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• Software Testing Humor

  - by mbcrump

  I usually don’t share these kind of things unless it really makes me laugh. At least, I can provide a link to a free eBook on the Pablo’s S.O.L.I.D principles eBook. S.O.L.I.D. is a collection of best-practice object-oriented design principles that you can apply to your design to accomplish various desirable goals like loose-coupling, higher maintainability, intuitive location of interesting code, etc You may also want to check out the Pablo’s 31 Days of Refactoring eBook as well.

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• Count Email Address Domains

  - by BRADINO

  A quick tidbit I came up with today to count email addresses in a mysql database table grouping them by domain. So say for example you have a large list of subscribers and you want to see the breakdown of people who use Hotmail, Yahoo, Gmail, etc. SELECT COUNT( SUBSTRING_INDEX( `email` , '@', -1 ) ) AS `count` , SUBSTRING_INDEX( `email` , '@', -1 ) AS `domain` FROM `subscribers` WHERE `email` != '' GROUP BY `domain` ORDER BY `count` DESC This sql statement assumes that the table is called 'subscribers' and the column containing the email addresses is 'email'. Change these two values to match your table name and email address column name. mysql count email mysql count domain mysql split email mysql split domain

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• Pyro Jam Can Is a DIY Mini Ruben’s Tube

  - by Jason Fitzpatrick

  Earlier this year we showed you how to make a full-size Ruben’s Tube; now make a tiny single-column fire speaker with the Pyro Jam Can. Instructables’ user Patrick needed a simple device to enter into an Instuctables contest centered on fire-themed projects. His contribution, seen in the video above, is a single-column Ruben’s Tube (for the unfamiliar, a Ruben’s Tube is a device through which sound and flammable gas are passed; the resulting flame is modulated by the frequency of the sound). If your next party wouldn’t be the same without a sound system that pumps bass beats and fire, you know where to get started. The Pyro Jam Can [via Hack A Day] Use Amazon’s Barcode Scanner to Easily Buy Anything from Your Phone How To Migrate Windows 7 to a Solid State Drive Follow How-To Geek on Google+

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• Podcast Show Notes: The Red Room Interview &ndash; Part 1

  - by Bob Rhubart

    The latest OTN Arch2Arch podcast is Part 1 of a three-part series featuring a discussion of a broad range of SOA  issues with three members of the small army of contributors to The Red Room Blog, now part of the OJam.biz site, the Australia-New Zealand outpost of the global Oracle community. The panelists for this program are: Sean Boiling - Sales Consulting Manager for Oracle Fusion Middleware LinkedIn | Twitter | Blog Richard Ward - SOA Channel Development Manager at Oracle LinkedIn | Blog Mervin Chiang - Consulting Principal at Leonardo Consulting LinkedIn | Twitter | Blog (You can also follow the Red Room itself on Twitter: @OracleRedRoom.) The genesis of this interview goes back to 2009, and the original Red Room blog, on which Sean, Richard, Mervin, and other Red Roomers published a 10-part series of posts that, taken together, form a kind of SOA best-practices guide, presented in an irreverent style that is rare in a lot of technical writing. It was on the basis of their expertise and irreverence that I wanted to get a few of the Red Room bloggers on an Arch2Arch podcast.  Easier said than done. Trying to schedule a group interview with very busy people on the other side of world (they’re actually 15 hours in the future, relative to my location) is not a simple process. The conversations about getting some of the Red Room people on the program began in the summer of 2009. The interview finally happened at 5:30 PM EDT on Tuesday March 30, 2010, which for the panelists, located in Australia, was 8:30 AM on Wednesday March 31, 2010. I was waiting for dinner, and Sean, Richard, and Mervin were waiting for breakfast. But the call went off without a hitch, and the panelists carried on a great discussion of SOA issues. Listen to Part 1 Many thanks to Gareth Llewellyn for his help in putting this together. SOA Best Practices Here’s a complete list of the posts in the original 10-part Red Room series: SOA is Dead. Long Live SOA by Sean Boiling Are you doing SOP’s instead of SOA? by Saul Cunningham All The President's SOA by Sean Boiling SOA – Pay Now or Pay Dearly by Richard Ward SOA where are the skills? by Richard Ward Project Management Pitfalls within SOA by Anton Gouws Viewing SOA as a project instead of an architecture by Saul Cunningham Kiss and Tell by Sean Boiling Failure to implement and adhere to SOA Governance by Mervin Chiang Ten Out Of Ten by Sean Boiling Parts 2 of the Red Room Interview will be available next week, followed by Part 3, so stay tuned: RSS Change in the Wind Beginning with next week’s program, the OTN Arch2Arch Podcast will be rechristened as the OTN ArchBeat Podcast, to better align with this blog. The transformation will be painless – you won’t feel a thing.   del.icio.us Tags: otn,oracle,Archbeat,Arch2Arch,soa,service oriented architecture,podcast Technorati Tags: otn,oracle,Archbeat,Arch2Arch,soa,service oriented architecture,podcast

