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• Should I be looking for an alternative to Zen Cart as my business grows?

  - by MarkS

  I created a business website for a family business which is growing. It's my family, and I'm a software developer, but I don't want to rebuild the wheels or be a shopping cart programmer. For this business, I need the web store to "just work", but... it gets complicated... There are two parts of this business website. One of them is driven by Wordpress and I use the awesome Thesis theme. This is modern, flexible, and saves me a lot of time from doing custom coding and styling. I couldn't be more pleased with this arrangement. The other part of the site is a Zen Cart store. It's administration and it's flexibility is frustrating and archaic Web 1.0. For the past few years, I keep hearing that the developers are working on a 2.0 version of Zen Cart, but they haven't communicated anything significant in the past few years other than to say, "When it's ready, we'll let you know." What I'm looking for in a cart, I would need to install 6-10 additional mods, and would need to do a lot of custom coding. I'm now willing to pay for a top-notch e-commerce solution for a small business that we can grow up into a larger business over time. Requirements: Extremely flexible shipping that let's us set up rules per product/category, tables of rates, calculated rates, max package weighs, etc. (flexibility like that available with CEON Advance Shipping Module for Zen Cart Coupons and gift certificates Manual order entry for phone orders Multi-channel support (We also sell on Amazon, eBay, use Google Base and we want to maintain one set of inventory and have it kept current) Decent SEO features Reviews and star-ratings on products Easy social networking features for sharing, following, liking, etc) Easy integration with AdWords and analytics tracking Modern and very usable product and store administration (Like I was saying, I'm spoiled by Wordpress and Thesis) At the end of the day, I don't care if it's a hosted solution or if I have to host it myself. I just want something that is going to stay up-to-date, regularly be maintained and improved, and if I have to update it, things like the one-click update present in Wordpress is something it has to have. Professional Webmasters, if you had to run a store / website, but you had to spend your time focusing on your sales and marketing efforts rather than diffing php files and copying and tweaking them to change even the slightest details of your site, what would you choose?

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• How one decision can turn web services to hell

  - by DigiMortal

  In this posting I will show you how one stupid decision may turn developers life to hell. There is a project where bunch of complex applications exchange data frequently and it is very hard to change something without additional expenses. Well, one analyst thought that string is silver bullet of web services. Read what happened. Bad bad mistake In the early stages of integration project there was analyst who also established architecture and technical design for web services. There was one very bad mistake this analyst made: All data must be converted to strings before exchange! Yes, that’s correct, this was the requirement. All integers, decimals and dates are coming in and going out as strings. There was also explanation for this requirement: This way we can avoid data type conversion errors! Well, this guy works somewhere else already and I hope he works in some burger restaurant – far away from computers. Consequences If you first look at this requirement it may seem like little annoying piece of crap you can easily survive. But let’s see the real consequences one stupid decision can cause: hell load of data conversions are done by receiving applications and SSIS packages, SSIS packages are not error prone and they depend heavily on strings they get from different services, there are more than one format per type that is used in different services, for larger amounts of data all these conversion tasks slow down the work of integration packages, practically all developers have been in hurry with some SSIS import tasks and some fields that are not used in different calculations in SSAS cube are imported without data conversions (by example, some prices are strings in format “1.021 $”). The most painful problem for developers is the part of data conversions because they don’t expect that there is such a stupid requirement stated and therefore they are not able to estimate the time their tasks take on these web services. Also developers must be prepared for cases when suddenly some service sends data that is not in acceptable format and they must solve the problems ASAP. This puts unexpected load on developers and they are not very happy with it because they can’t understand why they have to live with this horror if it is possible to fix. What to do if you see something like this? Well, explain the problem to customer and demand special tasks to project schedule to get this mess solved before going on with new developments. It is cheaper to solve the problems now that later.

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• Can I implement the readers and writers algorithm in OpenMP by replacing counting semaphores with another feature?

  - by DeveloperDon

  After reading about OpenMP and not finding functions to support semaphores, I did an internet search for OpenMP and the readers and writers problem, but found no suitable matches. Is there a general method for replacing counting semaphores in OpenMP with something that it supports? Or is there just a gap in the environment where it does not permit things that are asymmetrical like the third readers and writers problem shown on the following page? http://en.wikipedia.org/wiki/Readers-writers_problem#The_third_readers-writers_problem

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• What is the current state of Ubuntu's transition from init scripts to Upstart?

