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• Introducing Microsoft SQL Server 2008 R2 - Business Intelligence Samples

  - by smisner

  On April 14, 2010, Microsoft Press (blog | twitter) released my latest book, co-authored with Ross Mistry (twitter), as a free ebook download - Introducing Microsoft SQL Server 2008 R2. As the title implies, this ebook is an introduction to the latest SQL Server release. Although you'll find a comprehensive review of the product's features in this book, you will not find the step-by-step details that are typical in my other books. For those readers who are interested in a more interactive learning experience, I have created two samples file for download: IntroSQLServer2008R2Samples project Sales Analysis workbook Here's a recap of the business intelligence chapters and the samples I used to generate the screen shots by chapter: Chapter 6: Scalable Data Warehousing covers a new edition of SQL Server, Parallel Data Warehouse. Understandably, Microsoft did not ship me the software and hardware to set up my own Parallel Data Warehouse environment for testing purposes and consequently you won't see any screenshots in this chapter. I received a lot of information and a lot of help from the product team during the development of this chapter to ensure its technical accuracy. Chapter 7: Master Data Services is a new component in SQL Server. After you install Master Data Services (MDS), which is a separate installation from SQL Server although it's found on the same media, you can install sample models to explore (which is what I did to create screenshots for the book). To do this, you deploying packages found at \Program Files\Microsoft SQL Server\Master Data Services\Samples\Packages. You will first need to use the Configuration Manager (in the Microsoft SQL Server 2008 R2\Master Data Services program group) to create a database and a Web application for MDS. Then when you launch the application, you'll see a Getting Started page which has a Deploy Sample Data link that you can use to deploy any of the sample packages. Chapter 8: Complex Event Processing is an introduction to another new component, StreamInsight. This topic was way too large to cover in-depth in a single chapter, so I focused on information such as architecture, development models, and an overview of the key sections of code you'll need to develop for your own applications. StreamInsight is an engine that operates on data in-flight and as such has no user interface that I could include in the book as screenshots. The November CTP version of SQL Server 2008 R2 included code samples as part of the installation, but these are not the official samples that will eventually be available in Codeplex. At the time of this writing, the samples are not yet published. Chapter 9: Reporting Services Enhancements provides an overview of all the changes to Reporting Services in SQL Server 2008 R2, and there are many! In previous posts, I shared more details than you'll find in the book about new functions (Lookup, MultiLookup, and LookupSet), properties for page numbering, and the new global variable RenderFormat. I will confess that I didn't use actual data in the book for my discussion on the Lookup functions, but I did create real reports for the blog posts and will upload those separately. For the other screenshots and examples in the book, I have created the IntroSQLServer2008R2Samples project for you to download. To preview these reports in Business Intelligence Development Studio, you must have the AdventureWorksDW2008R2 database installed, and you must download and install SQL Server 2008 R2. For the map report, you must execute the PopulationData.sql script that I included in the samples file to add a table to the AdventureWorksDW2008R2 database. The IntroSQLServer2008R2Samples project includes the following files: 01_AggregateOfAggregates.rdl to illustrate the use of embedded aggregate functions 02_RenderFormatAndPaging.rdl to illustrate the use of page break properties (Disabled, ResetPageNumber), the PageName property, and the RenderFormat global variable 03_DataSynchronization.rdl to illustrate the use of the DomainScope property 04_TextboxOrientation.rdl to illustrate the use of the WritingMode property 05_DataBar.rdl 06_Sparklines.rdl 07_Indicators.rdl 08_Map.rdl to illustrate a simple analytical map that uses color to show population counts by state PopulationData.sql to provide the data necessary for the map report Chapter 10: Self-Service Analysis with PowerPivot introduces two new components to the Microsoft BI stack, PowerPivot for Excel and PowerPivot for SharePoint, which you can learn more about at the PowerPivot site. To produce the screenshots for this chapter, I created the Sales Analysis workbook which you can download (although you must have Excel 2010 and the PowerPivot for Excel add-in installed to explore it fully). It's a rather simple workbook because space in the book did not permit a complete exploration of all the wonderful things you can do with PowerPivot. I used a tutorial that was available with the CTP version as a basis for the report so it might look familiar if you've already started learning about PowerPivot. In future posts, I'll continue exploring the new features in greater detail. If there's any special requests, please let me know! Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• ASP.NET MVC 3 Hosting :: ASP.NET MVC 3 First Look

  - by mbridge

  MVC 3 View Enhancements MVC 3 introduces two improvements to the MVC view engine: - Ability to select the view engine to use. MVC 3 allows you to select from any of your  installed view engines from Visual Studio by selecting Add > View (including the newly introduced ASP.NET “Razor” engine”): - Support for the next ASP.NET “Razor” syntax. The newly previewed Razor syntax is a concise lightweight syntax. MVC 3 Control Enhancements - Global Filters: ASP.NET MVC 3  allows you to specify that a filter which applies globally to all Controllers within an app by adding it to the GlobalFilters collection.  The RegisterGlobalFilters() method is now included in the default Global.asax class template and so provides a convenient place to do this since is will then be called by the Application_Start() method: void RegisterGlobalFilters(GlobalFilterCollection filters) { filters.Add(new HandleLoggingAttribute()); filters.Add(new HandleErrorAttribute()); } void Application_Start() { RegisterGlobalFilters (GlobalFilters.Filters); } - Dynamic ViewModel Property : MVC 3 augments the ViewData API with a new “ViewModel” property on Controller which is of type “dynamic” – and therefore enables you to use the new dynamic language support in C# and VB pass ViewData items using a cleaner syntax than the current dictionary API. Public ActionResult Index() { ViewModel.Message = "Hello World"; return View(); } - New ActionResult Types : MVC 3 includes three new ActionResult types and helper methods: 1. HttpNotFoundResult – indicates that a resource which was requested by the current URL was not found. HttpNotFoundResult will return a 404 HTTP status code to the calling client. 2. PermanentRedirects – The HttpRedirectResult class contains a new Boolean “Permanent” property which is used to indicate that a permanent redirect should be done. Permanent redirects use a HTTP 301 status code.  The Controller class  includes three new methods for performing these permanent redirects: RedirectPermanent(), RedirectToRoutePermanent(), andRedirectToActionPermanent(). All  of these methods will return an instance of the HttpRedirectResult object with the Permanent property set to true. 3. HttpStatusCodeResult – used for setting an explicit response status code and its associated description. MVC 3 AJAX and JavaScript Enhancements MVC 3 ships with built-in JSON binding support which enables action methods to receive JSON-encoded data and then model-bind it to action method parameters. For example a jQuery client-side JavaScript could define a “save” event handler which will be invoked when the save button is clicked on the client. The code in the event handler then constructs a client-side JavaScript “product” object with 3 fields with their values retrieved from HTML input elements. Finally, it uses jQuery’s .ajax() method to POST a JSON based request which contains the product to a /theStore/UpdateProduct URL on the server: $('#save').click(function () { var product = { ProdName: $('#Name').val() Price: $('#Price').val(), } $.ajax({ url: '/theStore/UpdateProduct', type: "POST"; data: JSON.stringify(widget), datatype: "json", contentType: "application/json; charset=utf-8", success: function () { $('#message').html('Saved').fadeIn(), }, error: function () { $('#message').html('Error').fadeIn(), } }); return false; }); MVC will allow you to implement the /theStore/UpdateProduct URL on the server by using an action method as below. The UpdateProduct() action method will accept a strongly-typed Product object for a parameter. MVC 3 can now automatically bind an incoming JSON post value to the .NET Product type on the server without having to write any custom binding. [HttpPost] public ActionResult UpdateProduct(Product product) { // save logic here return null } MVC 3 Model Validation Enhancements MVC 3 builds on the MVC 2 model validation improvements by adding   support for several of the new validation features within the System.ComponentModel.DataAnnotations namespace in .NET 4.0: - Support for the new DataAnnotations metadata attributes like DisplayAttribute. - Support for the improvements made to the ValidationAttribute class which now supports a new IsValid overload that provides more info on  the current validation context, like what object is being validated. - Support for the new IValidatableObject interface which enables you to perform model-level validation and also provide validation error messages which are specific to the state of the overall model. MVC 3 Dependency Injection Enhancements MVC 3 includes better support for applying Dependency Injection (DI) and also integrating with Dependency Injection/IOC containers. Currently MVC 3 Preview 1 has support for DI in the below places: - Controllers (registering & injecting controller factories and injecting controllers) - Views (registering & injecting view engines, also for injecting dependencies into view pages) - Action Filters (locating and  injecting filters) And this is another important blog about Microsoft .NET and technology: - Windows 2008 Blog - SharePoint 2010 Blog - .NET 4 Blog And you can visit here if you're looking for ASP.NET MVC 3 hosting

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• PHP OCI8 and Oracle 11g DRCP Connection Pooling in Pictures

  - by christopher.jones

  Here is a screen shot from a PHP OCI8 connection pooling demo that I like to run. It graphically shows how little database host memory is needed when using DRCP connection pooling with Oracle Database 11g. Migrating to DRCP can be as simple as starting the pool and changing the connection string in your PHP application. The script that generated the data for this graph was a simple "Parts" query application being run under various simulated user loads. I was running the database on a small Oracle Linux server with just 2G of memory. I used PHP OCI8 1.4. Apache is in pre-fork mode, as needed for PHP. Each graph has time on the horizontal access in arbitrary 'tick' time units. Click the image to see it full sized. Pooled connections Beginning with the top left graph, At tick time 65 I used Apache's 'ab' tool to start 100 concurrent 'users' running the application. These users connected to the database using DRCP: $c = oci_pconnect('phpdemo', 'welcome', 'myhost/orcl:pooled'); A second hundred DRCP users were added to the system at tick 80 and a final hundred users added at tick 100. At about tick 110 I stopped the test and restarted Apache. This closed all the connections. The bottom left graph shows the number of statements being executed by the database per second, with some spikes for background database activity and some variability for this small test. Each extra batch of users adds another 'step' of load to the system. Looking at the top right Server Process graph shows the database server processes doing the query work for each web user. As user load is added, the DRCP server pool increases (in green). The pool is initially at its default size 4 and quickly ramps up to about (I'm guessing) 35. At tick time 100 the pool increases to my configured maximum of 40 processes. Those 40 processes are doing the query work for all 300 web users. When I stopped the test at tick 110, the pooled processes remained open waiting for more users to connect. If I had left the test quiet for the DRCP 'inactivity_timeout' period (300 seconds by default), the pool would have shrunk back to 4 processes. Looking at the bottom right, you can see the amount of memory being consumed by the database. During the initial quiet period about 500M of memory was in use. The absolute number is just an indication of my particular DB configuration. As the number of pooled processes increases, each process needs more memory. You can see the shape of the memory graph echoes the Server Process graph above it. Each of the 300 web users will also need a few kilobytes but this is almost too small to see on the graph. Non-pooled connections Compare the DRCP case with using 'dedicated server' processes. At tick 140 I started 100 web users who did not use pooled connections: $c = oci_pconnect('phpdemo', 'welcome', 'myhost/orcl'); This connection string change is the only difference between the two tests. At ticks 155 and 165 I started two more batches of 100 simulated users each. At about tick 195 I stopped the user load but left Apache running. Apache then gradually returned to its quiescent state, killing idle httpd processes and producing the downward slope at the right of the graphs as the persistent database connection in each Apache process was closed. The Executions per Second graph on the bottom left shows the same step increases as for the earlier DRCP case. The database is handling this load. But look at the number of Server processes on the top right graph. There is now a one-to-one correspondence between Apache/PHP processes and DB server processes. Each PHP processes has one DB server processes dedicated to it. Hence the term 'dedicated server'. The memory required on the database is proportional to all those database server processes started. Almost all my system's memory was consumed. I doubt it would have coped with any more user load. Summary Oracle Database 11g DRCP connection pooling significantly reduces database host memory requirements allow more system memory to be allocated for the SGA and allowing the system to scale to handled thousands of concurrent PHP users. Even for small systems, using DRCP allows more web users to be active. More information about PHP and DRCP can be found in the PHP Scalability and High Availability chapter of The Underground PHP and Oracle Manual.