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• Don&rsquo;t Forget! In-Memory Databases are Hot

  - by andrewbrust

  If you’re left scratching your head over SAP’s intention to acquire Sybase for almost $6 million, you’re not alone.  Despite Sybase’s 1990s reign as the supreme database standard in certain sectors (including Wall Street), the company’s flagship product has certainly fallen from grace.  Why would SAP pay a greater than 50% premium over Sybase’s closing price on the day of the announcement just to acquire a relational database which is firmly stuck in maintenance mode? Well there’s more to Sybase than the relational database product.  Take, for example, its mobile application platform.  It hit Gartner’s “Leaders’ Quadrant” in January of last year, and SAP needs a good mobile play.  Beyond the platform itself, Sybase has a slew of mobile services; click this link to look them over. There’s a second major asset that Sybase has though, and I wonder if it figured prominently into SAP’s bid: Sybase IQ.  Sybase IQ is a columnar database.  Columnar databases place values from a given database column contiguously, unlike conventional relational databases, which store all of a row’s data in close proximity.  Storing column values together works well in aggregation reporting scenarios, because the figures to be aggregated can be scanned in one efficient step.  It also makes for high rates of compression because values from a single column tend to be close to each other in magnitude and may contain long sequences of repeating values.  Highly compressible databases use much less disk storage and can be largely or wholly loaded into memory, resulting in lighting fast query performance.  For an ERP company like SAP, with its own legacy BI platform (SAP BW) and the entire range of Business Objects and Crystal Reports BI products (which it acquired in 2007) query performance is extremely important. And it’s a competitive necessity too.  QlikTech has built an entire company on a columnar, in-memory BI product (QlikView).  So too has startup company Vertica.  IBM’s TM1 product has been doing in-memory OLAP for years.  And guess who else has the in-memory religion?  Microsoft does, in the form of its new PowerPivot product.  I expect the technology in PowerPivot to become strategic to the full-blown SQL Server Analysis Services product and the entire Microsoft BI stack.  I sure don’t blame SAP for jumping on the in-memory bandwagon, if indeed the Sybase acquisition is, at least in part, motivated by that. It will be interesting to watch and see what SAP does with Sybase’s product line-up (assuming the acquisition closes), including the core database, the mobile platform, IQ, and even tools like PowerBuilder.  It is also fascinating to watch columnar’s encroachment on relational.  Perhaps this acquisition will be columnar’s tipping point and people will no longer see it as a fad.  Are you listening Larry Ellison?

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• DonXml does WCF in NYC

  - by gsusx

  Tomorrow is WCF day in New York city!!!!! My good friend and Tellago's CTO Don Demsak will be doing a session WCF Data and RIA Services at the WCF fire-starter event to be hosted at the Microsoft offices in New York city. Don has a encyclopedic knowledge of both technologies and will be sharing lots of best practices learned from applying these technologies in large service oriented environments. In addition to Don, my crazy Cuban friend Miguel Castro will also be presenting three sessions at the...(read more)

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• jQuery Datatable in MVC &hellip; extended.

