall

  So, you’re in charge of your company or team’s Team Foundation Server.  Wish it was easier to manage, administer, extend?  Well, here are a few utilities that I highly recommend looking at. I’ve recently had need to rebuild my laptop and upgrade my local TFS environment to TFS 2012 Update 1.  This gave me cause to enumerate some of the utilities I like to have on hand. One of the reasons I love to use TFS on projects is that it’s basically a complete ALM toolkit.  Everything from Task Management, Version Control, Build Management, Test Management, Metrics and Reporting are all there ‘in the box’.  However, no matter how complete a product set it, there are always ways to make it better.  Here are a list of utilities and libraries that are pretty generally useful.  this is not intended to be an exhaustive list of TFS extensions but rather a set that I recommend you look at.  There are many more out there that may be applicable in one scenario or another.  This set of tools should work with TFS 2012 or 2010 if you grab the right version. Most of these tools (and more) are available from the Visual Studio Gallery or CodePlex. General TFS Power Tools – This is ‘the’ collection of utilities and extensions delivered by the Product Group.  Highly recommended from here are the Best Practice Analyzer for ensuring your TFS implementation is healthy and the Team Foundation Server Backups to ensure your TFS databases are backed up correctly. TFS Administrators Toolkit – helps make updates to work item types and reports across many team projects.  Also provides visibility of disk usage by finding large files in version control or test attachments to assist in managing storage utilization. Version Control Git-TF - a set of cross-platform, command line tools that facilitate sharing of changes between TFS and Git. These tools allow a developer to use a local Git repository, and configure it to share changes with a TFS server.  Great for all Git lovers who must integrate into a TFS repository. Testing TFS 2012 Tester Power Tool – A utility for bulk copying test cases which assists in an approach for managing test cases across multiple releases.  A little plug that this utility was written and maintained by Anna Russo of Imaginet where I also work. Test Scribe - A documentation power tool designed to construct documents directly from the TFS for test plan and test run artifacts for the purpose of discussion, reporting etc. Reporting Community TFS Report Extensions - a single repository of SQL Server Reporting Services report for Team Foundation 2010 (and above).  Check out the Test Plan Status report by Imaginet’s Steve St. Jean.  Very valuable for your test managers. Builds TFS Build Manager – A great utility if you are build manager over a complex build environment with many TFS build definitions. Community TFS Build Extensions – contains many custom build activities.  Current release binaries are for TFS 2010 but many of the activities can be recompiled for use with TFS 2012. While compiling this list, I was surprised by the number of TFS utilities and extensions I no longer use/need in TFS 2012 because of the great work by the TFS team addressing many gaps since the 2010 release. Are there any utilities you depend on that I’ve missed?  I’d love to hear about them in the comments!

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• Chalk Talk with John: What Does User Experience Mean to You?

  - by Tanu Sood

  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-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Author: John Brunswick The "Chalk Talk with John" series will explore the practical value of Middleware in the context of two fictional communities, shared through analogies aligned to enterprise technology.  This format offers business stakeholders and IT a common language for understanding the benefits of technology in support of their business initiatives, regardless of their current level of technical knowledge. I will endeavor to showcase an episode highlighting business use cases and how technology plays a role in business on a bi-weekly basis. The debut episode highlights the benefits of user experience capabilities supplied by Portal technologies, by juxtaposing the communities of Middleware Fields and Codeaway Valley with regard to the time and effort their residents spend performing everyday tasks.  This comparison provides insight into the benefits of leveraging a common user experience foundation to support the tasks that our employees, customers and partners engage in on a daily basis with our organizations. Take a look and let me know your thoughts! 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-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} About me: Hi, I am John Brunswick, an Oracle Enterprise Architect. As an Oracle Enterprise Architect, I focus on the alignment of technical capabilities in support of business vision and objectives, as well as the overall business value of technology.  Before coming to Oracle, I was a Practice Manager within BEA System's Business Interaction Division consulting organization, orchestrating enterprise systems in support of line of business goals. Connect with me on Twitter and visit my site for Oracle Fusion Middleware related tips.

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• Good DBAs Do Baselines

  - by Louis Davidson

  One morning, you wake up and feel funny. You can’t quite put your finger on it, but something isn’t quite right. What now? Unless you happen to be a hypochondriac, you likely drag yourself out of bed, get on with the day and gather more “evidence”. You check your symptoms over the next few days; do you feel the same, better, worse? If better, then great, it was some temporal issue, perhaps caused by an allergic reaction to some suspiciously spicy chicken. If the same or worse then you go to the doctor for some health advice, but armed with some data to share, and having ruled out certain possible causes that are fixed with a bit of rest and perhaps an antacid. Whether you realize it or not, in comparing how you feel one day to the next, you have taken baseline measurements. In much the same way, a DBA uses baselines to gauge the gauge health of their database servers. Of course, while SQL Server is very willing to share data regarding its health and activities, it has almost no idea of the difference between good and bad. Over time, experienced DBAs develop “mental” baselines with which they can gauge the health of their servers almost as easily as their own body. They accumulate knowledge of the daily, natural state of each part of their database system, and so know instinctively when one of their databases “feels funny”. Equally, they know when an “issue” is just a passing tremor. They see their SQL Server with all of its four CPU cores running close 100% and don’t panic anymore. Why? It’s 5PM and every day the same thing occurs when the end-of-day reports, which are very CPU intensive, are running. Equally, they know when they need to respond in earnest when it is the first time they have heard about an issue, even if it has been happening every day. Nevertheless, no DBA can retain mental baselines for every characteristic of their systems, so we need to collect physical baselines too. In my experience, surprisingly few DBAs do this very well. Part of the problem is that SQL Server provides a lot of instrumentation. If you look, you will find an almost overwhelming amount of data regarding user activity on your SQL Server instances, and use and abuse of the available CPU, I/O and memory. It seems like a huge task even to work out which data you need to collect, let alone start collecting it on a regular basis, managing its storage over time, and performing detailed comparative analysis. However, without baselines, though, it is very difficult to pinpoint what ails a server, just by looking at a single snapshot of the data, or to spot retrospectively what caused the problem by examining aggregated data for the server, collected over many months. It isn’t as hard as you think to get started. You’ve probably already established some troubleshooting queries of the type SELECT Value FROM SomeSystemTableOrView. Capturing a set of baseline values for such a query can be as easy as changing it as follows: INSERT into BaseLine.SomeSystemTable (value, captureTime) SELECT Value, SYSDATETIME() FROM SomeSystemTableOrView; Of course, there are monitoring tools that will collect and manage this baseline data for you, automatically, and allow you to perform comparison of metrics over different periods. However, to get yourself started and to prove to yourself (or perhaps the person who writes the checks for tools) the value of baselines, stick something similar to the above query into an agent job, running every hour or so, and you are on your way with no excuses! Then, the next time you investigate a slow server, and see x open transactions, y users logged in, and z rows added per hour in the Orders table, compare to your baselines and see immediately what, if anything, has changed!