  - by Adam Eberlin

  What is the current state of Ubuntu's transition from init.d scripts to upstart? I was curious, so I compared the contents of /etc/init.d/ to /etc/init/ on one of our development machines, which is running Ubuntu 12.04 LTS Server. # /etc/init.d/ # /etc/init/ acpid acpid.conf apache2 --------------------------- apparmor --------------------------- apport apport.conf atd atd.conf bind9 --------------------------- bootlogd --------------------------- cgroup-lite cgroup-lite.conf --------------------------- console.conf console-setup console-setup.conf --------------------------- container-detect.conf --------------------------- control-alt-delete.conf cron cron.conf dbus dbus.conf dmesg dmesg.conf dns-clean --------------------------- friendly-recovery --------------------------- --------------------------- failsafe.conf --------------------------- flush-early-job-log.conf --------------------------- friendly-recovery.conf grub-common --------------------------- halt --------------------------- hostname hostname.conf hwclock hwclock.conf hwclock-save hwclock-save.conf irqbalance irqbalance.conf killprocs --------------------------- lxc lxc.conf lxc-net lxc-net.conf module-init-tools module-init-tools.conf --------------------------- mountall.conf --------------------------- mountall-net.conf --------------------------- mountall-reboot.conf --------------------------- mountall-shell.conf --------------------------- mounted-debugfs.conf --------------------------- mounted-dev.conf --------------------------- mounted-proc.conf --------------------------- mounted-run.conf --------------------------- mounted-tmp.conf --------------------------- mounted-var.conf networking networking.conf network-interface network-interface.conf network-interface-container network-interface-container.conf network-interface-security network-interface-security.conf newrelic-sysmond --------------------------- ondemand --------------------------- plymouth plymouth.conf plymouth-log plymouth-log.conf plymouth-splash plymouth-splash.conf plymouth-stop plymouth-stop.conf plymouth-upstart-bridge plymouth-upstart-bridge.conf postgresql --------------------------- pppd-dns --------------------------- procps procps.conf rc rc.conf rc.local --------------------------- rcS rcS.conf --------------------------- rc-sysinit.conf reboot --------------------------- resolvconf resolvconf.conf rsync --------------------------- rsyslog rsyslog.conf screen-cleanup screen-cleanup.conf sendsigs --------------------------- setvtrgb setvtrgb.conf --------------------------- shutdown.conf single --------------------------- skeleton --------------------------- ssh ssh.conf stop-bootlogd --------------------------- stop-bootlogd-single --------------------------- sudo --------------------------- --------------------------- tty1.conf --------------------------- tty2.conf --------------------------- tty3.conf --------------------------- tty4.conf --------------------------- tty5.conf --------------------------- tty6.conf udev udev.conf udev-fallback-graphics udev-fallback-graphics.conf udev-finish udev-finish.conf udevmonitor udevmonitor.conf udevtrigger udevtrigger.conf ufw ufw.conf umountfs --------------------------- umountnfs.sh --------------------------- umountroot --------------------------- --------------------------- upstart-socket-bridge.conf --------------------------- upstart-udev-bridge.conf urandom --------------------------- --------------------------- ureadahead.conf --------------------------- ureadahead-other.conf --------------------------- wait-for-state.conf whoopsie whoopsie.conf To be honest, I'm not entirely sure if I'm interpreting the division of responsibilities properly, as I didn't expect to see any overlap (of what framework handles which services). So I was quite surprised to learn that there was a significant amount of overlap in service references, in addition to being unable to discern which of the two was intended to be the primary service framework. Why does there seem to be a fair amount of redundancy in individual service handling between init.d and upstart? Is something else at play here that I'm missing? What is preventing upstart from completely taking over for init.d? Is there some functionality that certain daemons require which upstart does not yet have, which are preventing some services from converting? Or is it something else entirely?