  - by Steve Clements

  There are a million plugins for jQuery and when a web forms developer like myself works in MVC making use of them is par-for-the-course!  MVC is the way now, web forms are but a memory!! Grids / tables are my focus at the moment.  I don’t want to get in to righting reems of css and html, but it’s not acceptable to simply dump a table on the screen, functionality like sorting, paging, fixed header and perhaps filtering are expected behaviour.  What isn’t always required though is the massive functionality like editing etc you get with many grid plugins out there. You potentially spend a long time getting everything hooked together when you just don’t need it. That is where the jQuery DataTable plugin comes in.  It doesn’t have editing “out of the box” (you can add other plugins as you require to achieve such functionality). What it does though is very nicely format a table (and integrate with jQuery UI) without needing to hook up and Async actions etc.  Take a look here… http://www.datatables.net I did in the first instance start looking at the Telerik MVC grid control – I’m a fan of Telerik controls and if you are developing an in-house of open source app you get the MVC stuff for free…nice!  Their grid however is far more than I require.  Note: Using Telerik MVC controls with your own jQuery and jQuery UI does come with some hurdles, mainly to do with the order in which all your jQuery is executing – I won’t cover that here though – mainly because I don’t have a clear answer on the best way to solve it! One nice thing about the dataTable above is how easy it is to extend http://www.datatables.net/examples/plug-ins/plugin_api.html and there are some nifty examples on the site already… I however have a requirement that wasn’t on the site … I need a grid at the bottom of the page that will size automatically to the bottom of the page and be scrollable if required within its own space i.e. everything above the grid didn’t scroll as well.  Now a CSS master may have a great solution to this … I’m not that master and so didn’t! The content above the grid can vary so any kind of fixed positioning is out. So I wrote a little extension for the DataTable, hooked that up to the document.ready event and window.resize event. Initialising my dataTable ( s )… $(document).ready(function () {   var dTable = $(".tdata").dataTable({ "bPaginate": false, "bLengthChange": false, "bFilter": true, "bSort": true, "bInfo": false, "bAutoWidth": true, "sScrollY": "400px" });   My extension to the API to give me the resizing….   // ********************************************************************** // jQuery dataTable API extension to resize grid and adjust column sizes // $.fn.dataTableExt.oApi.fnSetHeightToBottom = function (oSettings) { var id = oSettings.nTable.id; var dt = $("#" + id); var top = dt.position().top; var winHeight = $(document).height(); var remain = (winHeight - top) - 83; dt.parent().attr("style", "overflow-x: auto; overflow-y: auto; height: " + remain + "px;"); this.fnAdjustColumnSizing(); } This is very much is debug mode, so pretty verbose at the moment – I’ll tidy that up later! You can see the last call is a call to an existing method, as the columns are fixed and that normally involves so CSS voodoo, a call to adjust those sizes is required. Just above is the style that the dataTable gives the grid wrapper div, I got that from some firebug action and stick in my new height. The –83 is to give me the space at the bottom i require for fixed footer!   Finally I hook that up to the load and window resize.  I’m actually using jQuery UI tabs as well, so I’ve got that in the open event of the tabs.   $(document).ready(function () { var oTable; $("#tabs").tabs({ "show": function (event, ui) { oTable = $('div.dataTables_scrollBody>table.tdata', ui.panel).dataTable(); if (oTable.length > 0) { oTable.fnSetHeightToBottom(); } } }); $(window).bind("resize", function () { oTable.fnSetHeightToBottom(); }); }); And that all there is too it.  Testament to the wonders of jQuery and the immense community surrounding it – to which I am extremely grateful. I’ve also hooked up some custom column filtering on the grid – pretty normal stuff though – you can get what you need for that from their website.  I do hide the out of the box filter input as I wanted column specific, you need filtering turned on when initialising to get it to work and that input come with it!  Tip: fnFilter is the method you want.  With column index as a param – I used data tags to simply that one.

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• Microsoft F#

  - by Aamir Hasan

  F# brings you type safe, succinct, efficient and expressive functional programming language on the .NET platform. It is a simple and pragmatic language, and has particular strengths in data-oriented programming, parallel I/O programming, parallel CPU programming, scripting and algorithmic development. F# cannot solve any problem C# could. F# is a functional language, statically typed. F# is a functional language that supports O-O-Programming References:http://msdn.microsoft.com/en-us/fsharp/cc835246.aspx http://research.microsoft.com/en-us/um/cambridge/projects/fsharp/

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• SQL SERVER – Select and Delete Duplicate Records – SQL in Sixty Seconds #036 – Video

  - by pinaldave

  Developers often face situations when they find their column have duplicate records and they want to delete it. A good developer will never delete any data without observing it and making sure that what is being deleted is the absolutely fine to delete. Before deleting duplicate data, one should select it and see if the data is really duplicate. In this video we are demonstrating two scripts – 1) selects duplicate records 2) deletes duplicate records. We are assuming that the table has a unique incremental id. Additionally, we are assuming that in the case of the duplicate records we would like to keep the latest record. If there is really a business need to keep unique records, one should consider to create a unique index on the column. Unique index will prevent users entering duplicate data into the table from the beginning. This should be the best solution. However, deleting duplicate data is also a very valid request. If user realizes that they need to keep only unique records in the column and if they are willing to create unique constraint, the very first requirement of creating a unique constraint is to delete the duplicate records. Let us see how to connect the values in Sixty Seconds: Here is the script which is used in the video. USE tempdb GO CREATE TABLE TestTable (ID INT, NameCol VARCHAR(100)) GO INSERT INTO TestTable (ID, NameCol) SELECT 1, 'First' UNION ALL SELECT 2, 'Second' UNION ALL SELECT 3, 'Second' UNION ALL SELECT 4, 'Second' UNION ALL SELECT 5, 'Second' UNION ALL SELECT 6, 'Third' GO -- Selecting Data SELECT * FROM TestTable GO -- Detecting Duplicate SELECT NameCol, COUNT(*) TotalCount FROM TestTable GROUP BY NameCol HAVING COUNT(*) > 1 ORDER BY COUNT(*) DESC GO -- Deleting Duplicate DELETE FROM TestTable WHERE ID NOT IN ( SELECT MAX(ID) FROM TestTable GROUP BY NameCol) GO -- Selecting Data SELECT * FROM TestTable GO DROP TABLE TestTable GO Related Tips in SQL in Sixty Seconds: SQL SERVER – Delete Duplicate Records – Rows SQL SERVER – Count Duplicate Records – Rows SQL SERVER – 2005 – 2008 – Delete Duplicate Rows Delete Duplicate Records – Rows – Readers Contribution Unique Nonclustered Index Creation with IGNORE_DUP_KEY = ON – A Transactional Behavior What would you like to see in the next SQL in Sixty Seconds video? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video Tagged: Excel