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• Oracle Database 12c: Oracle Multitenant Option

  - by hamsun

  1. Why ? 2. What is it ? 3. How ? 1. Why ? The main idea of the 'grid' is to share resources, to make better use of storage, CPU and memory. If a database administrator wishes to implement this idea, he or she must consolidate many databases to one database. One of the concerns of running many applications together in one database is: ‚what will happen, if one of the applications must be restored because of a human error?‘ Tablespace point in time recovery can be used for this purpose, but there are a few prerequisites. Most importantly the tablespaces are strictly separated for each application. Another reason for creating separated databases is security: each customer has his own database. Therefore, there is often a proliferation of smaller databases. Each of them must be maintained, upgraded, each allocates virtual memory and runs background processes thereby wasting resources. Oracle 12c offers another possibility for virtualization, providing isolation at the database level: the multitenant container database holding pluggable databases. 2. What ? Pluggable databases are logical units inside a multitenant container database, which consists of one multitenant container database and up to 252 pluggable databases. The SGA is shared as are the background processes. The multitenant container database holds metadata information common for pluggable databases inside the System and the Sysaux tablespace, and there is just one Undo tablespace. The pluggable databases have smaller System and Sysaux tablespaces, containing just their 'personal' metadata. New data dictionary views will make the information available either on pdb (dba_views) or container level (cdb_views). There are local users, which are known in specific pluggable databases and common users known in all containers. Pluggable databases can be easily plugged to another multitenant container database and converted from a non-CDB. They can undergo point in time recovery. 3. How ? Creating a multitenant container database can be done using the database configuration assistant: There you find the new option: Create as Container Database. If you prefer ‚hand made‘ databases you can execute the command from a instance in nomount state: CREATE DATABASE cdb1 ENABLE PLUGGABLE DATABASE …. And of course this can also be achieved through Enterprise Manager Cloud. A freshly created multitenant container database consists of two containers: the root container as the 'rack' and a seed container, a template for future pluggable databases. There are 4 ways to create other pluggable databases: 1. Create an empty pdb from seed 2. Plug in a non-CDB 3. Move a pdb from another pdb 4. Copy a pdb from another pdb We will discuss option2: how to plug in a non_CDB into a multitenant container database. Three different methods are available : 1. Create an empty pdb and use Datapump in traditional export/import mode or with Transportable Tablespace or Database mode. This method is suitable for pre 12c databases. 2. Create an empty pdb and use GoldenGate replication. When the pdb catches up with the non-CDB, you fail over to the pdb. 3. Databases of Version 12c or higher can be plugged in with the help of the new dbms_pdb Package. This is a demonstration for method 3: Step1: Connect to the non-CDB to be plugged in and create an xml File with description of the database. The xml file is written to $ORACLE_HOME/dbs per default and contains mainly information about the datafiles. Step 2: Check if the non-CDB is pluggable in the multitenant container database: Step 3: Create the pluggable database, connected to the Multitenant container database. With nocopy option the files will be reused, but the tempfile is created anew: A service is created and registered automatically with the listener: Step 4: Delete unnecessary metadata from PDB SYSTEM tablespace: To connect to newly created pdb, edit tnsnames.ora and add entry for new pdb. Connect to plugged-in non_CDB and clean up Data Dictionary to remove entries now maintained in multitenant container database. As all kept objects have to be recompiled it will take a few minutes. Step 5: The plugged-in database will be automatically synchronised by creating common users and roles when opened the first time in read write mode. Step 6: Verify tablespaces and users: There is only one local tablespace (users) and one local user (scott) in the plugged-in non_CDB pdb_orcl. This method of creating plugged_in non_CDB from is fast and easy for 12c databases. The method for deplugging a pluggable database from a CDB is to create a new non_CDB and use the the new full transportable feature of Datapump and drop the pluggable database. About the Author: Gerlinde has been working for Oracle University Germany as one of our Principal Instructors for over 14 years. She started with Oracle 7 and became an Oracle Certified Master for Oracle 10g and 11c. She is a specialist in Database Core Technologies, with profound knowledge in Backup & Recovery, Performance Tuning for DBAs and Application Developers, Datawarehouse Administration, Data Guard and Real Application Clusters.

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• My History with Agile

  - by Robert May

  I’m going to write my history with Agile here.  That way, in future posts, I can refer back to it, instead of typing it out in the post that contains information you may actually want to read.  Note that I’m actually a pretty senior developer, and do lots of technical interviews.  I’m an Agile fan because of the difference it makes in peoples lives and the improvement in quality it brings, and I’ll sacrifice my technological advance to help teams. Management History I started management pretty early in my career, starting with the first job that I ever had.  I actually do NOT have a CS or similar degree.  I have a Bachelor’s of Business Administration with an emphasis in Computer Information Systems. My first management gigs were around call center work and were very schedule oriented.  I didn’t understand the true value of teams, and I’m ashamed to admit, I actually installed a fingerprint scanner as a time clock in this job.  I shudder to think of the impact that I had on the team spirit.  I didn’t even trust them enough to fill out their time cards correctly.  How sad. I was managing nearly 100 people in this position, with the help of a great set of subordinates. I did try to come up with reward programs for the team, but again, didn’t understand the concept of team, so instead of letting the team determine how the rewards should work, I mandated from on high, which isn’t a good thing. I was told that I wasn’t the type that would be a good manager by people whom I respected a lot.  They said it because I was a computer geek, since they don’t understand good management either, but in retrospect, they were right about me then.  I was too green. After my first job, I went on to other jobs and with the exception of one job, I’ve managed people at them all.  The rest of the management story is important for understanding agile, so I’ll save it for my next post. Technical History I’ve been in software development for many, many years.  I technically started programming on a commodore 64 in basic.  I didn’t know that I was programming, but I was sure having fun.  That was followed by batch files, Gorilla hacking (I always had to win), WordPerfect Macro programming and other things that taught me the basics. My first “real” job was with a telephone company, and that’s where I made my first database application in DataEase, wrote my first VBA app and started using real programming tools, like turbo pascal, vb3-vb5, and semi-real tools like RPG and VisualRPG.  I wrote my first web page in 1994, and built my first data driven web page in 1995 using perlDB.  You really can do anything with Perl.  At this time, I also started a Linux based internet service provider that is still in operation today.  One of the people I worked with is now a Microsoft employee building and designing frameworks you probably know well.  Smart guy.  I also built my first ASP applications connecting to Sql Server 6.5, setup Exchange 5.5 for the company, and many other system administration stuff.  I’m a programmer by choice, mostly because I don’t really like PC support. From there, I went on to a large state agency.  I got to see and maintain true waterfall projects.  5 years of maintaining the 200 VB COM+ (MTS, actually) dlls that were used to calculate a single number is a long time.  That was all Microsoft DNS technologies.  SQL Server and VB6 were the tools of choice, although .net started to be a factor near the end of employment.  I did some heavy XML work at this job and even wrote an XSD parser and validator in VB6 that was a shim until MSXML 3.0 came out.  Prior to 3.0, XSD’s weren’t supported, and I didn’t want to write DTDs. Ironically, jobs after this were more generic.  I pretty much settled in on the .net framework and revisions of it.  Lots of WPF, some silverlight, lots of ASP.NET, some SQL Azure, lots of SQL Server, some Oracle, but I don’t think that I was as passionate about development and technologies.  I was more into the management of development.  I like people. Technorati Tags: Agile,history

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• World Record Oracle Business Intelligence Benchmark on SPARC T4-4

  - by Brian

  Oracle's SPARC T4-4 server configured with four SPARC T4 3.0 GHz processors delivered the first and best performance of 25,000 concurrent users on Oracle Business Intelligence Enterprise Edition (BI EE) 11g benchmark using Oracle Database 11g Release 2 running on Oracle Solaris 10. A SPARC T4-4 server running Oracle Business Intelligence Enterprise Edition 11g achieved 25,000 concurrent users with an average response time of 0.36 seconds with Oracle BI server cache set to ON. The benchmark data clearly shows that the underlying hardware, SPARC T4 server, and the Oracle BI EE 11g (11.1.1.6.0 64-bit) platform scales within a single system supporting 25,000 concurrent users while executing 415 transactions/sec. The benchmark demonstrated the scalability of Oracle Business Intelligence Enterprise Edition 11g 11.1.1.6.0, which was deployed in a vertical scale-out fashion on a single SPARC T4-4 server. Oracle Internet Directory configured on SPARC T4 server provided authentication for the 25,000 Oracle BI EE users with sub-second response time. A SPARC T4-4 with internal Solid State Drive (SSD) using the ZFS file system showed significant I/O performance improvement over traditional disk for the Web Catalog activity. In addition, ZFS helped get past the UFS limitation of 32767 sub-directories in a Web Catalog directory. The multi-threaded 64-bit Oracle Business Intelligence Enterprise Edition 11g and SPARC T4-4 server proved to be a successful combination by providing sub-second response times for the end user transactions, consuming only half of the available CPU resources at 25,000 concurrent users, leaving plenty of head room for increased load. The Oracle Business Intelligence on SPARC T4-4 server benchmark results demonstrate that comprehensive BI functionality built on a unified infrastructure with a unified business model yields best-in-class scalability, reliability and performance. Oracle BI EE 11g is a newer version of Business Intelligence Suite with richer and superior functionality. Results produced with Oracle BI EE 11g benchmark are not comparable to results with Oracle BI EE 10g benchmark. Oracle BI EE 11g is a more difficult benchmark to run, exercising more features of Oracle BI. Performance Landscape Results for the Oracle BI EE 11g version of the benchmark. Results are not comparable to the Oracle BI EE 10g version of the benchmark. Oracle BI EE 11g Benchmark System Number of Users Response Time (sec) 1 x SPARC T4-4 (4 x SPARC T4 3.0 GHz) 25,000 0.36 Results for the Oracle BI EE 10g version of the benchmark. Results are not comparable to the Oracle BI EE 11g version of the benchmark. Oracle BI EE 10g Benchmark System Number of Users 2 x SPARC T5440 (4 x SPARC T2+ 1.6 GHz) 50,000 1 x SPARC T5440 (4 x SPARC T2+ 1.6 GHz) 28,000 Configuration Summary Hardware Configuration: SPARC T4-4 server 4 x SPARC T4-4 processors, 3.0 GHz 128 GB memory 4 x 300 GB internal SSD Storage Configuration: "> Sun ZFS Storage 7120 16 x 146 GB disks Software Configuration: Oracle Solaris 10 8/11 Oracle Solaris Studio 12.1 Oracle Business Intelligence Enterprise Edition 11g (11.1.1.6.0) Oracle WebLogic Server 10.3.5 Oracle Internet Directory 11.1.1.6.0 Oracle Database 11g Release 2 Benchmark Description Oracle Business Intelligence Enterprise Edition (Oracle BI EE) delivers a robust set of reporting, ad-hoc query and analysis, OLAP, dashboard, and scorecard functionality with a rich end-user experience that includes visualization, collaboration, and more. The Oracle BI EE benchmark test used five different business user roles - Marketing Executive, Sales Representative, Sales Manager, Sales Vice-President, and Service Manager. These roles included a maximum of 5 different pre-built dashboards. Each dashboard page had an average of 5 reports in the form of a mix of charts, tables and pivot tables, returning anywhere from 50 rows to approximately 500 rows of aggregated data. The test scenario also included drill-down into multiple levels from a table or chart within a dashboard. The benchmark test scenario uses a typical business user sequence of dashboard navigation, report viewing, and drill down. For example, a Service Manager logs into the system and navigates to his own set of dashboards using Service Manager. The BI user selects the Service Effectiveness dashboard, which shows him four distinct reports, Service Request Trend, First Time Fix Rate, Activity Problem Areas, and Cost Per Completed Service Call spanning 2002 to 2005. The user then proceeds to view the Customer Satisfaction dashboard, which also contains a set of 4 related reports, drills down on some of the reports to see the detail data. The BI user continues to view more dashboards – Customer Satisfaction and Service Request Overview, for example. After navigating through those dashboards, the user logs out of the application. The benchmark test is executed against a full production version of the Oracle Business Intelligence 11g Applications with a fully populated underlying database schema. The business processes in the test scenario closely represent a real world customer scenario. See Also SPARC T4-4 Server oracle.com OTN Oracle Business Intelligence oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN WebLogic Suite oracle.com OTN Oracle Solaris oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 30 September 2012.

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• Kernel, dpkg, sudo and apt-get corrupted

  - by TECH4JESUS

  Here are some errors that I am getting: 1) A proper configuration for Firestarter was not found. If you are running Firestarter from the directory you built it in, run make install-data-local to install a configuration, or simply make install to install the whole program. Firestarter will now close. root@p:/# firestarter ** (firestarter:5890): WARNING **: The connection is closed (firestarter:5890): GnomeUI-WARNING **: While connecting to session manager: None of the authentication protocols specified are supported. (firestarter:5890): GConf-WARNING **: Client failed to connect to the D-BUS daemon: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. (firestarter:5890): GConf-WARNING **: Client failed to connect to the D-BUS daemon: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. (firestarter:5890): GConf-WARNING **: Client failed to connect to the D-BUS daemon: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. (firestarter:5890): GConf-WARNING **: Client failed to connect to the D-BUS daemon: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. (firestarter:5890): GConf-WARNING **: Client failed to connect to the D-BUS daemon: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. (firestarter:5890): GConf-WARNING **: Client failed to connect to the D-BUS daemon: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. (firestarter:5890): GConf-WARNING **: Client failed to connect to the D-BUS daemon: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. ^C 2) Also I cannot apt-get install sudo root@p:/# apt-get install sudo Reading package lists... Done Building dependency tree Reading state information... Done sudo is already the newest version. The following packages were automatically installed and are no longer required: gir1.2-rb-3.0 gir1.2-gstreamer-0.10 libntfs10 python-mako libdmapsharing-3.0-2 rhythmbox-data libx264-116 rhythmbox libiso9660-7 librhythmbox-core5 libvpx0 libmatroska4 gir1.2-gst-plugins-base-0.10 rhythmbox-mozilla rhythmbox-plugin-zeitgeist libattica0 libgpac0.4.5 python-markupsafe libmusicbrainz4c2a rhythmbox-plugin-cdrecorder rhythmbox-plugins libaudiofile0 Use 'apt-get autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 18 not upgraded. 9 not fully installed or removed. Need to get 0 B/76.3 MB of archives. After this operation, 0 B of additional disk space will be used. Do you want to continue [Y/n]? Y /bin/sh: 1: /usr/sbin/dpkg-preconfigure: not found (Reading database ... 495741 files and directories currently installed.) Preparing to replace linux-image-3.2.0-24-generic 3.2.0-24.39 (using .../linux-image-3.2.0-24-generic_3.2.0-24.39_amd64.deb) ... dpkg (subprocess): unable to execute old pre-removal script (/var/lib/dpkg/info/linux-image-3.2.0-24-generic.prerm): No such file or directory dpkg: warning: subprocess old pre-removal script returned error exit status 2 dpkg - trying script from the new package instead ... dpkg (subprocess): unable to execute new pre-removal script (/var/lib/dpkg/tmp.ci/prerm): No such file or directory dpkg: error processing /var/cache/apt/archives/linux-image-3.2.0-24-generic_3.2.0-24.39_amd64.deb (--unpack): subprocess new pre-removal script returned error exit status 2 dpkg (subprocess): unable to execute installed post-installation script (/var/lib/dpkg/info/linux-image-3.2.0-24-generic.postinst): No such file or directory dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 2 Preparing to replace linux-image-3.2.0-25-generic 3.2.0-25.40 (using .../linux-image-3.2.0-25-generic_3.2.0-25.40_amd64.deb) ... dpkg (subprocess): unable to execute old pre-removal script (/var/lib/dpkg/info/linux-image-3.2.0-25-generic.prerm): No such file or directory dpkg: warning: subprocess old pre-removal script returned error exit status 2 dpkg - trying script from the new package instead ... dpkg (subprocess): unable to execute new pre-removal script (/var/lib/dpkg/tmp.ci/prerm): No such file or directory dpkg: error processing /var/cache/apt/archives/linux-image-3.2.0-25-generic_3.2.0-25.40_amd64.deb (--unpack): subprocess new pre-removal script returned error exit status 2 dpkg (subprocess): unable to execute installed post-installation script (/var/lib/dpkg/info/linux-image-3.2.0-25-generic.postinst): No such file or directory dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 2 Errors were encountered while processing: /var/cache/apt/archives/linux-image-3.2.0-24-generic_3.2.0-24.39_amd64.deb /var/cache/apt/archives/linux-image-3.2.0-25-generic_3.2.0-25.40_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)