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• Desktop Fun: Starfighters Wallpaper Collection Series 1

  - by Asian Angel

  Travelling around in large starships is great for long distance journeys or if you have a lot of cargo and supplies to move, but once you reach your destination you sometimes need something smaller to get the job done. Launch this awesome squadron of fighters on your desktop with the first in our series of Starfighters Wallpaper collections. How To Play DVDs on Windows 8 6 Start Menu Replacements for Windows 8 What Is the Purpose of the “Do Not Cover This Hole” Hole on Hard Drives?

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• What is Database Continuous Integration?

  - by David Atkinson

  Although not everyone is practicing continuous integration, many have at least heard of the concept. A recent poll on www.simple-talk.com indicates that 40% of respondents are employing the technique. It is widely accepted that the earlier issues are identified in the development process, the lower the cost to the development process. The worst case scenario, of course, is for the bug to be found by the customer following the product release. A number of Agile development best practices have evolved to combat this problem early in the development process, including pair programming, code inspections and unit testing. Continuous integration is one such Agile concept that tackles the problem at the point of committing a change to source control. This can alternatively be run on a regular schedule. This triggers a sequence of events that compiles the code and performs a variety of tests. Often the continuous integration process is regarded as a build validation test, and if issues were to be identified at this stage, the testers would simply not 'waste their time ' and touch the build at all. Such a ‘broken build’ will trigger an alert and the development team’s number one priority should be to resolve the issue. How application code is compiled and tested as part of continuous integration is well understood. However, this isn’t so clear for databases. Indeed, before I cover the mechanics of implementation, we need to decide what we mean by database continuous integration. For me, database continuous integration can be implemented as one or more of the following: 1)      Your application code is being compiled and tested. You therefore need a database to be maintained at the corresponding version. 2)      Just as a valid application should compile, so should the database. It should therefore be possible to build a new database from scratch. 3)     Likewise, it should be possible to generate an upgrade script to take your already deployed databases to the latest version. I will be covering these in further detail in future blogs. In the meantime, more information can be found in the whitepaper linked off www.red-gate.com/ci If you have any questions, feel free to contact me directly or post a comment to this blog post.

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• What is Database Continuous Integration?

  - by SQLDev

  Although not everyone is practicing continuous integration, many have at least heard of the concept. A recent poll on www.simple-talk.com indicates that 40% of respondents are employing the technique. It is widely accepted that the earlier issues are identified in the development process, the lower the cost to the development process. The worst case scenario, of course, is for the bug to be found by the customer following the product release. A number of Agile development best practices have evolved to combat this problem early in the development process, including pair programming, code inspections and unit testing. Continuous integration is one such Agile concept that tackles the problem at the point of committing a change to source control. This can alternatively be run on a regular schedule. This triggers a sequence of events that compiles the code and performs a variety of tests. Often the continuous integration process is regarded as a build validation test, and if issues were to be identified at this stage, the testers would simply not 'waste their time ' and touch the build at all. Such a ‘broken build’ will trigger an alert and the development team’s number one priority should be to resolve the issue. How application code is compiled and tested as part of continuous integration is well understood. However, this isn’t so clear for databases. Indeed, before I cover the mechanics of implementation, we need to decide what we mean by database continuous integration. For me, database continuous integration can be implemented as one or more of the following: 1)      Your application code is being compiled and tested. You therefore need a database to be maintained at the corresponding version. 2)      Just as a valid application should compile, so should the database. It should therefore be possible to build a new database from scratch. 3)     Likewise, it should be possible to generate an upgrade script to take your already deployed databases to the latest version. I will be covering these in further detail in future blogs. In the meantime, more information can be found in the whitepaper linked off www.red-gate.com/ci If you have any questions, feel free to contact me directly or post a comment to this blog post.