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• links for 2010-04-27

  - by Bob Rhubart

  @oracletechnet: Oracle Technology Network Newsletters Revisited "You may find this hard to believe, but some analysts contend that email newsletters are still among the most preferred methods of "information awareness" by developers today. And in our experience, the numbers back it up: subscriptions to Oracle Technology Network newsletters grow organically by 15% every year, even after you take continual list cleanup into account. " -- Justin Kestelyn (tags: oracle otn newsletters developers architects) Sylvain Duloutre: Directory Services as a Web Service Sylvain Duloutre shares a WSDL file he created to deal with issues involved in XML binding generation. (tags: oracle sun wsdl webservices DSEE netbeans jdeveloper) Nick Wooler: Iron-Clad Cloud: Secure Cloud Computing "One solution to the security problem with cloud services can be overcome using Service Oriented Security. The Oracle approach to using Service Oriented Security allows developers to pull from a centralized, authoritative source of identity services. This allows developers to build security into every application from the inside-out. This is critical to ensuring this is done in a standardized manner and most importantly it allows developers to develop without being security experts." -- Nick Wooler (tags: oracle sun security cloud saas) Andy Mulholland: A week of visits; Cisco, HP, Oracle, SAP and VMware (in alphabetical order!) "I now am considering that we should be thinking about ‘clouds’ in virtual way, by which I mean that a succession of virtual ‘clouds’ will need to exist, each possessing specific characteristics that suit certain types of services. Really it’s no different to what we see with servers today. Adding a hypervisor to a server adds new flexibility, but creating a virtualised environment means much more. What I suspect will happen is that we will start to use vendor specific approaches to building what I will term a physical cloud solution using their technology and approach to supporting a specific objective, but with time we will find these physical clouds will interoperate as a fully virtualised cloud environment." -- Andy Mulholland (tags: entarch enterprisearchitecture cloudcomputing virtualization) @fteter: Highlights From The Bright Lights - Tuesday #c10 Oracle Ace Director Floyd Teter of JPL with one last wrap-up of Collaborate 10. (tags: oracle otn collaborate2010 las vegas) Rittman Mead India – Call for very good Oracle BI Developers/Architects "Now that we have an office in India and if you are interested in joining us, do drop us a line at [email protected], and we will be glad to have technical discussions with you. If you are also an Oracle BI, DW or EPM customer looking for help on projects in the Asia-Pacific region, again we’ll be pleased to hear from you and to let you know how we can help." -- Venkatakrishnan J (tags: otn oracle jobs india developers architects software)

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• Connected Systems (SOA) QuickStart Materials

  - by Rajesh Charagandla

  The Connected Systems (SOA) QuickStart includes a comprehensive set of technical content including presentations, whitepapers and demos that are designed to present to customers to assess the current state of their Service Oriented Architecture (SOA) and integration capabilities and understand how a Microsoft solution built using products such as BizTalk Server can help address their SOA and integration needs. This QuickStart includes delivery materials, self-paced training materials and supplementary materials.   Download from the Material from here

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• How Fusion Middleware Built the Fusion User Experience

  See how you can leverage the entire Fusion Middleware stack to create a compelling user experience, just like Oracle's Applications User Experience team did during the design of Fusion Applications. Learn about key Fusion Middleware components that comprise Oracle's new end-to-end user experience platform in Fusion Applications. Hear about the role of components such as Application Development Framework (ADF), WebCenter, Metadata Services (MDS), Service-Oriented Architecture (SOA), and design patterns.

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• What type of interview questions should you ask for "legacy" programmers?