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• Partition Wise Joins

  - by jean-pierre.dijcks

  Some say they are the holy grail of parallel computing and PWJ is the basis for a shared nothing system and the only join method that is available on a shared nothing system (yes this is oversimplified!). The magic in Oracle is of course that is one of many ways to join data. And yes, this is the old flexibility vs. simplicity discussion all over, so I won't go there... the point is that what you must do in a shared nothing system, you can do in Oracle with the same speed and methods. The Theory A partition wise join is a join between (for simplicity) two tables that are partitioned on the same column with the same partitioning scheme. In shared nothing this is effectively hard partitioning locating data on a specific node / storage combo. In Oracle is is logical partitioning. If you now join the two tables on that partitioned column you can break up the join in smaller joins exactly along the partitions in the data. Since they are partitioned (grouped) into the same buckets, all values required to do the join live in the equivalent bucket on either sides. No need to talk to anyone else, no need to redistribute data to anyone else... in short, the optimal join method for parallel processing of two large data sets. PWJ's in Oracle Since we do not hard partition the data across nodes in Oracle we use the Partitioning option to the database to create the buckets, then set the Degree of Parallelism (or run Auto DOP - see here) and get our PWJs. The main questions always asked are: How many partitions should I create? What should my DOP be? In a shared nothing system the answer is of course, as many partitions as there are nodes which will be your DOP. In Oracle we do want you to look at the workload and concurrency, and once you know that to understand the following rules of thumb. Within Oracle we have more ways of joining of data, so it is important to understand some of the PWJ ideas and what it means if you have an uneven distribution across processes. Assume we have a simple scenario where we partition the data on a hash key resulting in 4 hash partitions (H1 -H4). We have 2 parallel processes that have been tasked with reading these partitions (P1 - P2). The work is evenly divided assuming the partitions are the same size and we can scan this in time t1 as shown below. Now assume that we have changed the system and have a 5th partition but still have our 2 workers P1 and P2. The time it takes is actually 50% more assuming the 5th partition has the same size as the original H1 - H4 partitions. In other words to scan these 5 partitions, the time t2 it takes is not 1/5th more expensive, it is a lot more expensive and some other join plans may now start to look exciting to the optimizer. Just to post the disclaimer, it is not as simple as I state it here, but you get the idea on how much more expensive this plan may now look... Based on this little example there are a few rules of thumb to follow to get the partition wise joins. First, choose a DOP that is a factor of two (2). So always choose something like 2, 4, 8, 16, 32 and so on... Second, choose a number of partitions that is larger or equal to 2* DOP. Third, make sure the number of partitions is divisible through 2 without orphans. This is also known as an even number... Fourth, choose a stable partition count strategy, which is typically hash, which can be a sub partitioning strategy rather than the main strategy (range - hash is a popular one). Fifth, make sure you do this on the join key between the two large tables you want to join (and this should be the obvious one...). Translating this into an example: DOP = 8 (determined based on concurrency or by using Auto DOP with a cap due to concurrency) says that the number of partitions >= 16. Number of hash (sub) partitions = 32, which gives each process four partitions to work on. This number is somewhat arbitrary and depends on your data and system. In this case my main reasoning is that if you get more room on the box you can easily move the DOP for the query to 16 without repartitioning... and of course it makes for no leftovers on the table... And yes, we recommend up-to-date statistics. And before you start complaining, do read this post on a cool way to do stats in 11.

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• Connection Pooling is Busted

  - by MightyZot

  A few weeks ago we started getting complaints about performance in an application that has performed very well for many years.  The application is a n-tier application that uses ADODB with the SQLOLEDB provider to talk to a SQL Server database.  Our object model is written in such a way that each public method validates security before performing requested actions, so there is a significant number of queries executed to get information about file cabinets, retrieve images, create workflows, etc.  (PaperWise is a document management and workflow system.)  A common factor for these customers is that they have remote offices connected via MPLS networks. Naturally, the first thing we looked at was the query performance in SQL Profiler.  All of the queries were executing within expected timeframes, most of them were so fast that the duration in SQL Profiler was zero.  After getting nowhere with SQL Profiler, the situation was escalated to me.  I decided to take a peek with Process Monitor.  Procmon revealed some “gaps” in the TCP/IP traffic.  There were notable delays between send and receive pairs.  The send and receive pairs themselves were quite snappy, but quite often there was a notable delay between a receive and the next send.  You might expect some delay because, presumably, the application is doing some thinking in-between the pairs.  But, comparing the procmon data at the remote locations with the procmon data for workstations on the local network showed that the remote workstations were significantly delayed.  Procmon also showed a high number of disconnects. Wireshark traces showed that connections to the database were taking between 75ms and 150ms.  Not only that, but connections to a file share containing images were taking 2 seconds!  So, I asked about a trust.  Sure enough there was a trust between two domains and the file share was on the second domain.  Joining a remote workstation to the domain hosting the share containing images alleviated the time delay in accessing the file share.  Removing the trust had no affect on the connections to the database. Microsoft Network Monitor includes filters that parse TDS packets.  TDS is the protocol that SQL Server uses to communicate.  There is a certificate exchange and some SSL that occurs during authentication.  All of this was evident in the network traffic.  After staring at the network traffic for a while, and examining packets, I decided to call it a night.  On the way home that night, something about the traffic kept nagging at me.  Then it dawned on me…at the beginning of the dance of packets between the client and the server all was well.  Connection pooling was working and I could see multiple queries getting executed on the same connection and ethereal port.  After a particular query, connecting to two different servers, I noticed that ADODB and SQLOLEDB started making repeated connections to the database on different ethereal ports.  SQL Server would execute a single query and respond on a port, then open a new port and execute the next query.  Connection pooling appeared to be broken. The next morning I wrote a test to confirm my hypothesis.  Turns out that the sequence causing the connection nastiness goes something like this: Make a connection to the database. Open a result set that returns enough records to require multiple roundtrips to the server. For each result, query for some other data in the database (this will open a new implicit connection.) Close the inner result set and repeat for every item in the original result set. Close the original connection. Provided that the first result set returns enough data to require multiple roundtrips to the server, ADODB and SQLOLEDB will start making new connections to the database for each query executed in the loop.  Originally, I thought this might be due to Microsoft’s denial of service (ddos) attack protection.  After turning those features off to no avail, I eventually thought to switch my queries to client-side cursors instead of server-side cursors.  Server-side cursors are the default, by the way.  Voila!  After switching to client-side cursors, the disconnects were gone and the above sequence yielded two connections as expected. While the real problem is the amount of time it takes to make connections over these MPLS networks (100ms on average), switching to client-side cursors made the problem go away.  Believe it or not, this is actually documented by Microsoft, and rather difficult to find.  (At least it was while we were trying to troubleshoot the problem!)  So, if you’re noticing performance issues on slower networks, or networks with slower switching, take a look at the traffic in a tool like Microsoft Network Monitor.  If you notice a high number of disconnects, and you’re using fire-hose or server-side cursors, then try switching to client-side cursors and you may see the problem go away. Most likely, Microsoft believes this to be appropriate behavior, because ADODB can’t guarantee that all of the data has been retrieved when you execute the inner queries.  I’m not convinced, though, because the problem remains even after replacing all of the implicit connections with explicit connections and closing those connections in-between each of the inner queries.  In that case, there doesn’t seem to be a reason why ADODB can’t use a single connection from the connection pool to make the additional queries, bringing the total number of connections to two.  Instead ADO appears to make an assumption about the state of the connection. I’ve reported the behavior to Microsoft and am awaiting to hear from the appropriate team, so that I can demonstrate the problem.  Maybe they can explain to us why this is appropriate behavior.  :)

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• SQL SERVER – Weekly Series – Memory Lane – #005

  - by pinaldave

  Here is the list of curetted articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2006 SQL SERVER – Cursor to Kill All Process in Database I indeed wrote this cursor and when I often look back, I wonder how naive I was to write this. The reason for writing this cursor was to free up my database from any existing connection so I can do database operation. This worked fine but there can be a potentially big issue if there was any important transaction was killed by this process. There is another way to to achieve the same thing where we can use ALTER syntax to take database in single user mode. Read more about that over here and here. 2007 Rules of Third Normal Form and Normalization Advantage – 3NF The rules of 3NF are mentioned here Make a separate table for each set of related attributes, and give each table a primary key. If an attribute depends on only part of a multi-valued key, remove it to a separate table If attributes do not contribute to a description of the key, remove them to a separate table. Correct Syntax for Stored Procedure SP Sometime a simple question is the most important question. I often see in industry incorrectly written Stored Procedure. Few writes code after the most outer BEGIN…END and few writes code after the GO Statement. In this brief blog post, I have attempted to explain the same. 2008 Switch Between Result Pan and Query Pan – SQL Shortcut Many times when I am writing query I have to scroll the result displayed in the result set. Most of the developer uses the mouse to switch between and Query Pane and Result Pane. There are few developers who are crazy about Keyboard shortcuts. F6 is the keyword which can be used to switch between query pane and tabs of the result pane. Interesting Observation – Use of Index and Execution Plan Query Optimization is a complex game and it has its own rules. From the example in the article we have discovered that Query Optimizer does not use clustered index to retrieve data, sometime non clustered index provides optimal performance for retrieving Primary Key. When all the rows and columns are selected Primary Key should be used to select data as it provides optimal performance. 2009 Interesting Observation – TOP 100 PERCENT and ORDER BY If you pull up any application or system where there are more than 100 SQL Server Views are created – I am very confident that at one or two places you will notice the scenario wherein View the ORDER BY clause is used with TOP 100 PERCENT. SQL Server 2008 VIEW with ORDER BY clause does not throw an error; moreover, it does not acknowledge the presence of it as well. In this article we have taken three perfect examples and demonstrated which clause we should use when. Comma Separated Values (CSV) from Table Column A Very common question – How to create comma separated values from a table in the database? The answer is also very common if we use XML. Check out this article for quick learning on the same subject. Azure Start Guide – Step by Step Installation Guide Though Azure portal has changed a quite bit since I wrote this article, the concept used in this article are not old. They are still valid and many of the functions are still working as mentioned in the article. I believe this one article will put you on the track to use Azure! Size of Index Table for Each Index – Solution Earlier I have posted a small question on this blog and requested help from readers to participate here and provide a solution. The puzzle was to write a query that will return the size for each index that is on any particular table. We need a query that will return an additional column in the above listed query and it should contain the size of the index. This article presents two of the best solutions from the puzzle. 2010 Well, this week in 2010 was the week of puzzles as I posted three interesting puzzles. Till today I am noticing pretty good interesting in the puzzles. They are tricky but for sure brings a great value if you are a database developer for a long time. I suggest you go over this puzzles and their answers. Did you really know all of the answers? I am confident that reading following three blog post will for sure help you enhance the experience with T-SQL. SQL SERVER – Challenge – Puzzle – Usage of FAST Hint SQL SERVER – Puzzle – Challenge – Error While Converting Money to Decimal SQL SERVER – Challenge – Puzzle – Why does RIGHT JOIN Exists 2011 DVM sys.dm_os_sys_info Column Name Changed in SQL Server 2012 Have you ever faced a situation where something does not work? When you try to fix it - you enjoy fixing it and started to appreciate the breaking changes. Well, this was exactly I felt yesterday. Before I begin my story, I want to candidly state that I do not encourage anybody to use * in the SELECT statement. Now the disclaimer is over – I suggest you read the original story – you will love it! Get Directory Structure using Extended Stored Procedure xp_dirtree Here is the question to you – why would you do something in SQL Server where you can do the same task in command prompt much easily. Well, the answer is sometime there are real use cases when we have to do such thing. This is a similar example where I have demonstrated how in SQL Server 2012 we can use extended stored procedure to retrieve directory structure. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Migrating SQL Server Databases – The DBA’s Checklist (Part 2)