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• Gparted can't create partition table

  - by William

  Here's what the problem is. About a day or so ago I used Gparted live cd to create 3 NTFS primary partitions on my external 500 gig Goflex and one extended with 2 logical partitiones. I had planned to install windows 8 on the first partition, then ubuntu and kubuntu on the other 2. After I finished partitioning my drive with gparted, I booted into windows vista to make my bootable windows 8 usb to install it with, I also decided to check to make sure all my partitions were working properly. Then I found they were, and they weren't. My 50 gig first partition I had planned to install windows on showed up normal and the 300 gigs of space left in the extended partition did as well, the rest showed up as raw. So I figured alright, something went awal while making the partitions, so I booted up gparted once again. Then to my surprise gparted showed the entire drive as unallocated, and when I refreshed the list, it showed as all the partitions I had made earlier, buy with a exclamation mark by them all. So I figured ok, might be a problem with the partition table as I'd seen a similar problem in past on a drive that was not partitioned at all, so I decided to create a new partition table and take the time out again to sit and wait. Then I got a message saying gparted could not create the partition table, followed by it showing the entire drive as formatted into ntfs. After that I figured ok I'll take a break, come back in a hour, maybe it's something I did. So a hour later I came back after having booted up windows, plugged the drive in to see if by some miracle windows could access the drive. In disk management when I plugged the drive in, it would freeze attempting to read the drive, as I'd seen in the past with raw disks, yet when I unplugged it I got a glimpse of disk management showing it as a perfectly fine ntfs file system on the drive followed by a "you must format disk K in order to use it". So I then was assured the disk was raw as that is what had happened in the past, followed by a new partition table through gparted to fix the problem and a 10 hour format in windows. So I once again booted up gparted, to get the message "error fsyncing/closing/dev/sdg:input/output error" followed by "error opening dev/sdg No such file in directory" after I refreshed and somehow saw the disk show up as perfectly fine ntfs and then tried to create a new partition table to try to wipe out all my problems and start over again. And not gparted only shows the drive there about 1/10 refreshes the rest I get the directory error. If anybody can assist me in any way shape or form I will be thankful.

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• What Problems Are Better Solved By SOAP Over REST?

  In the battle for web service supremacy SOAP and REST have been battling for years. In my personal opinion this debate should have never existed. Yes, both forms can be used to create an interactive web service, but each form of a service was developed independent of each other to solve two different yet similar problems. Based my research and experience I would have to say that REST should be the preferred web service methodology and SOAP should only be used in specific situations. Note, I did not say that I was against SOAP, and in fact I actually like to use SOAP when it is needed. Criteria for using SOAP: Does the service need a guaranteed level of reliability and security? Did the provider and consumer of the service agreed on a standardized data exchange format? Does the service need data context and state management? If you answer yes to any of these questions, then you may want to consider SOAP as the format for the web service. Another way to look at the relationship between REST and SOAP is to look at the medical field.  For most things a general doctor or you family health care provider can acceptably treat most conditions from the case of a common cold to a broken bone. A general doctor more aligns with REST in my opinion because for most service requirements REST fulfills a projects needs, but what happens if you need more of an advanced examination, you would go to a specialist. A specialist would already have experience dealing with specific issues that you are experiencing giving them specific context to how best treat you going forward. SOAP acts more like a specialist doctor giving that they understand the context of an issue and can treat it based on the state of other patients they have already treated. An example of where I would use SOAP over REST in real life would be a single sign-on application. I n these cases I need to check validate a username and password for authentication and authorization of a web page request. This service would need to maintain state while it authenticated a user and while it validated access to a web page on a subsequent request. This service must process every request for access and not allow caching to ensure that every request is processed and the appropriate users are allowed to view selected web pages. References: Rozlog, M. (2010). REST and SOAP: When Should I Use Each (or Both)? Retrieved 11 20, 2011, from Infoq.com: http://www.infoq.com/articles/rest-soap-when-to-use-each

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• More info: a "stand-alone" installer for Management Studio Express 2008

  - by AaronBertrand

  Last February, I blogged about something I was initially very happy about: a stand-alone installer for Management Studio Express (SSMSE) 2008 . Now users could allegedly download a much smaller installer, and only install the client tools without having to install an instance of SQL Server Express. While the latter is true, the former remains a pipe dream. Bill Ramos stated in his 2009-02-20 announcement : "We teased out the Tools portion of SQL Server 2008 Express with Tools into it’s own download."...(read more)

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• Coding different states in Adventure Games