  - by Marcus Swope

  We have recently been receiving lots of applicants for our open developer positions from people who I like to refer to as "legacy" programmers. I don't like the term "old" because it seems a little prejudiced (especially to HR!) and it doesn't accurately reflect what I mean. We are a company that does primarily .NET development using TDD in an Agile environment, we use Git as a source control system, we make heavy use of OSS tools and projects and we contribute to them as well, we have a strong bias towards adhering to strong Object-Oriented principles, SOLID, etc, etc, etc... Now, the normal list of questions that we ask doesn't really seem to apply to applicants that are fresh out of school, nor does it seem to apply to these "legacy" programmers. Here is how I (loosely) define a "legacy" programmer. Spent a significant amount of their career working almost exclusively with Assembly/Machine Languages. Primary accomplishments include work done with TANDEM systems. Has extensive experience with technologies like FoxPro and ColdFusion It's not that we somehow think that what we do is "better" than what they do, on the contrary, we respect these types of applicants and we are scared that we may be missing a good candidate. It is just very difficult to get a good read on someone who is essentially speaking a different language than you. To someone like this, it seems a little strange to ask a question like: What is the difference between an abstract class and an interface? Because, I would think that they would almost never know the answer or even what I'm talking about. However, I don't want to eliminate someone who could be a very good candidate in their own right and could be able to eventually learn the stuff that we do. But, I also don't want to just ask a bunch of behavioral questions, because I want to know about their technical background as well. Am I being too naive? Should "legacy" programmers like this already know about things like TDD, source control strategies, and best practices for object-oriented programming? If not, what questions should we ask to get a good representation about whether or not they are still able to learn them and be able to keep up in our fast-paced environment? EDIT: I'm not concerned with whether or not applicants that meet these criteria are in general capable or incapable, as I have already stated that I believe that they can be 100% capable. I am more interested in figuring out how to evaluate their talents, as I am having a hard time figuring out how to determine if they are an A+ "legacy" programmer or if they are a D- "legacy" programmer. I've worked with both.

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• Achieving Zero Downtime Deployment

  - by MattW

  I am trying to achieve zero downtime deployments so I can deploy less during off hours and more during "slower" hours - or anytime, in theory. My current setup, somewhat simplified: Web Server A (.NET App) Web Server B (.NET App) Database Server (SQL Server) My current deployment process: "Stop" the sites on both Web Server A and B Upgrade the database schema for the version of the app being deployed Update Web Server A Update Web Server B Bring everything back online Current Problem This leads to a small amount of downtime each month - about 30 mins. I do this during off hours, so it isn't a huge problem - but it is something I'd like to get away from. Also - there is no way to really go 'back'. I don't generally make rollback DB scripts - only upgrade scripts. Leveraging The Load Balancer I'd love to be able to upgrade one Web Server at a time. Take Web Server A out of the load balancer, upgrade it, put it back online, then repeat for Web Server B. The problem is the database. Each version of my software will need to execute against a different version of the database - so I am sort of "stuck". Possible Solution A current solution I am considering is adopting the following rules: Never delete a database table. Never delete a database column. Never rename a database column. Never reorder a column. Every stored procedure must be versioned. Meaning - 'spFindAllThings' will become 'spFindAllThings_2' when it is edited. Then it becomes 'spFindAllThings_3' when edited again. Same rule applies to views. While, this seems a bit extreme - I think it solves the problem. Each version of the application will be hitting the DB in a non breaking way. The code expects certain results from the views/stored procedures - and this keeps that 'contract' valid. The problem is - it just seeps sloppy. I know I can clean up old stored procedures after the app is deployed for awhile, but it just feels dirty. Also - it depends on all of the developers following these rule, which will mostly happen, but I imagine someone will make a mistake. Finally - My Question Is this sloppy or hacky? Is anybody else doing it this way? How are other people solving this problem?

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• Steve Jobs's Touch Is What Ubuntu's Missing: Rich Jaroslovsky

  <b>Bloomberg:</b> "If you're put off by Steve Jobs's control-freakdom and Microsoft's long history of buggy bloatware, you might want to spend some time with Dell's line of laptops running Ubuntu, the free, consumer-oriented version of the open-source Linux operating system."

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• Static class vs Singleton class in C# [closed]

  - by Floradu88

  Possible Duplicate: What is the difference between all-static-methods and applying a singleton pattern? I need to make a decision for a project I'm working of whether to use static or singleton. After reading an article like this I am inclined to use singleton. What is better to use static class or singleton? Edit 1 : Client Server Desktop Application. Please provide code oriented solutions.