  - by Sadequl Hussain

  Continuing from Part 1  , our Migration Checklist continues: Step 5: Update statistics It is always a good idea to update the statistics of the database that you have just installed or migrated. To do this, run the following command against the target database: sp_updatestats The sp_updatestats system stored procedure runs the UPDATE STATISTICS command against every user and system table in the database.  However, a word of caution: running the sp_updatestats against a database with a compatibility level below 90 (SQL Server 2005) will reset the automatic UPDATE STATISTICS settings for every index and statistics of every table in the database. You may therefore want to change the compatibility mode before you run the command. Another thing you should remember to do is to ensure the new database has its AUTO_CREATE_STATISTICS and AUTO_UPDATE_STATISTICS properties set to ON. You can do so using the ALTER DATABASE command or from the SSMS. Step 6: Set database options You may have to change the state of a database after it has been restored. If the database was changed to single-user or read-only mode before backup, the restored copy will also retain these settings. This may not be an issue when you are manually restoring from Enterprise Manager or the Management Studio since you can change the properties. However, this is something to be mindful of if the restore process is invoked by an automated job or script and the database needs to be written to immediately after restore. You may want to check the database’s status programmatically in such cases. Another important option you may want to set for the newly restored / attached database is PAGE_VERIFY. This option specifies how you want SQL Server to ensure the physical integrity of the data. It is a new option from SQL Server 2005 and can have three values: CHECKSUM (default for SQL Server 2005 and latter databases), TORN_PAGE_DETECTION (default when restoring a pre-SQL Server 2005 database) or NONE. Torn page detection was itself an option for SQL Server 2000 databases. From SQL Server 2005, when PAGE_VERIFY is set to CHECKSUM, the database engine calculates the checksum for a page’s contents and writes it to the page header before storing it in disk. When the page is read from the disk, the checksum is computed again and compared with the checksum stored in the header.  Torn page detection works much like the same way in that it stores a bit in the page header for every 512 byte sector. When data is read from the page, the torn page bits stored in the header is compared with the respective sector contents. When PAGE_VERIFY is set to NONE, SQL Server does not perform any checking, even if torn page data or checksums are present in the page header.  This may not be something you would want to set unless there is a very specific reason.  Microsoft suggests using the CHECKSUM page verify option as this offers more protection. Step 7: Map database users to logins A common database migration issue is related to user access. Windows and SQL Server native logins that existed in the source instance and had access to the database may not be present in the destination. Even if the logins exist in the destination, the mapping between the user accounts and the logins will not be automatic. You can use a special system stored procedure called sp_change_users_login to address these situations. The procedure needs to be run against the newly attached or restored database and can accept four parameters. Depending on what you want to do, you may be using less than four though. The first parameter, @Action, can take three values. When you specify @Action = ‘Report’, the system will provide you with a list of database users which are not mapped to any login. If you want to map a database user to an existing SQL Server login, the value for @Action will be ‘Update_One’. In this case, you will only need to provide the database user name and the login it will map to. So if your newly restored database has a user account called “bob” and there is already a SQL Server login with the same name and you want to map the user to the login, you will execute a query like the following: sp_change_users_login         @Action = ‘Update_One’,         @UserNamePattern = ‘bob’,         @LoginName = ‘bob’ If the login does not exist, you can instruct SQL Server to create the login with the same name. In this case you will need to provide a password for the login and the value of the @Action parameter will be ‘Auto_Fix’. If the login already exists, it will be automatically mapped to the user account. Unfortunately sp_change_users_login system stored procedure cannot be used to map database users to trusted logins (Windows accounts) in SQL Server. You will need to follow a manual process to re-map the database user accounts.  Continues…

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• CQRS - Benefits

  - by Dylan Smith

  Thanks to all the comments and feedback from the last post I think I have a better understanding now of the benefits of CQRS (separate from the benefits of Event Sourcing). I’m going to try and sum it up here, and point out some areas where I could still use some advice: CQRS Benefits Sounds like the primary benefit of CQRS as an architecture is it allows you to create a simpler domain model by sucking out everything related to queries. I can definitely see the benefit to this, in general the domain logic related to commands is the high-value behavior in the software, but the logic required to service the queries would add a lot of low-value “noise” to the domain model that would dilute the high-value (command) behavior – sorting, paging, filtering, pre-fetch paths, etc. Also the most appropriate domain structure for implementing commands might not be the most optimal for implementing queries. To paraphrase Greg, this usually results in a domain model that is mediocre at both, piss-poor at one, or more likely piss-poor at both commands and queries. Not only will you be able to simplify your domain model by pulling out all the query logic, but at least a handful of commands in most systems will probably be “pass-though” type commands with little to no logic that just generate events. If these can be implemented directly in the command-handler and never touch the domain model, this allows you to slim down the domain model even more. Also, if you were to do event sourcing without CQRS, you no longer have a database containing the current state (only the domain model would) which makes it difficult (or impossible) to support ad-hoc querying and/or reporting that is common in most business software. Of course CQRS provides some great scalability benefits, not only scalability but I have to assume that it provides extremely low latency for most operations, especially if you have an asynchronous event bus. I know Greg says that you get a 3x scaling (Commands, Queries, Client) of your ability to perform parallel development, but IMHO, it seems like it only provides 1.5x scaling since even without CQRS you’re going to have your client loosely coupled to your domain - which is still a great benefit to be able to realize. Questions / Concerns If all the queries against an aggregate get pulled out to the Query layer, what if the only commands for that aggregate can be handled in a “pass-through” manner with the command handler directly generating events. Is it possible to have an aggregate that isn’t modeled in the domain model? Are there any issues or downsides to this? I know in the feedback from my previous posts it was suggested that having one domain model handling both commands and queries requires implementing a lot of traversals between objects that wouldn’t be necessary if it was only servicing commands. My question is, do you include traversals in your domain model based on the needs of the code, or based on the conceptual domain model? If none of my Commands require a Customer.Orders traversal, but the conceptual domain includes the concept of a set of orders belonging to a customer – should I model that in my domain model or not? I like the idea of using the Query side of the architecture as a place to put junior devs where the risk of them screwing something up has minimal impact. But I’m not sold on the idea that you can actually outsource it. Like I said in one of my comments on my previous post, the code to handle a query and generate DTO’s is going to be dead simple, but the code to process events and apply them to the tables on the query side is going to require a significant amount of domain knowledge to know which events to listen for to update each of the de-normalized tables (and what changes need to be made when each event is processed). I don’t know about everybody else, but having Indian/Russian/whatever outsourced developers have to do anything that requires significant domain knowledge has never been successful in my experience. And if you need to spec out for each new query which events to listen to and what to do with each one, well that’s probably going to be just as much work to document as it would be to just implement it. Greg made the point in a comment that doing an aggregate query like “Total Sales By Customer” is going to be inefficient if you use event sourcing but not CQRS. I don’t understand why that would be the case. I imagine in that case you’d simply have a method/property on the Customer object that calculated total sales for that customer by enumerating over the Orders collection. Then the application services layer would generate DTO’s off of the Customers collection that included say the CustomerID, CustomerName, TotalSales, or whatever the case may be. As long as you use a snapshotting implementation, I don’t see why that would be anymore inefficient in a DDD+Event Sourcing implementation than in a typical DDD implementation. Like I mentioned in my last post I still have some questions about query logic that haven’t been answered yet, but before I start asking those I want to make sure I have a strong grasp on what benefits CQRS provides.  My main concern with the query logic was that I know I could just toss it all into the query side, but I was concerned that I would be losing the benefits of using CQRS in the first place if I did that.  I want to elaborate more on this though with some example situations in an upcoming post.

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• The way I think about Diagnostic tools

  - by Daniel Moth

  Every software has issues, or as we like to call them "bugs". That is not a discussion point, just a mere fact. It follows that an important skill for developers is to be able to diagnose issues in their code. Of course we need to advance our tools and techniques so we can prevent bugs getting into the code (e.g. unit testing), but beyond designing great software, diagnosing bugs is an equally important skill. To diagnose issues, the most important assets are good techniques, skill, experience, and maybe talent. What also helps is having good diagnostic tools and what helps further is knowing all the features that they offer and how to use them. The following classification is how I like to think of diagnostics. Note that like with any attempt to bucketize anything, you run into overlapping areas and blurry lines. Nevertheless, I will continue sharing my generalizations ;-) It is important to identify at the outset if you are dealing with a performance or a correctness issue. If you have a performance issue, use a profiler. I hear people saying "I am using the debugger to debug a performance issue", and that is fine, but do know that a dedicated profiler is the tool for that job. Just because you don't need them all the time and typically they cost more plus you are not as familiar with them as you are with the debugger, doesn't mean you shouldn't invest in one and instead try to exclusively use the wrong tool for the job. Visual Studio has a profiler and a concurrency visualizer (for profiling multi-threaded apps). If you have a correctness issue, then you have several options - that's next :-) This is how I think of identifying a correctness issue Do you want a tool to find the issue for you at design time? The compiler is such a tool - it gives you an exact list of errors. Compilers now also offer warnings, which is their way of saying "this may be an error, but I am not smart enough to know for sure". There are also static analysis tools, which go a step further than the compiler in identifying issues in your code, sometimes with the aid of code annotations and other times just by pointing them at your raw source. An example is FxCop and much more in Visual Studio 11 Code Analysis. Do you want a tool to find the issue for you with code execution? Just like static tools, there are also dynamic analysis tools that instead of statically analyzing your code, they analyze what your code does dynamically at runtime. Whether you have to setup some unit tests to invoke your code at runtime, or have to manually run your app (and interact with it) under the tool, or have to use a script to execute your binary under the tool… that varies. The result is still a list of issues for you to address after the analysis is complete or a pause of the execution when the first issue is encountered. If a code path was not taken, no analysis for it will exist, obviously. An example is the GPU Race detection tool that I'll be talking about on the C++ AMP team blog. Another example is the MSR concurrency CHESS tool. Do you want you to find the issue at design time using a tool? Perform a code walkthrough on your own or with colleagues. There are code review tools that go beyond just diffing sources, and they help you with that aspect too. For example, there is a new one in Visual Studio 11 and searching with my favorite search engine yielded this article based on the Developer Preview. Do you want you to find the issue with code execution? Use a debugger - let’s break this down further next. This is how I think of debugging: There is post mortem debugging. That means your code has executed and you did something in order to examine what happened during its execution. This can vary from manual printf and other tracing statements to trace events (e.g. ETW) to taking dumps. In all cases, you are left with some artifact that you examine after the fact (after code execution) to discern what took place hoping it will help you find the bug. Learn how to debug dump files in Visual Studio. There is live debugging. I will elaborate on this in a separate post, but this is where you inspect the state of your program during its execution, and try to find what the problem is. More from me in a separate post on live debugging. There is a hybrid of live plus post-mortem debugging. This is for example what tools like IntelliTrace offer. If you are a tools vendor interested in the diagnostics space, it helps to understand where in the above classification your tool excels, where its primary strength is, so you can market it as such. Then it helps to see which of the other areas above your tool touches on, and how you can make it even better there. Finally, see what areas your tool doesn't help at all with, and evaluate whether it should or continue to stay clear. Even though the classification helps us think about this space, the reality is that the best tools are either extremely excellent in only one of this areas, or more often very good across a number of them. Another approach is to offer a toolset covering all areas, with appropriate integration and hand off points from one to the other. Anyway, with that brain dump out of the way, in follow-up posts I will dive into live debugging, and specifically live debugging in Visual Studio - stay tuned if that interests you. Comments about this post by Daniel Moth welcome at the original blog.

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• Recent Innovations to ILOM

  - by B.Koch

  by Josh Rosen If you are wondering how Oracle can make some of the most advanced, reliable, and fault tolerant servers on the market, look no further than Oracle Integrated Lights Out Manager or ILOM.  We build ILOM into every server we create, from Oracle x86 Systems such as X3-2 to the SPARC T-Series family. Oracle ILOM is an embedded service processor, but it's really more than that.  It's a computer within a computer.  It's smart, it's tightly integrated into all aspects of the server's operation, and it's a big reason why Oracle servers are used for some of the most mission-critical workloads out there. To understand the value of ILOM, there is no better place to start than its fault management capability.  We have taken the sophisticated fault management architecture from Solaris, developed and refined over a decade, and built it into each and every ILOM. ILOM detects a potential issue at its earliest stage, watching low-level sensors.   If the root cause of a problem is not clear from a single error reading, ILOM will look for other clues and combine multiple pieces of information to correctly identify a failing component. ILOM provides peace of mind. We tailor our fault management for each new server platform that we produce.  You can rest assured that it's always actively keeping the server healthy.  And if there is a problem, you can be confident it will let you know by sending you a notification by e-mail or trap. We also heard IT managers tell us they needed a Ph.D. in computer engineering to manage today's servers. It doesn't have to be that way.  Thanks to the latest innovations to Oracle ILOM, we present hardware inventory and status in way that makes sense – to anyone.  Green means everything is healthy and red means something is wrong.  When a component needs to be replaced a clear message indicates where the problem is and points you at a knowledge article about that problem.  It's that simple. Simpler management and simple interfaces mean reduced complexity and lower costs to manage.  And we know that's really important. ILOM does all this while also providing advanced service processor features you depend on for managing enterprise class systems.  You can remotely control the server power, interact with a virtual video console for the server, and mount media on the server remotely.  There is no need to spend money on a KVM switch to get this functionality. And when people hear how advanced ILOM is, they can't believe ILOM is free.  All features are enabled and included with each Oracle server that you buy.  There are no advanced licenses you need to purchase or features to unlock. Configuring ILOM has also never been easier.  It is now possible to configure almost all aspects of the server directly from ILOM.  This includes changing BIOS settings, persistently modifying boot order, and optimizing power settings -- all directly from ILOM. But Oracle's innovation does not stop with ILOM.  Oracle has engineered Oracle Enterprise Manager Ops Center to integrate directly with ILOM, providing centralized management across all of our servers. Ops Center will discover each of your Oracle servers over the network by searching for ILOMs.  When it finds one, it knows how to communicate with ILOM to monitoring and configure that server from application to disk. Since every server that Oracle produces, from x86 Systems to SPARC T-Series up and down the line, comes with Oracle ILOM, you can manage all Oracle servers in the same way.  And while all of our servers may have different components on the inside, each with their specialized functions, the way you integrate them and the way you monitor and manage them is exactly the same. Oracle ILOM is state-of-art.  If you are looking for a server that make systems management simple and is easy to integrate and maintain, check out the latest advances to Oracle ILOM. Josh Rosen is a Principal Product Manager at Oracle and previously spent more than a decade as a developer and architect of system management software. Josh has worked on system management for many of Oracle's hardware products ranging from the earliest blade systems to the latest Oracle x86 servers.