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• How to get faster graphics in KVM? VNC is painfully slow with Haiku OS guest, Spice won't install and SDL doesn't work

  - by Don Quixote

  I've been coming up to speed on the Haiku operating system, an Open Source clone of BeOS 5 Pro. I'm using an Apple MacBook Pro as my development machine. Apple's BootCamp BIOS does not support more than four partitions on the internal hard drive. While I can set up extended and logical partitions, doing so will prevent any of the installed operating systems from booting. To run Haiku directly on the iron, I boot it off a USB stick. Using external storage is also helpful because I am perpetually out of filesystem space. While VirtualBox is documented to allow access to physical drives, I could not actually get it to work. Also VirtualBox can only use one of the host CPU's cores. While VB guests can be configured for more than one CPU, they are only emulated. A full build of the Haiku OS takes 4.5 under VB. I had the hope of reducing build times by using KVM instead, but it's not working nearly as well as VirtualBox did. The Linux Kernel Virtual Machine is broken in all manner of fundamental ways as seen from Haiku. But I'm a coder; maybe I could contribute to fixing some of those problems. The first problem I've got is that Haiku's video in virt-manager is quite painfully slow. When I drag Haiku windows around the desktop, they lag quite far behind where my mouse is. It's quite difficult to move a window to a precise position on the screen. Just imagine that the mouse was connected to the window title bar with a really stretchy spring. Also Haiku's mouse lags quite far behind where I have moved it. I found lots of Personal Package Archives that enable Spice from QEMU / KVM at the Ubuntu Personal Package Arhives. I tried a few of the PPAs but none of them worked; with one of them, the command "add-apt-repository" crashed with a traceback. There is a Wiki page about Spice, but it says that it only works on 64-bit. My Early 2006 MacBook Pro is 32-bit. Its Apple Model Identifier is MacBookPro1,1; these use Core Duos NOT Core 2 Duos. I don't mind building a source deb for 32-bit if I can expect it to work. Is there some reason that Spice should be 64-bit only? Does it need features of the x86_64 Instruction Set Architecture that x86 does not have? When I try using SDL from virt-manager, the configuration for Local SDL Window says "Xauth: /home/mike/.Xauthority". When I try to start my guest, virt-manager emits an error. When I Googled the error message, the usual solution was to make ~/.Xauthority readible. However, .Xauthorty does not exist in my home directory. Instead I have a $XAUTHORITY environment variable. There is no way to configure SDL in virt-manager to use $XAUTHORITY instead of ~/.Xauthority. Neither does it work to copy the value of $XAUTHORITY into the file. I am ready to scream, because I've been five fscking days trying to make KVM work for Haiku development. There is a whole lot more that is broken than the slow video. All I really want to do for now is speed up my full builds of Haiku by using "jam -j2" to use both cores in my CPU. I may try Xen next, but the last time I monkeyed with Xen it was far, far more broken than I am finding KVM to be. Just for now, I would be satisfied if there were some way to use my USB stick as a drive in VirtualBox. VB does allow me to configure /dev/sdb as a drive, but it always causes a fatal error when I try to launch the guest. Thank You For Any Advice You Can Give Me. -

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• Heterogeneous Datacenter Management with Enterprise Manager 12c

  - by Joe Diemer

  The following is a Guest Blog, contributed by Bryce Kaiser, Product Manager at Blue MedoraWhen I envision a perfect datacenter, it would consist of technologies acquired from a single vendor across the entire server, middleware, application, network, and storage stack - Apps to Disk - that meets your organization’s every IT requirement with absolute best-of-breed solutions in every category.   To quote a familiar motto, your datacenter would consist of "Hardware and Software, Engineered to Work Together".  In almost all cases, practical realities dictate something far less than the IT Utopia mentioned above.   You may wish to leverage multiple vendors to keep licensing costs down, a single vendor may not have an offering in the IT category you need, or your preferred vendor may quite simply not have the solution that meets your needs.    In other words, your IT needs dictate a heterogeneous IT environment.  Heterogeneity, however, comes with additional complexity. The following are two pretty typical challenges:1) No End-to-End Visibility into the Enterprise Wide Application Deployment. Each vendor solution which is added to an infrastructure may bring its own tooling creating different consoles for different vendor applications and platforms.2) No Visibility into Performance Bottlenecks. When multiple management tools operate independently, you lose diagnostic capabilities including identifying cross-tier issues with database, hung-requests, slowness, memory leaks and hardware errors/failures causing DB/MW issues. As adoption of Oracle Enterprise Manager (EM) has increased, especially since the release of Enterprise Manager 12c, Oracle has seen an increase in the number of customers who want to leverage their investments in EM to manage non-Oracle workloads.  Enterprise Manager provides a single pane of glass view into their entire datacenter.  By creating a highly extensible framework via the Oracle EM Extensibility Development Kit (EDK), Oracle has provided the tooling for business partners such as my company Blue Medora as well as customers to easily fill gaps in the ecosystem and enhance existing solutions.  As mentioned in the previous post on the Enterprise Manager Extensibility Exchange, customers have access to an assortment of Oracle and Partner provided solutions through this Exchange, which is accessed at http://www.oracle.com/goto/emextensibility.  Currently, there are over 80 Oracle and partner provided plug-ins across the EM 11g and EM 12c versions.  Blue Medora is one of those contributing partners, for which you will find 3 of our solutions including our flagship plugin for VMware.  Let's look at Blue Medora’s VMware plug-in as an example to what I'm trying to convey.  Here is a common situation solved by true visibility into your entire stack:Symptoms•    My database is bogging down, however the database appears okay internally.  Maybe it’s starved for resources?•    My OS tooling is showing everything is “OK”.  Something doesn’t add up. Root cause•    Through the VMware plugin we can see the problem is actually on the virtualization layer Solution•    From within Enterprise Manager  -- the same tool you use for all of your database tuning -- we can overlay the data of the database target, host target, and virtual machine target for a true picture of the true root cause. Here is the console view: Perhaps your monitoring conditions are more specific to your environment.  No worries, Enterprise Manager still has you covered.  With Metric Extensions you have the “Next Generation” of User-Defined Metrics, which easily bring the power of your existing management scripts into a single console while leveraging the proven Enterprise Manager framework. Simply put, Oracle Enterprise manager boasts a growing ecosystem that provides the single pane of glass for your entire datacenter from the database and beyond.  Bryce can be contacted at [email protected]