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• ROA on top of SOA

  - by Vaibhav Pujari

  I already have a stable Service Oriented Architecture for my application which exposes services as API calls. (the verbs) Now, I need to build a Resource Oriented Architecture to expose a RESTful API to interact with the application objects. (the nouns) What are the best practices to reuse the existing services: - without any persistence inside my new code. - without putting unnecessary logic into the REST layer i.e. it should ideally just leverage the services provided by SOA API. I want this layer to be as thin as possible. - without modifying the existing SOA API - allow easy extension of the REST API i.e. it should be easy to add more resources without changing the (yet to be written) core code. (I want to make resource names and their associated actions configurable so more contributors can easily add resources without a need to understand my module) Any advices/suggestions how to achieve this? Edit: Adding more info My Stack: My existing stacks is in Java. But since I plan to just use the services, I don't think that should affect the design of new REST code. I am planning to implement the new REST code in PHP. How well the services map to resources? Some services are mapped well i.e. there are services for creating, updating application objects. But for other application objects, there are no direct services available. More importantly, there are actions beyond just create, update etc. that apply to application objects. And I would like to provide some way for these actions to be exposed through REST. Since these are verbs, how do I deal with them? Where exactly I need help? I would appreciate any help towards high level design to accomplish the task along-with making the framework extendible. For instance, tomorrow there are some new services added to my SOA layer, I want to make sure it is easy for a fresh developer to write a REST call by simply registering a new resource (in a config file/db) and write code for connecting it with SOA calls. Just like plugin.

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• YouTube + You

  YouTube is an extremely team-oriented, creative workplace where every single employee has a voice in the choices we make and the features we implement. We work together in...

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• Joins in single-table queries

  - by Rob Farley

  Tables are only metadata. They don’t store data. I’ve written something about this before, but I want to take a viewpoint of this idea around the topic of joins, especially since it’s the topic for T-SQL Tuesday this month. Hosted this time by Sebastian Meine (@sqlity), who has a whole series on joins this month. Good for him – it’s a great topic. In that last post I discussed the fact that we write queries against tables, but that the engine turns it into a plan against indexes. My point wasn’t simply that a table is actually just a Clustered Index (or heap, which I consider just a special type of index), but that data access always happens against indexes – never tables – and we should be thinking about the indexes (specifically the non-clustered ones) when we write our queries. I described the scenario of looking up phone numbers, and how it never really occurs to us that there is a master list of phone numbers, because we think in terms of the useful non-clustered indexes that the phone companies provide us, but anyway – that’s not the point of this post. So a table is metadata. It stores information about the names of columns and their data types. Nullability, default values, constraints, triggers – these are all things that define the table, but the data isn’t stored in the table. The data that a table describes is stored in a heap or clustered index, but it goes further than this. All the useful data is going to live in non-clustered indexes. Remember this. It’s important. Stop thinking about tables, and start thinking about indexes. So let’s think about tables as indexes. This applies even in a world created by someone else, who doesn’t have the best indexes in mind for you. I’m sure you don’t need me to explain Covering Index bit – the fact that if you don’t have sufficient columns “included” in your index, your query plan will either have to do a Lookup, or else it’ll give up using your index and use one that does have everything it needs (even if that means scanning it). If you haven’t seen that before, drop me a line and I’ll run through it with you. Or go and read a post I did a long while ago about the maths involved in that decision. So – what I’m going to tell you is that a Lookup is a join. When I run SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 285; against the AdventureWorks2012 get the following plan: I’m sure you can see the join. Don’t look in the query, it’s not there. But you should be able to see the join in the plan. It’s an Inner Join, implemented by a Nested Loop. It’s pulling data in from the Index Seek, and joining that to the results of a Key Lookup. It clearly is – the QO wouldn’t call it that if it wasn’t really one. It behaves exactly like any other Nested Loop (Inner Join) operator, pulling rows from one side and putting a request in from the other. You wouldn’t have a problem accepting it as a join if the query were slightly different, such as SELECT sod.OrderQty FROM Sales.SalesOrderHeader AS soh JOIN Sales.SalesOrderDetail as sod on sod.SalesOrderID = soh.SalesOrderID WHERE soh.SalesPersonID = 285; Amazingly similar, of course. This one is an explicit join, the first example was just as much a join, even thought you didn’t actually ask for one. You need to consider this when you’re thinking about your queries. But it gets more interesting. Consider this query: SELECT SalesOrderID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276 AND CustomerID = 29522; It doesn’t look like there’s a join here either, but look at the plan. That’s not some Lookup in action – that’s a proper Merge Join. The Query Optimizer has worked out that it can get the data it needs by looking in two separate indexes and then doing a Merge Join on the data that it gets. Both indexes used are ordered by the column that’s indexed (one on SalesPersonID, one on CustomerID), and then by the CIX key SalesOrderID. Just like when you seek in the phone book to Farley, the Farleys you have are ordered by FirstName, these seek operations return the data ordered by the next field. This order is SalesOrderID, even though you didn’t explicitly put that column in the index definition. The result is two datasets that are ordered by SalesOrderID, making them very mergeable. Another example is the simple query SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276; This one prefers a Hash Match to a standard lookup even! This isn’t just ordinary index intersection, this is something else again! Just like before, we could imagine it better with two whole tables, but we shouldn’t try to distinguish between joining two tables and joining two indexes. The Query Optimizer can see (using basic maths) that it’s worth doing these particular operations using these two less-than-ideal indexes (because of course, the best indexese would be on both columns – a composite such as (SalesPersonID, CustomerID – and it would have the SalesOrderID column as part of it as the CIX key still). You need to think like this too. Not in terms of excusing single-column indexes like the ones in AdventureWorks2012, but in terms of having a picture about how you’d like your queries to run. If you start to think about what data you need, where it’s coming from, and how it’s going to be used, then you will almost certainly write better queries. …and yes, this would include when you’re dealing with regular joins across multiples, not just against joins within single table queries.