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• "corrupted filesystem tarfile - corrupted package archive" error

  - by Justin

  I was trying to install a program and it said that my dependencies were unmet, and that I should run, sudo apt-get -f install. I have moved everything I didn't need in /etc/apt/sources.list.d/ into the trash. My source.list is all Natty while I am running Oneiric. So maybe I need a new source.list? But here are the things I have: justin@justin-000:~$ sudo apt-get -f install [sudo] password for justin: Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following extra packages will be installed: linux-image-3.0.0-13-generic Suggested packages: fdutils linux-doc-3.0.0 linux-source-3.0.0 linux-tools The following NEW packages will be installed: linux-image-3.0.0-13-generic 0 upgraded, 1 newly installed, 0 to remove and 3 not upgraded. 2 not fully installed or removed. Need to get 0 B/36.5 MB of archives. After this operation, 117 MB of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 270736 files and directories currently installed.) Unpacking linux-image-3.0.0-13-generic (from .../linux-image-3.0.0-13- generic_3.0.0-13.22_i386.deb) ... Done. dpkg: error processing /var/cache/apt/archives/linux-image-3.0.0-13 generic_3.0.0-13.22_i386.deb (--unpack): corrupted filesystem tarfile - corrupted package archive No apport report written because MaxReports is reached already dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Examining /etc/kernel/postrm.d . run-parts: executing /etc/kernel/postrm.d/initramfs-tools 3.0.0-13-generic /boot/vmlinuz-3.0.0-13-generic run-parts: executing /etc/kernel/postrm.d/zz-extlinux 3.0.0-13-generic /boot/vmlinuz-3.0.0-13-generic P: Checking for EXTLINUX directory... found. P: Writing config for /boot/vmlinuz-3.0.0-12-generic... P: Writing config for /boot/vmlinuz-2.6.38-11-generic... P: Installing debian theme... done. run-parts: executing /etc/kernel/postrm.d/zz-update-grub 3.0.0-13-generic /boot/vmlinuz-3.0.0-13-generic Errors were encountered while processing: /var/cache/apt/archives/linux-image-3.0.0-13-generic_3.0.0-13.22_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1) justin@justin-000:~$ sudo apt-get update justin@justin-000:~$ sudo apt-get update Ign dl.google.com stable InRelease Ign dl.google.com stable InRelease Get:1dl.google.com stable Release.gpg [198 B] Ign us.archive.ubuntu.com oneiric InRelease Ign us.archive.ubuntu.com oneiric-security InRelease Ign http://us.archive.ubuntu.com oneiric-updates InRelease Get:2 dl.google.com stable Release.gpg [198 B] Get:3 dl.google.com stable Release [1,347 B] Get:4 dl.google.com stable Release [1,338 B] Hit us.archive.ubuntu.com oneiric Release.gpg Hit us.archive.ubuntu.com oneiric-security Release.gpg Get:5/dl.google.com stable/main i386 Packages [1,220 B] Hit tp://us.archive.ubuntu.com oneiric-updates Release.gpg Ign tp://dl.google.com stable/main TranslationIndex Get:6 tp://dl.google.com stable/main i386 Packages [464 B] Ign ttp://ppa.launchpad.net oneiric InRelease Hit ttp://us.archive.ubuntu.com oneiric Release Ign ttp://ppa.launchpad.net oneiric InRelease Ign ttp://dl.google.com stable/main TranslationIndex Hit ttp://ppa.launchpad.net oneiric Release.gpg Hit ttp://us.archive.ubuntu.com oneiric-security Release Hit ttp://ppa.launchpad.net oneiric Release.gpg Hit ttp://us.archive.ubuntu.com oneiric-updates Release Hit ttp://us.archive.ubuntu.com oneiric/main Sources Hit ttp://us.archive.ubuntu.com oneiric/restricted Sources Hit ttp://us.archive.ubuntu.com oneiric/universe Sources Hit ttp://us.archive.ubuntu.com oneiric/multiverse Sources Hit ttp://us.archive.ubuntu.com oneiric/main i386 Packages Hit ttp://ppa.launchpad.net oneiric Release Hit ttp://us.archive.ubuntu.com oneiric/restricted i386 Packages Hit ttp://us.archive.ubuntu.com oneiric/universe i386 Packages Hit ttp://us.archive.ubuntu.com oneiric/multiverse i386 Packages Hit ttp://us.archive.ubuntu.com oneiric/main TranslationIndex Hit ttp://us.archive.ubuntu.com oneiric/multiverse TranslationIndex Hit ://us.archive.ubuntu.com oneiric/restricted TranslationIndex Hit htp://us.archive.ubuntu.com oneiric/universe TranslationIndex Hit htp://us.archive.ubuntu.com oneiric-security/main Sources Hit ttp://us.archive.ubuntu.com oneiric-security/restricted Sources Hit ttp://ppa.launchpad.net oneiric Release Hit ttp://us.archive.ubuntu.com oneiric-security/universe Sources Hit tp://us.archive.ubuntu.com oneiric-security/multiverse Sources Hit htp://us.archive.ubuntu.com oneiric-security/main i386 Packages Hit tp://us.archive.ubuntu.com oneiric-security/restricted i386 Packages Hit ttp://us.archive.ubuntu.com oneiric-security/universe i386 Packages Hit ttp://us.archive.ubuntu.com oneiric-security/multiverse i386 Packages Hit htp://ppa.launchpad.net oneiric/main Sources Hit ttp://ppa.launchpad.net oneiric/main i386 Packages Ign htp://ppa.launchpad.net oneiric/main TranslationIndex Hit ttp://us.archive.ubuntu.com oneiric-security/main TranslationIndex Hit ttp://us.archive.ubuntu.com oneiric-security/multiverse TranslationIndex Hit htp://us.archive.ubuntu.com oneiric-security/restricted TranslationIndex Hit htp://us.archive.ubuntu.com oneiric-security/universe TranslationIndex Ign htp://dl.google.com stable/main Translation-en_US Hit htp://us.archive.ubuntu.com oneiric-updates/main Sources Hit htp://us.archive.ubuntu.com oneiric-updates/restricted Sources Hit tp://us.archive.ubuntu.com oneiric-updates/universe Sources Hit htp://us.archive.ubuntu.com oneiric-updates/multiverse Sources Hit htp://us.archive.ubuntu.com oneiric-updates/main i386 Packages Ign htp://dl.google.com stable/main Translation-en Hit ttp://ppa.launchpad.net oneiric/main Sources Hit htp://ppa.launchpad.net oneiric/main i386 Packages Hit ttp://us.archive.ubuntu.com oneiric-updates/restricted i386 Packages Ign htp://dl.google.com stable/main Translation-en_US Ign htp://ppa.launchpad.net oneiric/main TranslationIndex Hit hp://us.archive.ubuntu.com oneiric-updates/universe i386 Packages Hit ttp://us.archive.ubuntu.com oneiric-updates/multiverse i386 Packages Hit htp://us.archive.ubuntu.com oneiric-updates/main TranslationIndex Hit htp://us.archive.ubuntu.com oneiric-updates/multiverse TranslationIndex Hit htp://us.archive.ubuntu.com oneiric-updates/restricted TranslationIndex Ign htp://dl.google.com stable/main Translation-en Hit htp://us.archive.ubuntu.com oneiric-updates/universe TranslationIndex Hit ttp://us.archive.ubuntu.com oneiric/main Translation-en Hit ttp://us.archive.ubuntu.com oneiric/multiverse Translation-en Hit htp://us.archive.ubuntu.com oneiric/restricted Translation-en Hit htp://us.archive.ubuntu.com oneiric/universe Translation-en Hit htp://us.archive.ubuntu.com oneiric-security/main Translation-en Hit hp://us.archive.ubuntu.com oneiric-security/multiverse Translation-en Hit htp://us.archive.ubuntu.com oneiric-security/restricted Translation-en Hit htp://us.archive.ubuntu.com oneiric-security/universe Translation-en Hit htp://us.archive.ubuntu.com oneiric-updates/main Translation-en Hit htp://us.archive.ubuntu.com oneiric-updates/multiverse Translation-en Hit htp://us.archive.ubuntu.com oneiric-updates/restricted Translation-en Hit htp://us.archive.ubuntu.com oneiric-updates/universe Translation-en Ign htp://ppa.launchpad.net oneiric/main Translation-en_US Ign htt://ppa.launchpad.net oneiric/main Translation-en Ign htp://ppa.launchpad.net oneiric/main Translation-en_US Ign htp://ppa.launchpad.net oneiric/main Translation-en Fetched 4,765 B in 2s (2,158 B/s) Reading package lists... Done justin@justin-000:~$

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• How to get sound on macbook pro 4,1

  - by Thomas

  I have just installed Xubuntu 12.04.2. My soundcard is detected: thomas@thomas-pc:~$ sudo aplay -l **** List of PLAYBACK Hardware Devices **** Home directory /home/thomas not ours. card 0: Intel [HDA Intel], device 0: ALC889A Analog [ALC889A Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 1: ALC889A Digital [ALC889A Digital] Subdevices: 1/1 Subdevice #0: subdevice #0 Everything is put to max in alsamixer and nothing is muted (all the sliders are on OO. My speakers do not work, but when I plug in a headphone I hear it very soft. When I connect my stereo and put the sound VERY loud (3-blocks-of-complaining-neighbours loud) I hear it on a normal level but crackling. I added options snd-hda-intel model=mbp5 amixer set IEC958 off to at the end of /etc/modprobe.d/alsa-base.conf. When it's still not working I tried everything here: https://help.ubuntu.com/community/SoundTroubleshooting 1 >>> list-sinks 1 sink(s) available. * index: 0 name: <alsa_output.pci-0000_00_1b.0.analog-stereo> driver: <module-alsa-card.c> flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY state: SUSPENDED suspend cause: IDLE priority: 9959 volume: 0: 100% 1: 100% 0: 0.00 dB 1: 0.00 dB balance 0.00 base volume: 100% 0.00 dB volume steps: 65537 muted: no current latency: 0.00 ms max request: 0 KiB max rewind: 0 KiB monitor source: 0 sample spec: s16le 2ch 44100Hz channel map: front-left,front-right Stereo used by: 0 linked by: 0 configured latency: 0.00 ms; range is 0.50 .. 371.52 ms card: 0 <alsa_card.pci-0000_00_1b.0> module: 4 properties: alsa.resolution_bits = "16" device.api = "alsa" device.class = "sound" alsa.class = "generic" alsa.subclass = "generic-mix" alsa.name = "ALC889A Analog" alsa.id = "ALC889A Analog" alsa.subdevice = "0" alsa.subdevice_name = "subdevice #0" alsa.device = "0" alsa.card = "0" alsa.card_name = "HDA Intel" alsa.long_card_name = "HDA Intel at 0x9b500000 irq 46" alsa.driver_name = "snd_hda_intel" device.bus_path = "pci-0000:00:1b.0" sysfs.path = "/devices/pci0000:00/0000:00:1b.0/sound/card0" device.bus = "pci" device.vendor.id = "8086" device.vendor.name = "Intel Corporation" device.product.name = "82801H (ICH8 Family) HD Audio Controller" device.form_factor = "internal" device.string = "front:0" device.buffering.buffer_size = "65536" device.buffering.fragment_size = "32768" device.access_mode = "mmap+timer" device.profile.name = "analog-stereo" device.profile.description = "Analog Stereo" device.description = "Built-in Audio Analog Stereo" alsa.mixer_name = "Realtek ALC889A" alsa.components = "HDA:10ec0885,106b3a00,00100103" module-udev-detect.discovered = "1" device.icon_name = "audio-card-pci" ports: analog-output-speaker: Speakers (priority 10000, available: unknown) properties: analog-output-headphones: Headphones (priority 9000, available: no) properties: active port: <analog-output-speaker> 2 and 3: Doesn't seem an permission issue, the sound is very far away (See opening paragraph). 4 thomas@thomas-pc:~$ sudo aplay -l **** List of PLAYBACK Hardware Devices **** Home directory /home/thomas not ours. card 0: Intel [HDA Intel], device 0: ALC889A Analog [ALC889A Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 1: ALC889A Digital [ALC889A Digital] Subdevices: 1/1 Subdevice #0: subdevice #0 5 thomas@thomas-pc:~$ find /lib/modules/`uname -r` | grep snd /lib/modules/3.2.0-48-generic/kernel/sound/core/snd-hwdep.ko /lib/modules/3.2.0-48-generic/kernel/sound/core/snd-pcm.ko [.. huge lists continues ..] /lib/modules/3.2.0-48-generic/kernel/sound/pcmcia/pdaudiocf/snd-pdaudiocf.ko /lib/modules/3.2.0-48-generic/kernel/sound/pcmcia/vx/snd-vxpocket.ko thomas@thomas-pc:~$ 6 thomas@thomas-pc:~$ lspci -v | grep -A7 -i "audio" 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03) Subsystem: Apple Inc. Device 00a4 Flags: bus master, fast devsel, latency 0, IRQ 46 Memory at 9b500000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel 7 I guess it's supported. Linux mint and Xubuntu 13.04 had no trouble with sounds. Everything worked out of the box Thanks in advance Edit: alsa-info.sh output: WARNING: /etc/modprobe.d/alsa-base.conf line 45: ignoring bad line starting with 'amixer' ALSA Information Script v 0.4.62 -------------------------------- This script visits the following commands/files to collect diagnostic information about your ALSA installation and sound related hardware. dmesg lspci lsmod aplay amixer alsactl /proc/asound/ /sys/class/sound/ ~/.asoundrc (etc.) See './alsa-info.sh --help' for command line options. WARNING: /etc/modprobe.d/alsa-base.conf line 45: ignoring bad line starting with 'amixer' Automatically upload ALSA information to www.alsa-project.org? [y/N] : y Uploading information to www.alsa-project.org ... Done! Your ALSA information is located at http://www.alsa-project.org/db/?f=6cffc584284d4c0b266eb53249824ef83d6c4e3e Please inform the person helping you. thomas@thomas-pc:~$