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• The Best Data Integration for Exadata Comes from Oracle

  - by maria costanzo

  Oracle Data Integrator and Oracle GoldenGate offer unique and optimized data integration solutions for Oracle Exadata. For example, customers that choose to feed their data warehouse or reporting database with near real-time throughout the day, can do so without decreasing  performance or availability of source and target systems. And if you ask why real-time, the short answer is: in today’s fast-paced, always-on world, business decisions need to use more relevant, timely data to be able to act fast and seize opportunities. A longer response to "why real-time" question can be found in a related blog post. If we look at the solution architecture, as shown on the diagram below,  Oracle Data Integrator and Oracle GoldenGate are both uniquely designed to take full advantage of the power of the database and to eliminate unnecessary middle-tier components. Oracle Data Integrator (ODI) is the best bulk data loading solution for Exadata. ODI is the only ETL platform that can leverage the full power of Exadata, integrate directly on the Exadata machine without any additional hardware, and by far provides the simplest setup and fastest overall performance on an Exadata system. We regularly see customers achieving a 5-10 times boost when they move their ETL to ODI on Exadata. For  some companies the performance gain is even much higher. For example a large insurance company did a proof of concept comparing ODI vs a traditional ETL tool (one of the market leaders) on Exadata. The same process that was taking 5hrs and 11 minutes to complete using the competing ETL product took 7 minutes and 20 seconds with ODI. Oracle Data Integrator was 42 times faster than the conventional ETL when running on Exadata.This shows that Oracle's own data integration offering helps you to gain the most out of your Exadata investment with a truly optimized solution. GoldenGate is the best solution for streaming data from heterogeneous sources into Exadata in real time. Oracle GoldenGate can also be used together with Data Integrator for hybrid use cases that also demand non-invasive capture, high-speed real time replication. Oracle GoldenGate enables real-time data feeds from heterogeneous sources non-invasively, and delivers to the staging area on the target Exadata system. ODI runs directly on Exadata to use the database engine power to perform in-database transformations. Enterprise Data Quality is integrated with Oracle Data integrator and enables ODI to load trusted data into the data warehouse tables. Only Oracle can offer all these technical benefits wrapped into a single intelligence data warehouse solution that runs on Exadata. Compared to traditional ETL with add-on CDC this solution offers: §  Non-invasive data capture from heterogeneous sources and avoids any performance impact on source §  No mid-tier; set based transformations use database power §  Mini-batches throughout the day –or- bulk processing nightly which means maximum availability for the DW §  Integrated solution with Enterprise Data Quality enables leveraging trusted data in the data warehouse In addition to Starwood Hotels and Resorts, Morrison Supermarkets, United Kingdom’s fourth-largest food retailer, has seen the power of this solution for their new BI platform and shared their story with us. Morrisons needed to analyze data across a large number of manufacturing, warehousing, retail, and financial applications with the goal to achieve single view into operations for improved customer service. The retailer deployed Oracle GoldenGate and Oracle Data Integrator to bring new data into Oracle Exadata in near real-time and replicate the data into reporting structures within the data warehouse—extending visibility into operations. Using Oracle's data integration offering for Exadata, Morrisons produced financial reports in seconds, rather than minutes, and improved staff productivity and agility. You can read more about Morrison’s success story here and hear from Starwood here. From an Irem Radzik article.

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• How to retrieve Sharepoint data from a Windows Forms Application.

  - by Michael M. Bangoy

  In this demo I'm going to demonstrate how to retrieve Sharepoint data and display it on a Windows Forms Application. 1. Open Visual Studio 2010 and create a new Project. 2. In the project template select Windows Forms Application. 3. In order to communicate with Sharepoint from a Windows Forms Application we need to add the 2 Sharepoint Client DLL located in c:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\ISAPI. 4. Select the Microsoft.Sharepoint.Client.dll and Microsoft.Sharepoint.Client.Runtime.dll. That's it we're ready to write our codes. Note: In this example I've added to controls on the form, the controls are Button, TextBox, Label and DataGridView. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Data.Objects; using System.Drawing; using System.Linq; using System.Text; using System.Security; using System.Windows.Forms; using SP = Microsoft.SharePoint.Client; namespace ClientObjectModel { public partial class Form1 : Form { // declare string url of the Sharepoint site string _context = "theurlofyoursharepointsite"; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { } private void getsitetitle() {    SP.ClientContext context = new SP.ClientContext(_context);    SP.Web _site = context.Web;    context.Load(_site);    context.ExecuteQuery();    txttitle.Text = _site.Title;    context.Dispose(); } private void loadlist() { using (SP.ClientContext _clientcontext = new SP.ClientContext(_context)) {    SP.Web _web = _clientcontext.Web;    SP.ListCollection _lists = _clientcontext.Web.Lists;    _clientcontext.Load(_lists);    _clientcontext.ExecuteQuery();    DataTable dt = new DataTable();    DataColumn column;    DataRow row;    column = new DataColumn();    column.DataType = Type.GetType("System.String");    column.ColumnName = "List Title";    dt.Columns.Add(column);    foreach (SP.List listitem in _lists)    {       row = dt.NewRow();       row["List Title"] = listitem.Title;       dt.Rows.Add(row);    }       dataGridView1.DataSource = dt;    } private void cmdload_Click(object sender, EventArgs e) { getsitetitle(); loadlist(); } } That's it. Running the application and clicking the Load Button will retrieve the Title of the Sharepoint site and display it on the TextBox and also it will retrieve ALL of the Sharepoint List on that site and populate the DataGridView with the List Title. Hope this helps. Thank 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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• Caching factory design