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• Search and Browse Database Objects with Oracle SQL Developer

  - by thatjeffsmith

  I was tempted to throw in another Dora the Explorer Map reference here, but I came to my senses.Having trouble finding something? Maybe you’re just getting older? I know I am. But still, it’d be nice if my favorite database tool could help me out a bit. Hmmm, what’s this ‘Find Database Object‘ thing over here…sounds like a search mechanism of some sort? You can access this panel from the ‘View‘ menu. It’s a good bit down the screen, so I don’t blame you if you haven’t seen it before. It makes finding ‘stuff’ in your database so much easier. Let’s say I want to find my ‘beer’ objects. I simply need to type my search string and the context (in this case I want it to search EVERYTHING), and hit enter. The search results are listed below and clicking on an object automatically opens it! I know it seems very simple, but I get asked this question a LOT. It will even search through your PL/SQL code! Finding too much? Be sure to toggle off the ‘%’ wildcard check box before doing a search. Working on a Project? I bet you use common column names, or codes, throughout your tables. You could take advantage of this knowledge and use the Find Database Object panel as a substitute connection tree or schema browser. Working on your HR project and want to look at your employee objects? Do a column search for your column ID/key. Sometimes thinking outside the box actually works! Don’t be afraid to tackle a problem from a weird angle, or re-purpose your tools. I do it all the time And I drive the developers nuts trying to do things with the tools they were never designed to do. But I digress. Back to your coding!

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• Django as Python extension?

  - by NoobDev4iPhone

  I come from php community and just started learning Python. I have to create server-side scripts that manipulate databases, files, and send emails. Some of it I found hard to do in python, comparing to php, like sending emails and querying databases. Where in php you have functions like mysql_query(), or email(), in python you have to write whole bunch of code. Recently I found Django, and my question is: is it a good framework for network-oriented scripts, instead of using it as a web-framework?

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• DBCC MEMUSAGE in 2005/8 ?

  - by steveh99999

  I used to like using undocumented command DBCC MEMUSAGE in SQL 2000 to see which tables were using space in SQL data cache. In SQL 2005, this command is not longer present. Instead a DMV – sys.dm_os_buffer_descriptors – can be used to display data cache contents,  but this doesn’t quite give you the same output as DBCC MEMUSAGE. I’m also aware that you can use Quest’s spotlight tool to view a summary of data cache contents. Using  this post by Umachandar Jayachandran  of Microsoft, I was able to create the following equivalent for SQL 2005/8. I’ve wrapped Umachandar’s original query in a CTE to produce summary information :- ;WITH memusage_CTE AS (SELECT bd.database_id, bd.file_id, bd.page_id, bd.page_type , COALESCE(p1.object_id, p2.object_id) AS object_id , COALESCE(p1.index_id, p2.index_id) AS index_id , bd.row_count, bd.free_space_in_bytes, CONVERT(TINYINT,bd.is_modified) AS 'DirtyPage' FROM sys.dm_os_buffer_descriptors AS bd JOIN sys.allocation_units AS au ON au.allocation_unit_id = bd.allocation_unit_id OUTER APPLY ( SELECT TOP(1) p.object_id, p.index_id FROM sys.partitions AS p WHERE p.hobt_id = au.container_id AND au.type IN (1, 3) ) AS p1 OUTER APPLY ( SELECT TOP(1) p.object_id, p.index_id FROM sys.partitions AS p WHERE p.partition_id = au.container_id AND au.type = 2 ) AS p2 WHERE  bd.database_id = DB_ID() AND bd.page_type IN ('DATA_PAGE', 'INDEX_PAGE') ) SELECT TOP 20 DB_NAME(database_id) AS 'Database',OBJECT_NAME(object_id,database_id) AS 'Table Name', index_id,COUNT(*) AS 'Pages in Cache', SUM(dirtyPage) AS 'Dirty Pages' FROM memusage_CTE GROUP BY database_id, object_id, index_id ORDER BY COUNT(*) DESC I’m not 100% happy with the results of the above query however… I’ve noticed that on a busy BizTalk messageBox database  it will return information on pages that contain GHOST rows – . ie where data has already been deleted but has yet to be cleaned-up by a background process – I’m need to investigate further why cache on this server apparently contains so much GHOST data… For more information on the background ghost cleanup process, see this article by Paul Randall. However, I think the results of this query should still be of interest to a DBA. I have another post to come shortly regarding an example I encountered where this information proved useful to me… I notice in SQL 2008, sys.dm_os_buffer_descriptors gained an extra column – numa_mode – I’m interested to see how this is populated and how useful this column can be on a NUMA-enabled system. I’m assuming in theory you could use this column to help analyse how your tables are spread across Numa-enabled data-cache ?