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• Geocaching - World wide treasure hunt

  I'm not quite sure how I came across this topic but actually I find it absolutely interesting, challenging and most of all a great fun for the family and friends. The interesting part is for sure that you can follow other peoples treasures and their preferred locations where a cache might be hidden. Of course, it wont be easy to find a cache after all. Sometimes there are even 'mystery caches' which have either riddles, further instructions or little brain games for you in order to find the actual cache - that's the challenge. And last but not least, those caches are hidden outdoor. A great experience to explore nature either on your own, or your family especially with children, or as a treasure hunting pack with a couple of friends. What is geocaching? It's a high-tech outdoor treasure hunting game that's a great way to explore the world with friends, family or on your own. Participants use GPS-enabled devices to locate hidden containers called geocaches. There are over one million geocaches hidden around the world today, waiting for you to find them. Visit Geocaching.com to search for geocaches near you.(Source: Referral Email of geocaching.com) Checkout the Geocaching 101 for further details and information. They also provide a video channel on YouTube. Which equipment do I need? Any GPS-enabled device is sufficient to go onto the hunt. I'm going to start our geocaching experience equipped with my Samsung Galaxy Tab. Additionally, I installed a geocaching.com client called c:geo that hopefully assists me soon. Combined with a map app like Google Maps and a nice Compass app you should be fully equipped and ready to go. I guess, that even a car navigation system is perfect for that task. Later on, with more experience and demand for technology (or precision) it might be interesting to opt-in for a pure GPS device, like a Garmin or any other brand on the market. {loadposition content_adsense} What is a geocache and what does it contain? In its simplest form, a cache always contains a logbook or logsheet for you to log your find. Larger caches may contain a logbook and any number of items. These items turn the adventure into a true treasure hunt. You never know what the cache owner or visitors to the cache may have left for you to enjoy. Remember, if you take something, leave something of equal or greater value in return. It is recommended that items in a cache be individually packaged in a clear, zipped plastic bag to protect them from the elements. Finding your first geocache Well, first you have to have interest to pick up the challenge. Then you have to check out the Geocache directory on geocaching.com. They have recommendations for beginner's caches but you are free to choose any. Actually, we have a Mystery Cache very close to our base, and I guess that we are going for that one on our first trip. Anyway, there is a very informative guide on the website which should answer all your questions about starting your new outdoor adventure. For sure, it's going to be rewarding. Team up with friends and family Especially as a beginner there might be misunderstandings in handling the GPS coordinates, the compass, or the map, and even finding the container at the documented position isn't easy in the first place. Luckily, there are logbook reports online from other hunters, and most of the time there are even 'spoiler' images available. But also bear in mind, that a geocache might have been removed or is lost due to unconscious people or whatever other reasons. Don't be disappointed in case that you can't find anything... There be nothing anymore. A general recommendation in this case would be to replace the missing container with a new one, and give feedback to the original owner about the state of that particular location. After all, it's about fun and active participation in a world-wide community. Geocaches in Mauritius? Yes, there are currently about 45 geocaches spread all over the island, and even a single in Rodriguez - that's gonna be a tough one. Hopefully, we will get increasing numbers as Geocaching.com allows, no better, even encourages you to hide new containers at your locations of choice. I think this is going to be real fun for us during the upcoming weeks and months. Especially, when we are travelling to other countries and transfer so-called trackable items between geocaches. On my first impression, Geocaching.com seems to be very mature, open and community-oriented. There are literally hundreds of thousands geocache 'hunters' all over the world. And usually finding a container remote from your home is very rewarding. I'll keep you updated in these matters during the next months to come...

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• Data Mining Resources

  - by Dejan Sarka

  There are many different types of analyses, each one with its own pros and cons. Relational reports have a predefined structure, and end users cannot change it. They are simple to use for end users. Reports can use real-time data and snapshots of data to show the state of a report at specific points in time. One of the drawbacks is that report authoring is limited to IT pros and advanced users. Any kind of dynamic restructuring is very limited. If real-time data is used for a report, the report has a negative impact on the performance of the source system. Processing of the reports might be slow because the data comes from relational database management systems, which are not optimized for reporting only. If you create a semantic model of your data, your end users can create ad-hoc report structures. However, the development is more complex because a developer is needed to create these semantic models. For OLAP, you typically use specialized database management systems. You get lightning speed of analyses. End users can use rich and thin clients to interactively change the structure of the report. Typically, they do it graphically. However, the development of an OLAP system is many times quite complex. It involves the preparation and maintenance of an enterprise data warehouse and OLAP cubes. In order to exploit the possibility of real-time restructuring of reports, the users must be both active and educated. The data is usually stale, as it is loaded into data warehouses and OLAP cubes with a scheduled process. With data mining, a structure is not selected in advance; it searches for the structure. As a result, data mining can give you the most valuable results because you can discover patterns you did not expect. A data mining model structure is limited only by the attributes that you use to train the model. One of the drawbacks is that a lot of knowledge is needed for a successful data mining project. End users have to understand the results. Subject matter experts and IT professionals need to understand business problem thoroughly. The development might be sometimes even more complex than the development of OLAP cubes. Each type of analysis has its own place in an enterprise system. SQL Server has tools for all kinds of analyses. However, data mining is the most advanced way of analyzing the data; this is the “I” in BI. In order to get the most out of it, you need to learn quite a lot. In this blog post, I am gathering together resources for learning, including forthcoming events. Books Multiple authors: SQL Server MVP Deep Dives – I wrote an introductory data mining chapter there. Erik Veerman, Teo Lachev and Dejan Sarka: MCTS Self-Paced Training Kit (Exam 70-448): Microsoft SQL Server 2008 - Business Intelligence Development and Maintenance – you can find a good overview of a complete BI solution, including data mining, in this book. Jamie MacLennan, ZhaoHui Tang, and Bogdan Crivat: Data Mining with Microsoft SQL Server 2008 – can’t miss this book if you want to mine your data with SQL Server tools. Michael Berry, Gordon Linoff: Mastering Data Mining: The Art and Science of Customer Relationship Management – data mining from both, business and technical perspective. Dorian Pyle: Data Preparation for Data Mining – an in-depth book about data preparation. Thomas and Ronald Wonnacott: Introductory Statistics – if you thought that you could get away without statistics, then you are not serious about data mining. Jiawei Han and Micheline Kamber: Data Mining Concepts and Techniques – in-depth explanation of the most popular data mining algorithms. Michael Berry and Gordon Linoff: Data Mining Techniques – another book that explains data mining algorithms, more fro a business perspective. Paolo Guidici: Applied Data Mining – very mathematical book, only if you enjoy statistics and mathematics in general. Forthcoming presentations I am presenting two data mining related sessions during the PASS Summit in Charlotte, NC: Wednesday, October 16th, 2013 - Fraud Detection: Notes from the Field – I am showing how to use data mining for a specific business problem. The presentation is based on real-life projects. Friday, October 18th: Excel 2013 Advanced Analytics – I am focusing on Excel Data Mining Add-ins, and how to use them together with Power Pivot and other add-ins. This is the most you can get out of Excel. Sinergija 2013, Belgrade, Serbia Tuesday, October 22nd: Excel 2013 Analytics to the Max – another presentation focusing on the most advanced analytics you can get in Excel. SQL Rally Amsterdam, Netherlands Thursday, November 7th: Advanced Analytics in Excel 2013 – and again I am presenting about data mining in Excel. Why three different titles for the same presentation? I don’t know, I guess I forgot the name I proposed every time right after I sent the proposal. Courses Data Mining with SQL Server 2012 – I wrote a 3-day course for SolidQ. If you are interested in this course, which I could also deliver in a shorter seminar way, you can contact your closes SolidQ subsidiary, or, of course, me directly on addresses [email protected] or [email protected]. This course could also complement the existing courseware portfolio of training providers, which are welcome to contact me as well. OK, now you know: no more excuses, start learning data mining, get the most out of your data

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• Who is Jeremiah Owyang?

  - by Michael Hylton

  Q: What’s your current role and what career path brought you here? J.O.: I'm currently a partner and one of the founding team members at Altimeter Group.  I'm currently the Research Director, as well as wear the hat of Industry Analyst. Prior to joining Altimeter, I was an Industry Analyst at Forrester covering Social Computing, and before that, deployed and managed the social media program at Hitachi Data Systems in Santa Clara.  Around that time, I started a career blog called Web Strategy which focused on how companies were using the web to connect with customers --and never looked back. Q: As an industry analyst, what are you focused on these days? J.O.: There are three trends that I'm focused my research on at this time:  1) The Dynamic Customer Journey:  Individuals (both b2c and b2b) are given so many options in their sources of data, channels to choose from and screens to consume them on that we've found that at each given touchpoint there are 75 potential permutations.  Companies that can map this, then deliver information to individuals when they need it will have a competitive advantage and we want to find out who's doing this.  2) One of the sub themes that supports this trend is Social Performance.  Yesterday's social web was disparate engagement of humans, but the next phase will be data driven, and soon new technologies will emerge to help all those that are consuming, publishing, and engaging on the social web to be more efficient with their time through forms of automation.  As you might expect, this comes with upsides and downsides.  3) The Sentient World is our research theme that looks out the furthest as the world around us (even inanimate objects) become 'self aware' and are able to talk back to us via digital devices and beyond.  Big data, internet of things, mobile devices will all be this next set. Q: People cite that the line between work and life is getting more and more blurred. Do you see your personal life influencing your professional work? J.O.: The lines between our work and personal lives are dissolving, and this leads to a greater upside of being always connected and have deeper relationships with those that are not.  It also means a downside of society expectations that we're always around and available for colleagues, customers, and beyond.  In the future, a balance will be sought as we seek to achieve the goals of family, friends, work, and our own personal desires.  All of this is being ironically written at 430 am on a Sunday am.  Q: How can people keep up with what you’re working on? J.O.: A great question, thanks.  There are a few sources of information to find out, I'll lead with the first which is my blog at web-strategist.com.  A few times a week I'll publish my industry insights (hires, trends, forces, funding, M&A, business needs) as well as on twitter where I'll point to all the news that's fit to print @jowyang.  As my research reports go live (we publish them for all to read --called Open Research-- at no cost) they'll emerge on my blog, or checkout the research tab to find out more now.  http://www.web-strategist.com/blog/research/ Q: Recently, you’ve been working with us here at Oracle on something exciting coming up later this week. What’s on the horizon?  J.O.: Absolutely! This coming Thursday, September 13th, I’m doing a webcast with Oracle on “Managing Social Relationships for the Enterprise”. This is going to be a great discussion with Reggie Bradford, Senior Vice President of Product Development at Oracle and Christian Finn, Senior Director of Product Management for Oracle WebCenter. I’m looking forward to a great discussion around all those issues that so many companies are struggling with these days as they realize how much social media is impacting their business. It’s changing the way your customers and employees interact with your brand. Today it’s no longer a matter of when to become a social-enabled enterprise, but how to become a successful one. Q: You’ve been very actively pursued for media interviews and conference and company speaking engagements – anything you’d like to share to give us a sneak peak of what to expect on Thursday’s webcast?  J.O.: Below is a 15 minute video which encapsulates Altimeter’s themes on the Dynamic Customer Journey and the Sentient World. I’m really proud to have taken an active role in the first ever LeWeb outside of Paris. This one, which was featured in downtown London across the street from Westminster Abbey was sold out. If you’ve not heard of LeWeb, this is a global Internet conference hosted by Loic and Geraldine Le Meur, a power couple that stem from Paris but are also living in Silicon Valley, this is one of my favorite conferences to connect with brands, technology innovators, investors and friends. Altimeter was able to play a minor role in suggesting the theme for the event “Faster Than Real Time” which stems off previous LeWebs that focused on the “Real time web”. In this radical state, companies are able to anticipate the needs of their customers by using data, technology, and devices and deliver meaningful experiences before customers even know they need it. I explore two of three of Altimeter’s research themes, the Dynamic Customer Journey, and the Sentient World in my speech, but due to time, did not focus on Adaptive Organization.