  - by max

  I have a factory class XFactory that creates objects of class X. Instances of X are very large, so the main purpose of the factory is to cache them, as transparently to the client code as possible. Objects of class X are immutable, so the following code seems reasonable: # module xfactory.py import x class XFactory: _registry = {} def get_x(self, arg1, arg2, use_cache = True): if use_cache: hash_id = hash((arg1, arg2)) if hash_id in _registry: return _registry[hash_id] obj = x.X(arg1, arg2) _registry[hash_id] = obj return obj # module x.py class X: # ... Is it a good pattern? (I know it's not the actual Factory Pattern.) Is there anything I should change? Now, I find that sometimes I want to cache X objects to disk. I'll use pickle for that purpose, and store as values in the _registry the filenames of the pickled objects instead of references to the objects. Of course, _registry itself would have to be stored persistently (perhaps in a pickle file of its own, in a text file, in a database, or simply by giving pickle files the filenames that contain hash_id). Except now the validity of the cached object depends not only on the parameters passed to get_x(), but also on the version of the code that created these objects. Strictly speaking, even a memory-cached object could become invalid if someone modifies x.py or any of its dependencies, and reloads it while the program is running. So far I ignored this danger since it seems unlikely for my application. But I certainly cannot ignore it when my objects are cached to persistent storage. What can I do? I suppose I could make the hash_id more robust by calculating hash of a tuple that contains arguments arg1 and arg2, as well as the filename and last modified date for x.py and every module and data file that it (recursively) depends on. To help delete cache files that won't ever be useful again, I'd add to the _registry the unhashed representation of the modified dates for each record. But even this solution isn't 100% safe since theoretically someone might load a module dynamically, and I wouldn't know about it from statically analyzing the source code. If I go all out and assume every file in the project is a dependency, the mechanism will still break if some module grabs data from an external website, etc.). In addition, the frequency of changes in x.py and its dependencies is quite high, leading to heavy cache invalidation. Thus, I figured I might as well give up some safety, and only invalidate the cache only when there is an obvious mismatch. This means that class X would have a class-level cache validation identifier that should be changed whenever the developer believes a change happened that should invalidate the cache. (With multiple developers, a separate invalidation identifier is required for each.) This identifier is hashed along with arg1 and arg2 and becomes part of the hash keys stored in _registry. Since developers may forget to update the validation identifier or not realize that they invalidated existing cache, it would seem better to add another validation mechanism: class X can have a method that returns all the known "traits" of X. For instance, if X is a table, I might add the names of all the columns. The hash calculation will include the traits as well. I can write this code, but I am afraid that I'm missing something important; and I'm also wondering if perhaps there's a framework or package that can do all of this stuff already. Ideally, I'd like to combine in-memory and disk-based caching.

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• Cloud Computing Pricing - It's like a Hotel

  - by BuckWoody

  I normally don't go into the economics or pricing side of Distributed Computing, but I've had a few friends that have been surprised by a bill lately and I wanted to quickly address at least one aspect of it. Most folks are used to buying software and owning it outright - like buying a car. We pay a lot for the car, and then we use it whenever we want. We think of the "cloud" services as a taxi - we'll just pay for the ride we take an no more. But it's not quite like that. It's actually more like a hotel. When you subscribe to Azure using a free offering like the MSDN subscription, you don't have to pay anything for the service. But when you create an instance of a Web or Compute Role, Storage, that sort of thing, you can think of the idea of checking into a hotel room. You get the key, you pay for the room. For Azure, using bandwidth, CPU and so on is billed just like it states in the Azure Portal. so in effect there is a cost for the service and then a cost to use it, like water or power or any other utility. Where this bit some folks is that they created an instance, played around with it, and then left it running. No one was using it, no one was on - so they thought they wouldn't be charged. But they were. It wasn't much, but it was a surprise.They had the hotel room key, but they weren't in the room, so to speak. To add to their frustration, they had to talk to someone on the phone to cancel the account. I understand the frustration. Although we have all this spelled out in the sign up area, not everyone has the time to read through all that. I get that. So why not make this easier? As an explanation, we bill for that time because the instance is still running, and we have to tie up resources to be available the second you want them, and that costs money. As far as being able to cancel from the portal, that's also something that needs to be clearer. You may not be aware that you can spin up instances using code - and so cancelling from the Portal would allow you to do the same thing. Since a mistake in code could erase all of your instances and the account, we make you call to make sure you're you and you really want to take it down. Not a perfect system by any means, but we'll evolve this as time goes on. For now, I wanted to make sure you're aware of what you should do. By the way, you don't have to cancel your whole account not to be billed. Just delete the instance from the portal and you won't be charged. You don't have to call anyone for that. And just FYI - you can download the SDK for Azure and never even hit the online version at all for learning and playing around. No sign-up, no credit card, PO, nothing like that. In fact, that's how I demo Azure all the time. Everything runs right on your laptop in an emulated environment.  