  - by Cardin

  I'm planning out an adventure game, and can't figure out what's the right way to implement the behaviour of a level depending on state of story progression. My single-player game features a huge world where the player has to interact with people in a town at various points in the game. However, depending on story progression, different things would be presented to the player, for e.g. the Guild Leader will change locations from the town square to various locations around the city; Doors would only unlock at certain times of the day after finishing a particular routine; Different cut-screen/trigger events happen only after a particular milestone has been reached. I naively thought of using a switch{} statement initially to decide what the NPC should say or which he could be found at, and making quest objectives interact-able only after checking a global game_state variable's condition. But I realised I would quickly run into a lot of different game states and switch-cases in order to change the behaviour of an object. That switch statement would also be massively hard to debug, and I guess it might also be hard to use in a level editor. So I thought, instead of having a single object with multiple states, maybe I should have multiple instances of the same object, with a single state. That way, if I use something like a level editor, I can put an instance of the NPC at all the different locations he could ever appear at, and also an instance for each conversation state he has. But that means there'll be a lot of inactive, invisible game objects floating around the level, which might be trouble for memory, or simply hard to see in a level editor, i don't know. Or simply, make an identical, but separate level for each game state. This feels the cleanest and bug-free way to do things, but it feels like massive manual work making sure each version of the level is really identical to each other. All my methods feel so inefficient, so to recap my question, is there a better or standardised way to implement behaviour of a level depending on state of story progression? PS: I don't have a level editor yet - thinking of using something like JME SDK or making my own.

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• Can an issue tracking system be distributed?

  - by Klaim

  I was thinking about issue tracking software like Redmine, Trac or even the one that is in Fossil and something hit me: Is there a reason why Redmine and Trac are not possible to be distributed? Or maybe it's possible and I just don't know how it's possible? If it's not possible, why? By distributed I mean like Facebook or Google or other applications that effectively runs on multiple hardware a the same time but share data.

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• Textures do not render on ATI graphics cards?

  - by Mathias Lykkegaard Lorenzen

  I'm rendering textured quads to an orthographic view in XNA through hardware instancing. On Nvidia graphics cards, this all works, tested on 3 machines. On ATI cards, it doesn't work at all, tested on 2 machines. How come? Culling perhaps? My orthographic view is set up like this: Matrix projection = Matrix.CreateOrthographicOffCenter(0, graphicsDevice.Viewport.Width, -graphicsDevice.Viewport.Height, 0, 0, 1); And my elements are rendered with the Z-coordinate 0. Edit: I just figured out something weird. If I do not call this spritebatch code above doing my textured quad rendering code, then it won't work on Nvidia cards either. Could that be due to culling information or something like that? Batch.Instance.SpriteBatch.Begin(SpriteSortMode.Immediate, BlendState.AlphaBlend, SamplerState.LinearClamp, DepthStencilState.Default, RasterizerState.CullNone); ... spriteBatch.End(); Edit 2: Here's the full code for my instancing call. public void DrawTextures() { Batch.Instance.SpriteBatch.Begin(SpriteSortMode.Texture, BlendState.AlphaBlend, SamplerState.LinearClamp, DepthStencilState.Default, RasterizerState.CullNone, textureEffect); while (texturesToDraw.Count > 0) { TextureJob texture = texturesToDraw.Dequeue(); spriteBatch.Draw(texture.Texture, texture.DestinationRectangle, texture.TintingColor); } spriteBatch.End(); #if !NOTEXTUREINSTANCING // no work to do if (positionInBufferTextured > 0) { device.BlendState = BlendState.Opaque; textureEffect.CurrentTechnique = textureEffect.Techniques["Technique1"]; textureEffect.Parameters["Texture"].SetValue(darkTexture); textureEffect.CurrentTechnique.Passes[0].Apply(); if ((textureInstanceBuffer == null) || (positionInBufferTextured > textureInstanceBuffer.VertexCount)) { if (textureInstanceBuffer != null) textureInstanceBuffer.Dispose(); textureInstanceBuffer = new DynamicVertexBuffer(device, texturedInstanceVertexDeclaration, positionInBufferTextured, BufferUsage.WriteOnly); } if (positionInBufferTextured > 0) { textureInstanceBuffer.SetData(texturedInstances, 0, positionInBufferTextured, SetDataOptions.Discard); } device.Indices = textureIndexBuffer; device.SetVertexBuffers(textureGeometryBuffer, new VertexBufferBinding(textureInstanceBuffer, 0, 1)); device.DrawInstancedPrimitives(PrimitiveType.TriangleStrip, 0, 0, textureGeometryBuffer.VertexCount, 0, 2, positionInBufferTextured); // now that we've drawn, it's ok to reset positionInBuffer back to zero, // and write over any vertices that may have been set previously. positionInBufferTextured = 0; } #endif }