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• Out of disk space - /boot at 100%

  - by uvasal

  My /boot is at 100%. When I run aptitude search ~ilinux-image I'm getting loads of unused images. When I try to delete one of them (after checking which one is currently in use by doing uname -r), e.g apt-get autoremove linux-image-3.2.0-44-generic I get: Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: linux-generic : Depends: linux-headers-generic (= 3.2.0.51.61) but 3.2.0.54.64 is to be installed linux-server : Depends: linux-headers-server (= 3.2.0.51.61) but 3.2.0.54.64 is to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). And running apt-get -f install throws No space left on device. I've also tried doing apt-get purge but I am getting the same thing. Output of df -h and dpkg -l linux-*.: root@hb2088:/srv/www# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 9.4G 3.0G 6.0G 34% / udev 301M 4.0K 301M 1% /dev tmpfs 124M 228K 124M 1% /run none 5.0M 0 5.0M 0% /run/lock none 309M 0 309M 0% /run/shm /dev/sda1 92M 91M 0 100% /boot root@hb2088:/srv/www# dpkg -l linux-* Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Description +++-====================================================-====================================================-======================================================================================================================== un linux-doc-3.2.0 <none> (no description available) ii linux-firmware 1.79.6 Firmware for Linux kernel drivers iU linux-generic 3.2.0.51.61 Complete Generic Linux kernel un linux-headers <none> (no description available) un linux-headers-3 <none> (no description available) un linux-headers-3.0 <none> (no description available) ii linux-headers-3.2.0-44 3.2.0-44.69 Header files related to Linux kernel version 3.2.0 ii linux-headers-3.2.0-44-generic 3.2.0-44.69 Linux kernel headers for version 3.2.0 on 64 bit x86 SMP ii linux-headers-3.2.0-45 3.2.0-45.70 Header files related to Linux kernel version 3.2.0 ii linux-headers-3.2.0-45-generic 3.2.0-45.70 Linux kernel headers for version 3.2.0 on 64 bit x86 SMP ii linux-headers-3.2.0-48 3.2.0-48.74 Header files related to Linux kernel version 3.2.0 ii linux-headers-3.2.0-48-generic 3.2.0-48.74 Linux kernel headers for version 3.2.0 on 64 bit x86 SMP ii linux-headers-3.2.0-51 3.2.0-51.77 Header files related to Linux kernel version 3.2.0 ii linux-headers-3.2.0-51-generic 3.2.0-51.77 Linux kernel headers for version 3.2.0 on 64 bit x86 SMP ii linux-headers-3.2.0-52 3.2.0-52.78 Header files related to Linux kernel version 3.2.0 ii linux-headers-3.2.0-52-generic 3.2.0-52.78 Linux kernel headers for version 3.2.0 on 64 bit x86 SMP iU linux-headers-3.2.0-54 3.2.0-54.82 Header files related to Linux kernel version 3.2.0 iU linux-headers-3.2.0-54-generic 3.2.0-54.82 Linux kernel headers for version 3.2.0 on 64 bit x86 SMP iU linux-headers-generic 3.2.0.54.64 Generic Linux kernel headers iU linux-headers-server 3.2.0.54.64 Linux kernel headers on Server Equipment. un linux-image <none> (no description available) un linux-image-3.0 <none> (no description available) ii linux-image-3.2.0-44-generic 3.2.0-44.69 Linux kernel image for version 3.2.0 on 64 bit x86 SMP ii linux-image-3.2.0-45-generic 3.2.0-45.70 Linux kernel image for version 3.2.0 on 64 bit x86 SMP ii linux-image-3.2.0-48-generic 3.2.0-48.74 Linux kernel image for version 3.2.0 on 64 bit x86 SMP iF linux-image-3.2.0-51-generic 3.2.0-51.77 Linux kernel image for version 3.2.0 on 64 bit x86 SMP iF linux-image-3.2.0-52-generic 3.2.0-52.78 Linux kernel image for version 3.2.0 on 64 bit x86 SMP in linux-image-3.2.0-54-generic <none> (no description available) iU linux-image-generic 3.2.0.51.61 Generic Linux kernel image iU linux-image-server 3.2.0.51.61 Linux kernel image on Server Equipment. un linux-initramfs-tool <none> (no description available) un linux-kernel-headers <none> (no description available) un linux-kernel-log-daemon <none> (no description available) ii linux-libc-dev 3.2.0-52.78 Linux Kernel Headers for development un linux-restricted-common <none> (no description available) iU linux-server 3.2.0.51.61 Complete Linux kernel on Server Equipment. un linux-source-3.2.0 <none> (no description available) un linux-tools <none> (no description available) Output of du -sh /boot/*: root@hb2088:~# du -sh /boot/* 781K /boot/abi-3.2.0-44-generic 781K /boot/abi-3.2.0-45-generic 781K /boot/abi-3.2.0-48-generic 781K /boot/abi-3.2.0-51-generic 781K /boot/abi-3.2.0-52-generic 139K /boot/config-3.2.0-44-generic 139K /boot/config-3.2.0-45-generic 139K /boot/config-3.2.0-48-generic 139K /boot/config-3.2.0-51-generic 139K /boot/config-3.2.0-52-generic 1.6M /boot/grub 14M /boot/initrd.img-3.2.0-44-generic 14M /boot/initrd.img-3.2.0-45-generic 14M /boot/initrd.img-3.2.0-48-generic 12K /boot/lost+found 174K /boot/memtest86+.bin 176K /boot/memtest86+_multiboot.bin 2.8M /boot/System.map-3.2.0-44-generic 2.8M /boot/System.map-3.2.0-45-generic 2.8M /boot/System.map-3.2.0-48-generic 2.8M /boot/System.map-3.2.0-51-generic 2.8M /boot/System.map-3.2.0-52-generic 4.8M /boot/vmlinuz-3.2.0-44-generic 4.8M /boot/vmlinuz-3.2.0-45-generic 4.8M /boot/vmlinuz-3.2.0-48-generic 4.8M /boot/vmlinuz-3.2.0-51-generic 4.8M /boot/vmlinuz-3.2.0-52-generic

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• Oracle Fusion Applications User Experience Design Patterns: Feeling the Love after Launch

  - by mvaughan

  By Misha Vaughan, Oracle Applications User ExperienceIn the first video by the Oracle Applications User Experience team on the Oracle Partner Network, Vice President Jeremy Ashley said that Oracle is looking to expand the ecosystem of support for Oracle’s applications customers as they begin to assess their investment and adoption of Oracle Fusion Applications. Oracle has made a massive investment to maintain the benefits of the Fusion Applications User Experience. This summer, the Applications User Experience team released the Oracle Fusion Applications user experience design patterns.Design patterns help create consistent experiences across devices.The launch has been very well received:Angelo Santagata, Senior Principal Technologist and Fusion Middleware evangelist for Oracle,  wrote this to the system integrator community: “The web site is the result of many years of Oracle R&D into user interface design for Fusion Applications and features a really cool web app which allows you to visualise the UI components in action.”  Grant Ronald, Director of Product Management, Application Development Framework (ADF) said: “It’s a science I don't understand, but now I don't have to ... Now you can learn from the UX experience of Fusion Applications.”Frank Nimphius, Senior Principal Product Manager, Oracle (ADF) wrote about the launch of the design patterns for the ADF Code Corner, and Jürgen Kress, Senior Manager EMEA Alliances & Channels for Fusion MiddleWare and Service Oriented Architecture, (SOA), shared the news with his Partner Community. Oracle Twitter followers also helped spread the message about the design patterns launch: ?@bex – Brian Huff, founder and Chief Software Architect for Bezzotech, and Oracle ACE Director:“Nifty! The Oracle Fusion UX team just released new ADF design patterns.”@maiko_rocha, Maiko Rocha, Oracle Consulting Solutions Architect and Oracle FMW engineer: “Haven't seen any other vendor offer such comprehensive UX Design Patterns catalog for free!”@zirous_chad, Chad Thompson, Senior Solutions Architect for Zirous, Inc. and ADF Developer:Wow - @ultan and company did a great job with the Fusion UX PatternsWhat is a user experience design pattern?A user experience design pattern is a re-usable, usability tested functional blueprint for a particular user experience.  Some examples are guided processes, shopping carts, and search and search results.  Ultan O’Broin discusses the top design patterns every developer should know.The patterns that were just released are based on thousands of hours of end-user field studies, state-of-the-art user interface assessments, and usability testing.  To be clear, these are functional design patterns, not technical design patterns that developers may be used to working with.  Because we know there is a gap, we are putting together some training that will help close that gap.Who should care?This is an offering targeted primarily at Application Development Framework (ADF) developers. If you are faced with the following questions regarding Fusion Applications, you will want to know and learn more:•    How do I build something that looks like Fusion Applications?•    How do I build a next-generation application?•    How do I extend a Fusion Application and maintain the user experience?•    I don’t want to re-invent the wheel on the user interface, so where do I start?•    I need to build something that will eventually co-exist with Fusion Applications. How do I do that?These questions are relevant to partners with an ADF competency, individual practitioners, or small consultancies with an ADF specialization, and customers who are trying to shift their IT staff over to supporting Fusion Applications.Where you can find out more?OnlineOur Fusion User Experience design patterns maven is Ultan O’Broin. The Oracle Partner Network is helping our team bring this first e-seminar to you in order to go into a more detail on what this means and how to take advantage of it:? Webinar: Build a Better User Experience with Oracle: Oracle Fusion Applications Functional Design PatternsSept 20, 2012 , 10:30am-11:30am PacificDial-In:  1. 877-664-9137 / Passcode 102546?International:  706-634-9619  http://www.intercall.com/national/oracleuniversity/gdnam.htmlAccess the Live Event Or Via Webconference Access http://ouweb.webex.com  ?and enter this session number: 598036234At a Usergroup eventThe Fusion User Experience Advocates (FXA) are also going to be getting some deep-dive training on this content and can share it with local user groups.At OpenWorld Ultan O’Broin               Chris MuirIf you will be at OpenWorld this year, our own Ultan O’Broin will be visiting the ADF demopod to say hello, thanks to Shay Shmeltzer, Senior Group Manager for ADF outbound communication and at the OTN lounge: Monday 10-10:45, Tuesday 2:15-2:45, Wednesday 2:15-3:30 ?  Oracle JDeveloper and Oracle ADF,  Moscone South, Right - S-207? “ADF Meet and Greett”, OTN Lounge, Wednesday 4:30 And I cannot talk about OpenWorld and ADF without mentioning Chris Muir’s ADF EMG event: the Year After the Year Of the ADF Developer – Sunday, Sept 30 of OpenWorld. Chris has played host to Ultan and the Applications user experience message for his online community and is now a seasoned UX expert.Expect to see additional announcements about expanded and training on similar topics in the future.

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• Oracle’s Web Experience Management

  - by Christie Flanagan

  Today’s guest post on Oracle’s Web Experience Management comes from a member of our WebCenter Evangelist team, Noël Jaffré, a Principal Technologist based in France.Oracle’s Web Experience Management (WEM) solution enables organizations to optimize the online channel for driving marketing and customer experience management success. It empowers business users to manage the web presence and create rich and engaging online experiences for customers and prospects. Oracle's WEM platform provides a framework to simplify the integration of Oracle, third-party and custom-built applications. This framework essentially allows the creation and integration of applications using one single business interface called the WEM interface. It includes the following: Single sign-on access control for all integrated applications using the Central Authentication Service (CAS) component. A single centralized administration window for user, role, and native applications management including site management. Community server management, gadget server management as well as management for partner integrated technologies. A Representational State Transfer (REST) API for accessing WebCenter Sites data. REST services are supported on both Oracle WebCenter Sites and Oracle WebCenter Sites Satellite Server to leverage the satellite server cache. All REST requests are cached for web consuming applications as well for the high performance delivery of native applications on the mobile channel. Oracle WebCenter Sites’ Web Experience Management environment enables organizations to deliver a compelling online experience to customers by simplifying the deployment and management of sophisticated and engaging websites. The WebCenter Sites platform automates the entire process of managing web content including: Authoring:  Business users can easily contribute and manage web content in real-time, with intuitive interfaces and drag-and-drop content authoring and layout capabilities designed for the non-technical user. Contextual Content Targeting: Marketers are empowered to create and manage targeted campaigns with relevant recommendations and promotions based on the context of the session of the visitor such as his or her navigation history, user profile, language, location or other information shared during the visitor session. Content Publishing and Deployment: It offers advanced multi-site management capabilities for departmental or regional sites, as well as strong multi-lingual and multi-locale content management. The remote satellite server caching infrastructure provides high-performance, distributed caching, tuned to deliver high-volume, targeted and multi-lingual sites. Analytics and Optimization: Business users and marketers have the ability to measure the effectiveness of their online content and campaigns at a granular level. Editors and marketers can immediately determine whether a given article or promotion is relevant to a particular customer segment. User-generated Content: Marketers can enable blogs, comments, rating and reviews on the website.  All comments and reviews posted to the website can be moderated from the administrator interface either manually or automatically using filters, whitelists, blacklists or community based moderation. Personalized Gadget Dashboards:  Site managers can deploy gadgets, small applications using web content, individually or as part of dashboards containing multiple gadgets.  These gadget dashboards enable site visitors to create their own “MyPage” on a given site where they can select and customize the gadgets that the site administrator has made available.  Any gadget that conforms to the iGoogle/OpenSocial standard can be made available to site visitors, or they can be created within the WEM interface. Oracle's WEM platform also provides a unique environment for the delivery of a rich, multichannel online experience for site visitors through its advanced management modules for mobile. With Oracle’s WEM solution, it’s easy to control branding and deliver a consistent message while repurposing web content for publication to mobile devices, kiosks and much more. This distinctive approach provides: HTML5 Delivery: HTML5 delivery which includes native support for adaptive design that responds to the user’s computer screen resolution and orientation. The approach is less driven by the particular hardware and more driven by the user’s interactions with the device. In other words, this approach takes both the screen interactions (either cursor or touch) and screen sizes and orientation into consideration. A Unique Native Mobile Extension Environment for Contributors: From the WEM interface, a contributor can directly manage their mobile channel, using the tooling already in place for driving the traditional web presence. This includes the mobile presentation, as well as mobile insite editing, drag and drop page layout, and in-context recommendations and personalization. Optimized REST APIs for High Performance Content Delivery on Native Mobile Device Applications: WebCenter Sites’ REST API uses the underlying HTTP methods (GET, POST, PUT, DELETE) to interact with resources. Resources support two types of input and output formats -- XML and JSON. REST calls are customizable to optimize the interactions between the content repositories and the client applications. Caching is essential to decrease network loads and improve overall reliability and usability of the applications and user interactions. REST results are cached through the highly efficient Oracle WebCenter Sites caching architecture.