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• Managing common code on Windows 7 (.NET) and Windows 8 (WinRT)

  - by ryanabr

  Recent announcements regarding Windows Phone 8 and the fact that it will have the WinRT behind it might make some of this less painful but I  discovered the "XmlDocument" object is in a new location in WinRT and is almost the same as it's brother in .NET System.Xml.XmlDocument (.NET) Windows.Data.Xml.Dom.XmlDocument (WinRT) The problem I am trying to solve is how to work with both types in the code that performs the same task on both Windows Phone 7 and Windows 8 platforms. The first thing I did was define my own XmlNode and XmlNodeList classes that wrap the actual Microsoft objects so that by using the "#if" compiler directive either work with the WinRT version of the type, or the .NET version from the calling code easily. public class XmlNode     { #if WIN8         public Windows.Data.Xml.Dom.IXmlNode Node { get; set; }         public XmlNode(Windows.Data.Xml.Dom.IXmlNode xmlNode)         {             Node = xmlNode;         } #endif #if !WIN8 public System.Xml.XmlNode Node { get; set ; } public XmlNode(System.Xml.XmlNode xmlNode)         {             Node = xmlNode;         } #endif     } public class XmlNodeList     { #if WIN8         public Windows.Data.Xml.Dom.XmlNodeList List { get; set; }         public int Count {get {return (int)List.Count;}}         public XmlNodeList(Windows.Data.Xml.Dom.XmlNodeList list)         {             List = list;         } #endif #if !WIN8 public System.Xml.XmlNodeList List { get; set ; } public int Count { get { return List.Count;}} public XmlNodeList(System.Xml.XmlNodeList list)         {             List = list;        } #endif     } From there I can then use my XmlNode and XmlNodeList in the calling code with out having to clutter the code with all of the additional #if switches. The challenge after this was the code that worked directly with the XMLDocument object needed to be seperate on both platforms since the method for populating the XmlDocument object is completly different on both platforms. To solve this issue. I made partial classes, one partial class for .NET and one for WinRT. Both projects have Links to the Partial Class that contains the code that is the same for the majority of the class, and the partial class contains the code that is unique to the version of the XmlDocument. The files with the little arrow in the lower left corner denotes 'linked files' and are shared in multiple projects but only exist in one location in source control. You can see that the _Win7 partial class is included directly in the project since it include code that is only for the .NET platform, where as it's cousin the _Win8 (not pictured above) has all of the code specific to the _Win8 platform. In the _Win7 partial class is this code: public partial class WUndergroundViewModel     { public static WUndergroundData GetWeatherData( double lat, double lng)         { WUndergroundData data = new WUndergroundData();             System.Net. WebClient c = new System.Net. WebClient(); string req = "http://api.wunderground.com/api/xxx/yesterday/conditions/forecast/q/[LAT],[LNG].xml" ;             req = req.Replace( "[LAT]" , lat.ToString());             req = req.Replace( "[LNG]" , lng.ToString()); XmlDocument doc = new XmlDocument();             doc.Load(c.OpenRead(req)); foreach (XmlNode item in doc.SelectNodes("/response/features/feature" ))             { switch (item.Node.InnerText)                 { case "yesterday" :                         ParseForecast( new FishingControls.XmlNodeList (doc.SelectNodes( "/response/forecast/txt_forecast/forecastdays/forecastday" )), new FishingControls.XmlNodeList (doc.SelectNodes( "/response/forecast/simpleforecast/forecastdays/forecastday" )), data); break ; case "conditions" :                         ParseCurrent( new FishingControls.XmlNode (doc.SelectSingleNode("/response/current_observation" )), data); break ; case "forecast" :                         ParseYesterday( new FishingControls.XmlNodeList (doc.SelectNodes( "/response/history/observations/observation" )),data); break ;                 }             } return data;         }     } in _win8 partial class is this code: public partial class WUndergroundViewModel     { public async static Task< WUndergroundData > GetWeatherData(double lat, double lng)         { WUndergroundData data = new WUndergroundData (); HttpClient c = new HttpClient (); string req = "http://api.wunderground.com/api/xxxx/yesterday/conditions/forecast/q/[LAT],[LNG].xml" ;             req = req.Replace( "[LAT]" , lat.ToString());             req = req.Replace( "[LNG]" , lng.ToString()); HttpResponseMessage msg = await c.GetAsync(req); string stream = await msg.Content.ReadAsStringAsync(); XmlDocument doc = new XmlDocument ();             doc.LoadXml(stream, null); foreach ( IXmlNode item in doc.SelectNodes("/response/features/feature" ))             { switch (item.InnerText)                 { case "yesterday" :                         ParseForecast( new FishingControls.XmlNodeList (doc.SelectNodes( "/response/forecast/txt_forecast/forecastdays/forecastday" )), new FishingControls.XmlNodeList (doc.SelectNodes( "/response/forecast/simpleforecast/forecastdays/forecastday" )), data); break; case "conditions" :                         ParseCurrent( new FishingControls.XmlNode (doc.SelectSingleNode("/response/current_observation" )), data); break; case "forecast" :                         ParseYesterday( new FishingControls.XmlNodeList (doc.SelectNodes( "/response/history/observations/observation")), data); break;                 }             } return data;         }     } Summary: This method allows me to have common 'business' code for both platforms that is pretty clean, and I manage the technology differences separately. Thank you tostringtheory for your suggestion, I was considering that approach.