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• Multiple site URLs now showing up in SERPs

  - by Scott Helme

  Recently when you search for me on Google several URLs from my blog have started showing up, instead of just the main URL. 1) https://scotthelme.co.uk/ 2) https://scotthelme.co.uk/category/wifi-pineapple-2/? 3) https://scotthelme.co.uk/wifi-pineapple-karma-sslstrip/ Is there a reason this starts happening? I have contemplated doing something to remove them but is it better to occupy the top 3 spots instead of just the top spot? Should I just leave them there?

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• Should I be put off a junior role that uses an online development test?

  - by Ninefingers

  I've applied for a junior development role, or rather been found by a recruiter looking for a developer. In order to get to a telephone interview stage I've been asked to sit one of those online coding assessments. This wasn't quite what I expected. I consider myself a fairly good developer for my age and experience, but I've no illusions about being Don Knuth or anything. The test was a series of incredibly obtuse questions asking about the results of various obscure evaluations. About 30 minutes in I was thinking to myself I hadn't intended to enter an obfuscated code contest/code golf exercise. After my last telephone interview I was asked to build something. I did. That seemed fair. Go away and work this out is more my in office experience of programming than "please evaluate this combination of lambdas, filters, maps, lists, tuples etc". So I'm a little put off, to be honest. I never claimed to know the language inside out or all the little corner cases. My questions, then: Should I be put off? Why? Why not? Are these kinds of tests what I should be expecting for junior roles? Should I learn stuff exam style? That seems to be the objective of these tests, for which you are timed and not supposed to use references or books? Normally, in the course of development I have a fairly good idea of basic types, rules, flow control and whatever. Occasionally I'll come up on something I need to use a regex for and have to go and remind myself of the exact piece of syntax I need if trying what I think should work doesn't. Or I'll come up against a module I've not used before and go and look it up. For example, if I wanted to write a server using sockets in C right now, I'd probably check the last piece of code I wrote doing that (and or the various books I have) and work from there. Chances are I probably couldn't do it exactly from scratch and from memory, although I can tell you you'd need a socket(), bind(), listen() and accept() call and you might also want select() depending on whether you intend to pthread_create or not. So I know what the calls are, but not their specific parameter list. What are your experiences if you are a recruiting manager? Are you after programmers who can quote you the API or do you not mind if your programmers have a few books on their desk and google function calls every so often?

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• Last day of early bird for PowerPivot Workshop in Dublin #ppws

  - by Marco Russo (SQLBI)

  The early bird discount for the PowerPivot Workshop in Dublin will expire today, Friday 11 March. There is also an upcoming workshop in Copenhagen (March 21-22, 2011) and a PowerPivot workshop in Zurich on April 4-5, 2011. I and Alberto are preparing new material in these days: something will integrate the workshop, other will be useful useful for future blog posts. We are discovering many new areas where the Vertipaq engine is really interesting for doing jobs he was probably not tought for! More...(read more)

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• Using SQL Sentry Plan Explorer

  - by fatherjack

  LiveJournal Tags: How To,SSMS,Tips and tricks,Execution Plans This is a quick tip that I hope will help you use SQL Sentry's Plan Explorer tool. It's a really great tool for viewing Execution Plans - something that SSMS isn't too great at. If you don't have the tool then you can download it for free from http://www.sqlsentry.net/plan-explorer/sql-server-query-view.asp. So, just a little setup is required before I can show you the tip in full. Create a directory on your Desktop called Execution...(read more)

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• A talk about observer pattern

  - by Martin

  As part of a university course I'm taking, I have to hold a 10 minute talk about the observer pattern. So far these are my points: What is it? (defenition) Polling is an alternative Polling VS Observer When Observer is better When Polling is better (taken from here) A statement that Mediator pattern is worth checking out. (I won't have time to cover it in 10 minutes) I would be happy to hear about: Any suggestions to add something? Another alternative (if exists)