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• Repeat row headers after Page Break

  - by klaus.fabian

  The lead developer of the FO engine send me by chance an email about a REALLY nice feature I did not know about. Did you ever encounter a long table with merged cells, where the merged cell went on to the next page? While column headers are by default repeated on the next page, row headers are not. Tables with group-left column and pivot tables are prime examples where this problem occurs. I have seen reports where merged cells could go over multiple pages and you would need to back to find the row header on previous pages. The BI Publisher RTF templates have a special tag you can added to a merged cell to repeat the contents after each page break. You just need to add the following (wordy) tag to the next merged table cell: true Example: 2nd page of report before adding the tag 2nd page of report after adding the tag. Thought you might want to know. Klaus

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• What are algorithmic paradigms?

  - by Vaibhav Agarwal

  We generally talk about paradigms of programming as functional, procedural, object oriented, imperative etc but what should I reply when I am asked the paradigms of algorithms? For example are Travelling Salesman Problem, Dijkstra Shortest Path Algorithm, Euclid GCD Algorithm, Binary search, Kruskal's Minimum Spanning Tree, Tower of Hanoi paradigms of algorithms? Should I answer the data structures I would use to design these algorithms?

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• SQL SERVER – Simple Explanation and Puzzle with SOUNDEX Function and DIFFERENCE Function

  - by pinaldave

  Earlier this week I asked a question where I asked how to Swap Values of the column without using CASE Statement. Read here: A Puzzle – Swap Value of Column Without Case Statement,there were more than 50 solutions proposed in the comment. There were many creative solutions. I have mentioned my personal favorite (different ones) here: Solution of Puzzle – Swap Value of Column Without Case Statement. However, I received lots of questions regarding one of the Solution by SIJIN KUMAR V P. He has used the function SOUNDEX in his solution. The request was to explain how SOUNDEX and DIFFERENCE works. Well, there are pretty decent documentations provided over here SOUNDEX function and DIFFERENCE over on MSDN and if I attempt to explain this function I will end up writing the same details which are available on MSDN. Instead of writing theory, we will try to learn this function by using a couple of simple puzzles. You try to solve the puzzles using the MSDN and see if you can learn something very quickly. In simple words - SOUNDEX converts an alphanumeric string to a four-character code to find similar-sounding words or names. The first character of the code is the first character of character_expression and the second through fourth characters of the code are numbers that represent the letters in the expression. Vowels incharacter_expression are ignored unless they are the first letter of the string. DIFFERENCE function returns an integer value. The  integer returned is the number of characters in the SOUNDEX values that are the same. The return value ranges from 0 through 4: 0 indicates weak or no similarity, and 4 indicates strong similarity or the same values. Learning Puzzle 1: Now let us run following four queries and observe its output. SELECT SOUNDEX('SQLAuthority') SdxValue SELECT SOUNDEX('SLTR') SdxValue SELECT SOUNDEX('SaLaTaRa') SdxValue SELECT SOUNDEX('SaLaTaRaM') SdxValue When you look at the result set all the four values are same. The reason for all the values to be same is as for SQL Server SOUNDEX function all the four strings are similarly sounding string. Learning Puzzle 2: Now let us run following five queries and observe its output. SELECT DIFFERENCE (SOUNDEX('SLTR'),SOUNDEX('SQLAuthority')) SELECT DIFFERENCE (SOUNDEX('TH'),SOUNDEX('SQLAuthority')) SELECT DIFFERENCE ('SQLAuthority',SOUNDEX('SQLAuthority')) SELECT DIFFERENCE ('SLTR',SOUNDEX('SQLAuthority')) SELECT DIFFERENCE ('SLTR','SQLAuthority') When you look at the result set you will get the result in the ranges from 1 to 4. Here is how it works if your result is 0 which means absolutely not relevant to each other and if your result is 1 which means the results are relevant to each other. Have you ever used above two functions in your business need or on production server? If yes, would you please leave a comment with use cases. I believe it will be beneficial to everyone. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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