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• Know your Data Lineage

  - by Simon Elliston Ball

  An academic paper without the footnotes isn’t an academic paper. Journalists wouldn’t base a news article on facts that they can’t verify. So why would anyone publish reports without being able to say where the data has come from and be confident of its quality, in other words, without knowing its lineage. (sometimes referred to as ‘provenance’ or ‘pedigree’) The number and variety of data sources, both traditional and new, increases inexorably. Data comes clean or dirty, processed or raw, unimpeachable or entirely fabricated. On its journey to our report, from its source, the data can travel through a network of interconnected pipes, passing through numerous distinct systems, each managed by different people. At each point along the pipeline, it can be changed, filtered, aggregated and combined. When the data finally emerges, how can we be sure that it is right? How can we be certain that no part of the data collection was based on incorrect assumptions, that key data points haven’t been left out, or that the sources are good? Even when we’re using data science to give us an approximate or probable answer, we cannot have any confidence in the results without confidence in the data from which it came. You need to know what has been done to your data, where it came from, and who is responsible for each stage of the analysis. This information represents your data lineage; it is your stack-trace. If you’re an analyst, suspicious of a number, it tells you why the number is there and how it got there. If you’re a developer, working on a pipeline, it provides the context you need to track down the bug. If you’re a manager, or an auditor, it lets you know the right things are being done. Lineage tracking is part of good data governance. Most audit and lineage systems require you to buy into their whole structure. If you are using Hadoop for your data storage and processing, then tools like Falcon allow you to track lineage, as long as you are using Falcon to write and run the pipeline. It can mean learning a new way of running your jobs (or using some sort of proxy), and even a distinct way of writing your queries. Other Hadoop tools provide a lot of operational and audit information, spread throughout the many logs produced by Hive, Sqoop, MapReduce and all the various moving parts that make up the eco-system. To get a full picture of what’s going on in your Hadoop system you need to capture both Falcon lineage and the data-exhaust of other tools that Falcon can’t orchestrate. However, the problem is bigger even that that. Often, Hadoop is just one piece in a larger processing workflow. The next step of the challenge is how you bind together the lineage metadata describing what happened before and after Hadoop, where ‘after’ could be  a data analysis environment like R, an application, or even directly into an end-user tool such as Tableau or Excel. One possibility is to push as much as you can of your key analytics into Hadoop, but would you give up the power, and familiarity of your existing tools in return for a reliable way of tracking lineage? Lineage and auditing should work consistently, automatically and quietly, allowing users to access their data with any tool they require to use. The real solution, therefore, is to create a consistent method by which to bring lineage data from these data various disparate sources into the data analysis platform that you use, rather than being forced to use the tool that manages the pipeline for the lineage and a different tool for the data analysis. The key is to keep your logs, keep your audit data, from every source, bring them together and use the data analysis tools to trace the paths from raw data to the answer that data analysis provides.

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• Essbase BSO Data Fragmentation

  - by Ann Donahue

  Essbase BSO Data Fragmentation Data fragmentation naturally occurs in Essbase Block Storage (BSO) databases where there are a lot of end user data updates, incremental data loads, many lock and send, and/or many calculations executed.  If an Essbase database starts to experience performance slow-downs, this is an indication that there may be too much fragmentation.  See Chapter 54 Improving Essbase Performance in the Essbase DBA Guide for more details on measuring and eliminating fragmentation: http://docs.oracle.com/cd/E17236_01/epm.1112/esb_dbag/daprcset.html Fragmentation is likely to occur in the following situations: Read/write databases that users are constantly updating data Databases that execute calculations around the clock Databases that frequently update and recalculate dense members Data loads that are poorly designed Databases that contain a significant number of Dynamic Calc and Store members Databases that use an isolation level of uncommitted access with commit block set to zero There are two types of data block fragmentation Free space tracking, which is measured using the Average Fragmentation Quotient statistic. Block order on disk, which is measured using the Average Cluster Ratio statistic. Average Fragmentation Quotient The Average Fragmentation Quotient ratio measures free space in a given database.  As you update and calculate data, empty spaces occur when a block can no longer fit in its original space and will either append at the end of the file or fit in another empty space that is large enough.  These empty spaces take up space in the .PAG files.  The higher the number the more empty spaces you have, therefore, the bigger the .PAG file and the longer it takes to traverse through the .PAG file to get to a particular record.  An Average Fragmentation Quotient value of 3.174765 means the database is 3% fragmented with free space. Average Cluster Ratio Average Cluster Ratio describes the order the blocks actually exist in the database. An Average Cluster Ratio number of 1 means all the blocks are ordered in the correct sequence in the order of the Outline.  As you load data and calculate data blocks, the sequence can start to be out of order.  This is because when you write to a block it may not be able to place back in the exact same spot in the database that it existed before.  The lower this number the more out of order it becomes and the more it affects performance.  An Average Cluster Ratio value of 1 means no fragmentation.  Any value lower than 1 i.e. 0.01032828 means the data blocks are getting further out of order from the outline order. Eliminating Data Block Fragmentation Both types of data block fragmentation can be removed by doing a dense restructure or export/clear/import of the data.  There are two types of dense restructure: 1. Implicit Restructures Implicit dense restructure happens when outline changes are done using EAS Outline Editor or Dimension Build. Essbase restructures create new .PAG files restructuring the data blocks in the .PAG files. When Essbase restructures the data blocks, it regenerates the index automatically so that index entries point to the new data blocks. Empty blocks are NOT removed with implicit restructures. 2. Explicit Restructures Explicit dense restructure happens when a manual initiation of the database restructure is executed. An explicit dense restructure is a full restructure which comprises of a dense restructure as outlined above plus the removal of empty blocks Empty Blocks vs. Fragmentation The existence of empty blocks is not considered fragmentation.  Empty blocks can be created through calc scripts or formulas.  An empty block will add to an existing database block count and will be included in the block counts of the database properties.  There are no statistics for empty blocks.  The only way to determine if empty blocks exist in an Essbase database is to record your current block count, export the entire database, clear the database then import the exported data.  If the block count decreased, the difference is the number of empty blocks that had existed in the database.

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• How much is a subscriber worth?