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• Why lock statements don't scale

  - by Alex.Davies

  We are going to have to stop using lock statements one day. Just like we had to stop using goto statements. The problem is similar, they're pretty easy to follow in small programs, but code with locks isn't composable. That means that small pieces of program that work in isolation can't necessarily be put together and work together. Of course actors scale fine :) Why lock statements don't scale as software gets bigger Deadlocks. You have a program with lots of threads picking up lots of locks. You already know that if two of your threads both try to pick up a lock that the other already has, they will deadlock. Your program will come to a grinding halt, and there will be fire and brimstone. "Easy!" you say, "Just make sure all the threads pick up the locks in the same order." Yes, that works. But you've broken composability. Now, to add a new lock to your code, you have to consider all the other locks already in your code and check that they are taken in the right order. Algorithm buffs will have noticed this approach means it takes quadratic time to write a program. That's bad. Why lock statements don't scale as hardware gets bigger Memory bus contention There's another headache, one that most programmers don't usually need to think about, but is going to bite us in a big way in a few years. Locking needs exclusive use of the entire system's memory bus while taking out the lock. That's not too bad for a single or dual-core system, but already for quad-core systems it's a pretty large overhead. Have a look at this blog about the .NET 4 ThreadPool for some numbers and a weird analogy (see the author's comment). Not too bad yet, but I'm scared my 1000 core machine of the future is going to go slower than my machine today! I don't know the answer to this problem yet. Maybe some kind of per-core work queue system with hierarchical work stealing. Definitely hardware support. But what I do know is that using locks specifically prevents any solution to this. We should be abstracting our code away from the details of locks as soon as possible, so we can swap in whatever solution arrives when it does. NAct uses locks at the moment. But my advice is that you code using actors (which do scale well as software gets bigger). And when there's a better way of implementing actors that'll scale well as hardware gets bigger, only NAct needs to work out how to use it, and your program will go fast on it's own.

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• Is it possible to connect Flash applications to a server build with Delphi?

  - by Japie Bosman

  I have developed a client/server application using Firebird and developed with Delphi, having some clients that is also in Delphi, which I know how to do. But what I want to know is if it is possible to connect some Flash applications as clients to the Delphi developed server? The Flash applications must be able to access data in the database and also be able to update and insert records. Can something like this be done? Im using Delphi XE2 and the Flash is written with Actionscript 3

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• Surface of Revolution with 3D surface

  - by user5584

  I have to use this function to get a Surface of Revolution (homework). newVertex = (oldVertex.y, someFunc1(oldVertex.x, oldVertex.y), someFunc2(oldVertex.x, oldVertex.y)); As far as I know (FIXME) Surface of Revolution means rotations of a (2D)curve around an axis in 3D. But this vertex computing gives a 3D plane (FIXME again :D), so rotation of this isn't obvious. Am I misunderstanding something?

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• API's

  - by raghu.yadav

  lets dump API's here .... // if you want to put/get something in/from the pageFlowScope, use thisMap pfsMap = AdfFacesContext.getCurrentInstance().getPageFlowScope(); pfsMap.put(key, value); // pfsMap.put("#{pageFlowScope.param}, "sample"); pfsMap.get(key); // pfsMap.get("#{pageFlowScope.param} // if you want to set bean's property value, use this MyBackingBean bean = (MyBackingBean)pfsMap.get("my_backing_bean_name"); // the name under which the bean is registered in the task flow bean.setMyParam(newValue);

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• AWS .NET SDK v2: the message-pump pattern