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• F# for the C# Programmer

  - by mbcrump

  Are you a C# Programmer and can’t make it past a day without seeing or hearing someone mention F#?  Today, I’m going to walk you through your first F# application and give you a brief introduction to the language. Sit back this will only take about 20 minutes. Introduction Microsoft's F# programming language is a functional language for the .NET framework that was originally developed at Microsoft Research Cambridge by Don Syme. In October 2007, the senior vice president of the developer division at Microsoft announced that F# was being officially productized to become a fully supported .NET language and professional developers were hired to create a team of around ten people to build the product version. In September 2008, Microsoft released the first Community Technology Preview (CTP), an official beta release, of the F# distribution . In December 2008, Microsoft announced that the success of this CTP had encouraged them to escalate F# and it is now will now be shipped as one of the core languages in Visual Studio 2010 , alongside C++, C# 4.0 and VB. The F# programming language incorporates many state-of-the-art features from programming language research and ossifies them in an industrial strength implementation that promises to revolutionize interactive, parallel and concurrent programming. Advantages of F# F# is the world's first language to combine all of the following features: Type inference: types are inferred by the compiler and generic definitions are created automatically. Algebraic data types: a succinct way to represent trees. Pattern matching: a comprehensible and efficient way to dissect data structures. Active patterns: pattern matching over foreign data structures. Interactive sessions: as easy to use as Python and Mathematica. High performance JIT compilation to native code: as fast as C#. Rich data structures: lists and arrays built into the language with syntactic support. Functional programming: first-class functions and tail calls. Expressive static type system: finds bugs during compilation and provides machine-verified documentation. Sequence expressions: interrogate huge data sets efficiently. Asynchronous workflows: syntactic support for monadic style concurrent programming with cancellations. Industrial-strength IDE support: multithreaded debugging, and graphical throwback of inferred types and documentation. Commerce friendly design and a viable commercial market. Lets try a short program in C# then F# to understand the differences. Using C#: Create a variable and output the value to the console window: Sample Program. using System;   namespace ConsoleApplication9 {     class Program     {         static void Main(string[] args)         {             var a = 2;             Console.WriteLine(a);             Console.ReadLine();         }     } } A breeze right? 14 Lines of code. We could have condensed it a bit by removing the “using” statment and tossing the namespace. But this is the typical C# program. Using F#: Create a variable and output the value to the console window: To start, open Visual Studio 2010 or Visual Studio 2008. Note: If using VS2008, then please download the SDK first before getting started. If you are using VS2010 then you are already setup and ready to go. So, click File-> New Project –> Other Languages –> Visual F# –> Windows –> F# Application. You will get the screen below. Go ahead and enter a name and click OK. Now, you will notice that the Solution Explorer contains the following: Double click the Program.fs and enter the following information. Hit F5 and it should run successfully. Sample Program. open System let a = 2        Console.WriteLine a As Shown below: Hmm, what? F# did the same thing in 3 lines of code. Show me the interactive evaluation that I keep hearing about. The F# development environment for Visual Studio 2010 provides two different modes of execution for F# code: Batch compilation to a .NET executable or DLL. (This was accomplished above). Interactive evaluation. (Demo is below) The interactive session provides a > prompt, requires a double semicolon ;; identifier at the end of a code snippet to force evaluation, and returns the names (if any) and types of resulting definitions and values. To access the F# prompt, in VS2010 Goto View –> Other Window then F# Interactive. Once you have the interactive window type in the following expression: 2+3;; as shown in the screenshot below: I hope this guide helps you get started with the language, please check out the following books for further information. F# Books for further reading   Foundations of F# Author: Robert Pickering An introduction to functional programming with F#. Including many samples, this book walks through the features of the F# language and libraries, and covers many of the .NET Framework features which can be leveraged with F#.       Functional Programming for the Real World: With Examples in F# and C# Authors: Tomas Petricek and Jon Skeet An introduction to functional programming for existing C# developers written by Tomas Petricek and Jon Skeet. This book explains the core principles using both C# and F#, shows how to use functional ideas when designing .NET applications and presents practical examples such as design of domain specific language, development of multi-core applications and programming of reactive applications.

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• Changing enum in a different class for screen

  - by user2434321

  I'm trying to make a start menu for my game and my code uses Enum's to moniter the screen state. Now i want to change the screenstate declared in the main class, in my Background class Screen screen = new Screen(); is declared in the Game1 class Background(ref screen); This is in the update method for the Background Class KeyboardState keystate = Keyboard.GetState(); switch (screen) { case Screen.Start: if (isPressed && keystate.IsKeyUp(Keys.Up) && keystate.IsKeyUp(Keys.Down) && keystate.IsKeyUp(Keys.Enter)) { isPressed = false; } if (keystate.IsKeyDown(Keys.Down) && isPressed != true) { if (menuState == MenuState.Options) menuState = MenuState.Credits; if (menuState == MenuState.Play) menuState = MenuState.Options; isPressed = true; } if (keystate.IsKeyDown(Keys.Up) && isPressed != true) { if (menuState == MenuState.Options) menuState = MenuState.Play; if (menuState == MenuState.Credits) menuState = MenuState.Options; isPressed = true; } switch (menuState) { case MenuState.Play: arrowRect.X = 450; arrowRect.Y = 220; if (keystate.IsKeyDown(Keys.Enter) && isPressed != true) screen = Screen.Play; break; case MenuState.Options: arrowRect.X = 419; arrowRect.Y = 340; if (keystate.IsKeyDown(Keys.Enter) && isPressed != true) screen = Screen.Options; break; case MenuState.Credits: arrowRect.X = 425; arrowRect.Y = 460; if (keystate.IsKeyDown(Keys.Enter) && isPressed != true) screen = Screen.Credits; break; } break; } } For some reason when I play this and I hit the enter button the Background class's screen is changed but the main class's screen isn't how can i change this? EDIT 1* class Background { private Texture2D background; private Rectangle backgroundRect; private Texture2D arrow; private Rectangle arrowRect; private Screen screen; private MenuState menuState; private bool isPressed = false; public Screen getScreenState(ref Screen screen) { this.screen = screen; return this.screen; } public Background(ref Screen screen) { this.screen = screen; } public void Update() { KeyboardState keystate = Keyboard.GetState(); switch (screen) { case Screen.Start: if (isPressed && keystate.IsKeyUp(Keys.Up) && keystate.IsKeyUp(Keys.Down) && keystate.IsKeyUp(Keys.Enter)) { isPressed = false; } if (keystate.IsKeyDown(Keys.Down) && isPressed != true) { if (menuState == MenuState.Options) menuState = MenuState.Credits; if (menuState == MenuState.Play) menuState = MenuState.Options; isPressed = true; } if (keystate.IsKeyDown(Keys.Up) && isPressed != true) { if (menuState == MenuState.Options) menuState = MenuState.Play; if (menuState == MenuState.Credits) menuState = MenuState.Options; isPressed = true; } switch (menuState) { case MenuState.Play: arrowRect.X = 450; arrowRect.Y = 220; if (keystate.IsKeyDown(Keys.Enter) && isPressed != true) screen = Screen.Play; break; case MenuState.Options: arrowRect.X = 419; arrowRect.Y = 340; if (keystate.IsKeyDown(Keys.Enter) && isPressed != true) screen = Screen.Options; break; case MenuState.Credits: arrowRect.X = 425; arrowRect.Y = 460; if (keystate.IsKeyDown(Keys.Enter) && isPressed != true) screen = Screen.Credits; break; } break; case Screen.Pause: break; case Screen.Over: break; } } public void LoadStartContent(ContentManager Content, GraphicsDeviceManager graphics) { background = Content.Load<Texture2D>("startBackground"); arrow = Content.Load<Texture2D>("arrow"); backgroundRect = new Rectangle(0, 0, graphics.GraphicsDevice.Viewport.Width, graphics.GraphicsDevice.Viewport.Height); arrowRect = new Rectangle(450, 225, arrow.Width, arrow.Height); screen = Screen.Start; } public void LoadPlayContent(ContentManager Content, GraphicsDeviceManager graphics) { background = Content.Load<Texture2D>("Background"); backgroundRect = new Rectangle(0, 0, graphics.GraphicsDevice.Viewport.Width, graphics.GraphicsDevice.Viewport.Height); screen = Screen.Play; } public void LoadOverContent(ContentManager Content, GraphicsDeviceManager graphics) { } public void Draw(SpriteBatch spritebatch) { if (screen == Screen.Start) { spritebatch.Draw(background, backgroundRect, Color.White); spritebatch.Draw(arrow, arrowRect, Color.White); } else spritebatch.Draw(background, backgroundRect, Color.White); } } Thats my background class!

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• Liskov Substitution Principle and the Oft Forgot Third Wheel

  - by Stacy Vicknair

  Liskov Substitution Principle (LSP) is a principle of object oriented programming that many might be familiar with from the SOLID principles mnemonic from Uncle Bob Martin. The principle highlights the relationship between a type and its subtypes, and, according to Wikipedia, is defined by Barbara Liskov and Jeanette Wing as the following principle:   Let be a property provable about objects of type . Then should be provable for objects of type where is a subtype of .   Rectangles gonna rectangulate The iconic example of this principle is illustrated with the relationship between a rectangle and a square. Let’s say we have a class named Rectangle that had a property to set width and a property to set its height. 1: Public Class Rectangle 2: Overridable Property Width As Integer 3: Overridable Property Height As Integer 4: End Class   We all at some point here that inheritance mocks an “IS A” relationship, and by gosh we all know square IS A rectangle. So let’s make a square class that inherits from rectangle. However, squares do maintain the same length on every side, so let’s override and add that behavior. 1: Public Class Square 2: Inherits Rectangle 3:  4: Private _sideLength As Integer 5:  6: Public Overrides Property Width As Integer 7: Get 8: Return _sideLength 9: End Get 10: Set(value As Integer) 11: _sideLength = value 12: End Set 13: End Property 14:  15: Public Overrides Property Height As Integer 16: Get 17: Return _sideLength 18: End Get 19: Set(value As Integer) 20: _sideLength = value 21: End Set 22: End Property 23: End Class   Now, say we had the following test: 1: Public Sub SetHeight_DoesNotAffectWidth(rectangle As Rectangle) 2: 'arrange 3: Dim expectedWidth = 4 4: rectangle.Width = 4 5:  6: 'act 7: rectangle.Height = 7 8:  9: 'assert 10: Assert.AreEqual(expectedWidth, rectangle.Width) 11: End Sub   If we pass in a rectangle, this test passes just fine. What if we pass in a square?   This is where we see the violation of Liskov’s Principle! A square might "IS A” to a rectangle, but we have differing expectations on how a rectangle should function than how a square should! Great expectations Here’s where we pat ourselves on the back and take a victory lap around the office and tell everyone about how we understand LSP like a boss. And all is good… until we start trying to apply it to our work. If I can’t even change functionality on a simple setter without breaking the expectations on a parent class, what can I do with subtyping? Did Liskov just tell me to never touch subtyping again? The short answer: NO, SHE DIDN’T. When I first learned LSP, and from those I’ve talked with as well, I overlooked a very important but not appropriately stressed quality of the principle: our expectations. Our inclination is to want a logical catch-all, where we can easily apply this principle and wipe our hands, drop the mic and exit stage left. That’s not the case because in every different programming scenario, our expectations of the parent class or type will be different. We have to set reasonable expectations on the behaviors that we expect out of the parent, then make sure that those expectations are met by the child. Any expectations not explicitly expected of the parent aren’t expected of the child either, and don’t register as a violation of LSP that prevents implementation. You can see the flexibility mentioned in the Wikipedia article itself: A typical example that violates LSP is a Square class that derives from a Rectangle class, assuming getter and setter methods exist for both width and height. The Square class always assumes that the width is equal with the height. If a Square object is used in a context where a Rectangle is expected, unexpected behavior may occur because the dimensions of a Square cannot (or rather should not) be modified independently. This problem cannot be easily fixed: if we can modify the setter methods in the Square class so that they preserve the Square invariant (i.e., keep the dimensions equal), then these methods will weaken (violate) the postconditions for the Rectangle setters, which state that dimensions can be modified independently. Violations of LSP, like this one, may or may not be a problem in practice, depending on the postconditions or invariants that are actually expected by the code that uses classes violating LSP. Mutability is a key issue here. If Square and Rectangle had only getter methods (i.e., they were immutable objects), then no violation of LSP could occur. What this means is that the above situation with a rectangle and a square can be acceptable if we do not have the expectation for width to leave height unaffected, or vice-versa, in our application. Conclusion – the oft forgot third wheel Liskov Substitution Principle is meant to act as a guidance and warn us against unexpected behaviors. Objects can be stateful and as a result we can end up with unexpected situations if we don’t code carefully. Specifically when subclassing, make sure that the subclass meets the expectations held to its parent. Don’t let LSP think you cannot deviate from the behaviors of the parent, but understand that LSP is meant to highlight the importance of not only the parent and the child class, but also of the expectations WE set for the parent class and the necessity of meeting those expectations in order to help prevent sticky situations.   Code examples, in both VB and C# Technorati Tags: LSV,Liskov Substitution Principle,Uncle Bob,Robert Martin,Barbara Liskov,Liskov

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