  - by Tom Lewin

  This year at Red Gate, we’ve started providing a way to back up SQL Azure databases and Azure storage. We decided to sell this as a service, instead of a product, which means customers only pay for what they use. Unfortunately for us, it makes figuring out revenue much trickier. With a product like SQL Compare, a customer pays for it, and it’s theirs for good. Sure, we offer support and upgrades, but, fundamentally, the sale is a simple, upfront transaction: we’ve made this product, you need this product, we swap product for money and everyone is happy. With software as a service, it isn’t that easy. The money and product don’t change hands up front. Instead, we provide a service in exchange for a recurring fee. We know someone buying SQL Compare will pay us $X, but we don’t know how long service customers will stay with us, or how much they will spend. How do we find this out? We use lifetime value analysis. What is lifetime value? Lifetime value, or LTV, is how much a customer is worth to the business. For Entrepreneurs has a brilliant write up that we followed to conduct our analysis. Basically, it all boils down to this equation: LTV = ARPU x ALC To make it a bit less of an alphabet-soup and a bit more understandable, we can write it out in full: The lifetime value of a customer equals the average revenue per customer per month, times the average time a customer spends with the service Simple, right? A customer is worth the average spend times the average stay. If customers pay on average $50/month, and stay on average for ten months, then a new customer will, on average, bring in $500 over the time they are a customer! Average spend is easy to work out; it’s revenue divided by customers. The problem comes when we realise that we don’t know exactly how long a customer will stay with us. How can we figure out the average lifetime of a customer, if we only have six months’ worth of data? The answer lies in the fact that: Average Lifetime of a Customer = 1 / Churn Rate The churn rate is the percentage of customers that cancel in a month. If half of your customers cancel each month, then your average customer lifetime is two months. The problem we faced was that we didn’t have enough data to make an estimate of one month’s cancellations reliable (because barely anybody cancels)! To deal with this data problem, we can take data from the last three months instead. This means we have more data to play with. We can still use the equation above, we just need to multiply the final result by three (as we worked out how many three month periods customers stay for, and we want our answer to be in months). Now these estimates are likely to be fairly unreliable; when there’s not a lot of data it pays to be cautious with inference. That said, the numbers we have look fairly consistent, and it’s super easy to revise our estimates when new data comes in. At the very least, these numbers give us a vague idea of whether a subscription business is viable. As far as Cloud Services goes, the business looks very viable indeed, and the low cancellation rates are much more than just data points in LTV equations; they show that the product is working out great for our customers, which is exactly what we’re looking for!

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• About the K computer

  - by nospam(at)example.com (Joerg Moellenkamp)

  Okay ? after getting yet another mail because of the new #1 on the Top500 list, I want to add some comments from my side: Yes, the system is using SPARC processor. And that is great news for a SPARC fan like me. It is using the SPARC VIIIfx processor from Fujitsu clocked at 2 GHz. No, it isn't the only one. Most people are saying there are two in the Top500 list using SPARC (#77 JAXA and #1 K) but in fact there are three. The Tianhe-1 (#2 on the Top500 list) super computer contains 2048 Galaxy "FT-1000" 1 GHz 8-core processors. Don't know it? The FeiTeng-1000 ? this proc is a 8 core, 8 threads per core, 1 ghz processor made in China. And it's SPARC based. By the way ? this sounds really familiar to me ? perhaps the people just took the opensourced UltraSPARC-T2 design, because some of the parameters sound just to similar. However it looks like that Tianhe-1 is using the SPARCs as input nodes and not as compute notes. No, I don't see it as the next M-series processor. Simple reason: You can't create SMP systems out of them ? it simply hasn't the functionality to do so. Even when there are multiple CPUs on a single board, they are not connected like an SMP/NUMA machine to a shared memory machine ? they are connected with the cluster interconnect (in this case the Tofu interconnect) and work like a large cluster. Yes, it has a lot of oomph in Linpack ? however I assume a lot came from the extensions to the SPARCv9 standard. No, Linpack has no relevance for any commercial workload ? Linpack is such a special load, that even some HPC people are arguing that it isn't really a good benchmark for HPC. It's embarrassingly parallel, it can work with relatively small interconnects compared to the interconnects in SMP systems (however we get in spheres SMP interconnects where a few years ago). Amdahl isn't hitting that hard when running Linpack. Yes, it's a good move to use SPARC. At some time in the last 10 years, there was an interesting twist in perception: SPARC was considered as proprietary architecture and x86 was the open architecture. However it's vice versa ? try to create a x86 clone and you have a lot of intellectual property problems, create a SPARC clone and you have to spend 100 bucks or so to get the specification from the SPARC Foundation and develop your own SPARC processor. Fujitsu is doing this for a long time now. So they had their own processor, their own know-how. So why was SPARC a good choice? Well ? essentially Fujitsu can do what they want with their core as it is their core, for example adding the extensions to the SPARCv9 chipset ? getting Intel to create extensions to x86 to help you with your product is a little bit harder. So Fujitsu could do they needed to do with their processor in order to create such a supercomputer. No, the K is really using no FPGA or GPU as accelerators. The K is really using the CPU at doing this job. Yes, it has a significantly enhanced FPU capable to execute 8 instructions in parallel. No, it doesn't run Solaris. Yes, it uses Linux. No, it doesn't hurt me ... as my colleague Roland Rambau (he knows a lot about HPC) said once to me ... it doesn't matter which OS is staying out of the way of the workload in HPC.

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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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• Oracle at ARM TechCon

  - by Tori Wieldt

  ARM TechCon is a technical conference for hardware and software engineers, Oct. 30-Nov 1 in Santa Clara, California. Days two and three of the conference will be geared towards systems designers and software developers, those interested in building ARM processor-based modules, boards, and systems. It will cover all of the hardware and software, tools, ranging from low-power design, networking and connectivity, open source software, and security. Oracle is a sponsor of ARM TechCon, and will present three Java sessions and a hands-on-lab:  "Do You Like Coffee with Your Dessert? Java and the Raspberry Pi" - The Raspberry Pi, an ARM-powered single board computer running a full Linux distro off an SD card has caused a huge wave of interest among developers. This session looks at how Java can be used on a device such as this. Using Java SE for embedded devices and a port of JavaFX, the presentation includes a variety of demonstrations of what the Raspberry Pi is capable of. The Raspberry Pi also provides GPIO line access, and the session covers how this can be used from Java applications. Prepare to be amazed at what this tiny board can do. (Angela Caicedo, Java Evangelist) "Modernizing the Explosion of Advanced Microcontrollers with Embedded Java" - This session explains why Oracle Java ME Embedded is the right choice for building small, connected, and intelligent embedded solutions, such as industrial control applications, smart sensing, wireless connectivity, e-health, or general machine-to-machine (M2M) functionality---extending your business to new areas, driving efficiency, and reducing cost. The new Oracle Java ME Embedded product brings the benefits of Java technology to microcontroller platforms. It is a full-featured, complete, compliant software runtime with value-add features targeted to the embedded space and has the ability to interface with additional hardware components, remote manageability, and over-the-air software updates. It is accompanied by a feature-rich set of tools free of charge. (Fareed Suliman, Java Product Manager) "Embedded Java in Smart Energy and Healthcare" - This session covers embedded Java products and technologies that enable smart and connect devices in the Smart Energy and Healthcare/Medical industries. (speaker Kevin Lee) "Java SE Embedded Development on ARM Made Easy" - This Hands-on Lab aims to show that developers already familiar with the Java develop/debug/deploy lifecycle can apply those same skills to develop Java applications, using Java SE Embedded, on embedded devices. (speaker Jim Connors) In the Oracle booth #603, you can see the following demos: Industry Solutions with JavaThis exhibit consists of a number of industry solutions and how they can be powered by Java technology deployed on embedded systems.  Examples in consumer devices, home gateways, mobile health, smart energy, industrial control, and tablets all powered by applications running on the Java platform are shown.  Some of the solutions demonstrate the ability of Java to connect intelligent devices at the edge of the network to the datacenter or the cloud as a total end-to-end platform.Java in M2M with QualcommThis station will exhibit a new M2M solutions platform co-developed by Oracle and Qualcomm that enables wireless communications for embedded smart devices powered by Java, and share the types of industry solutions that are possible.  In addition, a new platform for wearable devices based on the ARM Cortex M3 platform is exhibited.Why Java for Embedded?Demonstration platforms will show how traditional development environments, tools, and Java programming skills can be used to create applications for embedded devices.  The advantages that Java provides because of  the runtime's abstraction of software from hardware, modularity and scalability, security, and application portability and manageability are shared with attendees. Drop by and see why Java is an optimal applications platform for embedded systems.