  - by Elton Stoneman

  Originally posted on: http://geekswithblogs.net/EltonStoneman/archive/2013/10/11/aws-.net-sdk-v2--the-message-pump-pattern.aspxVersion 2 of the AWS SDK for .NET has had a few pre-release iterations on NuGet and is stable, if a bit lacking in step-by-step guides. There’s at least one big reason to try it out: the SQS queue client now supports asynchronous reads, so you don’t need a clumsy polling mechanism to retrieve messages. The new approach  is easy to use, and lets you work with AWS queues in a similar way to the message-pump pattern used in the latest Azure SDK for Service Bus queues and topics. I’ve posted a simple wrapper class for subscribing to an SQS hub on gist here: A wrapper for the SQS client in the AWS SDK for.NET v2, which uses the message-pump pattern. Here’s the core functionality in the subscribe method: private async void Subscribe() { if (_isListening) { var request = new ReceiveMessageRequest { MaxNumberOfMessages = 10 }; request.QueueUrl = QueueUrl; var result = await _sqsClient.ReceiveMessageAsync(request, _cancellationTokenSource.Token); if (result.Messages.Count > 0) { foreach (var message in result.Messages) { if (_receiveAction != null && message != null) { _receiveAction(message.Body); DeleteMessage(message.ReceiptHandle); } } } } if (_isListening) { Subscribe(); } } which you call with something like this: client.Subscribe(x=>Log.Debug(x.Body)); The async SDK call returns when there is something in the queue, and will run your receive action for every message it gets in the batch (defaults to the maximum size of 10 messages per call). The listener will sit there awaiting messages until you stop it with: client.Unsubscribe(); Internally it has a cancellation token which it sets when you call unsubscribe, which cancels any in-flight call to SQS and stops the pump. The wrapper will also create the queue if it doesn’t exist at runtime. The Ensure() method gets called in the constructor so when you first use the client for a queue (sending or subscribing), it will set itself up: if (!Exists()) { var request = new CreateQueueRequest(); request.QueueName = QueueName; var response = _sqsClient.CreateQueue(request); QueueUrl = response.QueueUrl; } The Exists() check has to do make a call to ListQueues on the SNS client, as it doesn’t provide its own method to check if a queue exists. That call also populates the Amazon Resource Name, the unique identifier for this queue, which will be useful later. To use the wrapper, just instantiate and go: var queueClient = new QueueClient(“ProcessWorkflow”); queueClient.Subscribe(x=>Log.Debug(x.Body)); var message = {}; //etc. queueClient.Send(message);

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• Review: Ultra-minimal Linux Desktops: Ratpoison, Awesome, fvwm

  What are you to do when you don't want a giant glitzy desktop environment for your Linux system like KDE or GNOME, but just want something lightweight with essential functionality? Try on some of the many excellent lightweight Linux window managers. In this final segment of her excellent Lightweight Linux series, Juliet Kemp reviews Awesome, fvwm, and Ratpoison.

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• What is a resonable workflow for designing webapps?

  - by Evan Plaice

  It has been a while since I have done any substantial web development and I'd like to take advantage of the latest practices but I'm struggling to visualize the workflow to incorporate everything. Here's what I'm looking to use: CakePHP framework jsmin (JavaScript Minify) SASS (Synctactically Awesome StyleSheets) Git CakePHP: Pretty self explanatory, make modifications and update the source. jsmin: When you modify a script, do you manually run jsmin to output the new minified code, or would it be better to run a pre-commit hook that automatically generates jsmin outputs of javascript files that have changed. Assume that I have no knowledge of implementing commit hooks. SASS: I really like what SASS has to offer but I'm also aware that SASS code isn't supported by browsers by default so, at some point, the SASS code needs to be transformed to normal CSS. At what point in the workflow is this done. Git I'm terrified to admit it but, the last time I did any substantial web development, I didn't use SCM source control (IE, I did use source control but it consisted of a very detailed change log with backups). I have since had plenty of experience using Git (as well as mercurial and SVN) for desktop development but I'm wondering how to best implement it for web development). Is it common practice to implement a remote repository on the web host so I can push the changes directly to the production server, or is there some cross platform (windows/linux) tool that makes it easy to upload only changed files to the production server. Are there web hosting companies that make it eas to implement a remote repository, do I need SSH access, etc... I know how to accomplish this on my own testing server with a remote repository with a separate remote tracking branch already but I've never done it on a remote production web hosting server before so I'm not aware of the options yet. Extra: I was considering implementing a javascript framework where separate javascript files used on a page are compiled into a single file for each page on the production server to limit the number of file downloads needed per page. Does something like this already exist? Is there already an open source project out in the wild that implements something similar that I could use and contribute to? Considering how paranoid web devs are about performance (and the fact that the number of file requests on a website is a big hit to performance) I'm guessing that there is some wizard hacker on the net who has already addressed this issue.

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