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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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• Perspective Is Everything

  - by juanlarios

  Sitting on a window seat on my way back from Seattle I looked out the window and saw the large body of water. I was reminded of childhood memories of running as hard as I could through burning hot sand with the anticipation of the splash of the ocean. Looking out the window the water appeared like a sheet draped over land. I couldn’t help but ponder how perspective changes everything.  Over the last several days I had a chance to attend the MVP Summit in Redmond. I had a great time with fellow MVP’s and the SharePoint Product Group. Although I can’t say much about what was discussed and what is coming in the future, I want to share some realizations I had while experiencing the MVP summit.  The SharePoint Product is ever-improving, full of innovation but also a reactionary embodiment of MVP, client and market feedback. There are several features that come to mind that clients complain about where I have felt helpless in informing them that the features are not as mature as they would like it. Together, we figure out a way to make it work and deal with the limitations. It became clear that there are features that have taken a different purpose in the market place from the original vision. The SP Product group is working hard to react to these changes in vision and make SharePoint better for real life implementations.  It is easy to think that SharePoint should be all things to all people. In reality there are products that are very detailed in specific composites, they do this one thing well but severely lack in other areas.  Its easy sometimes to say, “What was Microsoft thinking with this feature?” the Product group is doing all they can to make the moving pieces better and dealing with challenges with having all of them work together.  Sometimes the features don’t fully embody the vision because of the many challenges, but trust me when I say the product group is really focused on delivery and innovation.  As I was speaking with a fellow MVP throughout the session, we spoke about the iPad 2(ironically announced this past week during the MVP summit) and Microsoft’s possible product answer; I realized the days of reactionary products from MS is over. There are many users that will remember Vista and the painful execution in that product, but there has been a lot of success in Windows 7. There was no rush for a reactionary answer to the Nintendo Wii, as a result a ground breaking and game changing product was brought to market, the XBOX –Kinect! I can’t say much here, but it’s safe to say, expect innovation, and execution of products and technology that will change the market instead of react to them!       There are many things I learned and I would love to share that have to do with perspective, technology, etc… but this is far as I can go in details. This might not be new to you or specifically the message that was shared during the summit. These are just my impressions of the event and the spirit of future vision. Great things ahead!

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• What common interface would be appropriate for these game object classes?

  - by Jefffrey

  Question A component based system's goal is to solve the problems that derives from inheritance: for example the fact that some parts of the code (that are called components) are reused by very different classes that, hypothetically, would lie in a very different branch of the inheritance tree. That's a very nice concept, but I've found out that CBS is often hard to accomplish without using ugly hacks. Implementations of this system are often far from clean. But I don't want to discuss this any further. My question is: how can I solve the same problems a CBS try to solve with a very clean interface? (possibly with examples, there are a lot of abstract talks about the "perfect" design already). Context Here's an example I was going for before realizing I was just reinventing inheritance again: class Human { public: Position position; Movement movement; Sprite sprite; // other human specific components }; class Zombie { Position position; Movement movement; Sprite sprite; // other zombie specific components }; After writing that I realized I needed an interface, otherwise I would have needed N containers for N different types of objects (or to use boost::variant to gather them all together). So I've thought of polymorphism (move what systems do in a CBS design into class specific functions): class Entity { public: virtual void on_event(Event) {} // not pure virtual on purpose virtual void on_update(World) {} virtual void on_draw(Window) {} }; class Human : public Entity { private: Position position; Movement movement; Sprite sprite; public: virtual void on_event(Event) { ... } virtual void on_update(World) { ... } virtual void on_draw(Window) { ... } }; class Zombie : public Entity { private: Position position; Movement movement; Sprite sprite; public: virtual void on_event(Event) { ... } virtual void on_update(World) { ... } virtual void on_draw(Window) { ... } }; Which was nice, except for the fact that now the outside world would not even be able to know where a Human is positioned (it does not have access to its position member). That would be useful to track the player position for collision detection or if on_update the Zombie would want to track down its nearest human to move towards him. So I added const Position& get_position() const; to both the Zombie and Human classes. And then I realized that both functionality were shared, so it should have gone to the common base class: Entity. Do you notice anything? Yes, with that methodology I would have a god Entity class full of common functionality (which is the thing I was trying to avoid in the first place). Meaning of "hacks" in the implementation I'm referring to I'm talking about the implementations that defines Entities as simple IDs to which components are dynamically attached. Their implementation can vary from C-stylish: int last_id; Position* positions[MAX_ENTITIES]; Movement* movements[MAX_ENTITIES]; Where positions[i], movements[i], component[i], ... make up the entity. Or to more C++-style: int last_id; std::map<int, Position> positions; std::map<int, Movement> movements; From which systems can detect if an entity/id can have attached components.

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