Search Results

Search found 58396 results on 2336 pages for 'system admin and developer'.

Page 399/2336 | < Previous Page | 395 396 397 398 399 400 401 402 403 404 405 406  | Next Page >

• need some concrete examples on user stories, tasks and how they relate to functional and technical specifications

  - by gideon

  Little heads up, Im the only lonely dev building/planning/mocking my project as I go. Ive come up with a preview release that does only the core aspects of the system, with good business value and I've coded most of the UI as dirty throw-able mockups over nicely abstracted and very minimal base code. In the end I know quite well what my clients want on the whole. I can't take agile-ish cowboying anymore because Im completely dis-organized and have no paper plan and since my clients are happy, things are getting more complex with more features and ideas. So I started using and learning Agile & Scrum Here are my problems: I know what a functional spec is.(sample): Do all user stories and/or scenarios become part of the functional spec? I know what user stories and tasks are. Are these kinda user stories? I dont see any Business Value reason added to them. I made a mind map using freemind, I had problems like this: Actor : Finance Manager Can Add a Financial Plan into the system because well thats the point of it? What Business Value reason do I add for things like this? Example : A user needs to be able to add a blog article (in the blogger app) because..?? Its the point of a blogger app, it centers around that feature? How do I go into the finer details and system definitions: Actor: Finance Manager Action: Adds a finance plan. This adding is a complicated process with lots of steps. What User Story will describe what a finance plan in the system is ?? I can add it into the functional spec under definitions explaining what a finance plan is and how one needs to add it into the system, but how do I get to the backlog planning from there? Example: A Blog Article is mostly a textual document that can be written in rich text in the system. To add a blog article one must...... But how do you create backlog list/features out of this? Where are the user stories for what a blog article is and how one adds/removes it? Finally, I'm a little confused about the relations between functional specs and user stories. Will my spec contain user stories in them with UI mockups? Now will these user stories then branch out tasks which will make up something like a technical specification? Example : EditorUser Can add a blog article. Use XML to store blog article. Add a form to add blog. Add Windows Live Writer Support. That would be agile tasks but would that also be part of/or form the technical specs? Some concrete examples/answers of my questions would be nice!!

  Read the article

• Updating a Progress Bar within the Status Bar [migrated]

  - by Muhnamana

  I'm trying to figure out how to incorporate a progress bar within the status bar to show how much processing is completed. Below is my example of updating the progress bar (not sure if this is the correct way or not) Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick ToolStripProgressBar1.Value = ToolStripProgressBar1.Value + 2 If ToolStripProgressBar1.Value = 100 Then ToolStripProgressBar1.Value = 0 ToolStripProgressBar1.Value = ToolStripProgressBar1.Value + 2 Timer1.Enabled = True End If End Sub Here is the code within the button. Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1Run.Click ToolStripStatusLabel1.Text = "Processing..." Timer1.Enabled = True 'more code to be inserted here End Sub What I'm not sure is how to update the progress bar based on the amount of code you have and once the processing is complete, update the ToolStripStatusLabel1 to show "Processing...Complete!".

  Read the article

• Entity Framework and distributed Systems

  - by Dirk Beckmann

  I need some help or maybe only a hint for the right direction. I've got a system that is sperated into two applications. An existing VB.NET desktop client using Entity Framework 5 with code first approach and a asp.net Web Api client in C# that will be refactored right yet. It should be possible to deliver OData. The system and the datamodel is still involving and so migrations will happen in undefined intervalls. So I'm now struggling how to manage my database access on the web api system. So my favourd approch would be us Entity Framework on both systems but I'm running into trouble while creating new migrations. Two solutions I've thought about: Shared Data Access dll The first idea was to separate the data access layer to a seperate project an reference from each of the systems. The context would be the same as long as the dll is up to date in each system. This way both soulutions would be able to make a migration. The main problem ist that it is much more complicate to update a web api system than it is with the client Click Once Update Solution and not every migration is important for the web api. This would couse more update trouble and out of sync libraries Database First on Web Api The second idea was just to use the database first approch an on web api side. But it seems that all annotations will be lost by each model update. Other solutions with stored procedures have been discarded because of missing OData support and maintainability. Does anyone run into same conflicts or has any advices how such a problem can be solved!

  Read the article

• Frequent GUI pauses in Ubuntu 13.04 / Unity / Intel HD4000

  - by Simon

  I'm experiencing very frequent (and regular) GUI pauses on my system. Every 30 seconds (pretty much exactly) the GUI will freeze for maybe .25 to .5 seconds. The mouse stops moving, keys stop echoing and a stopwatch timer briefly pauses. I'm using the Intel Graphics driver available from: https://download.01.org/gfx/ubuntu/13.04/main I've looked in a few places and tried a few things for a solution: I've checked cron and anacron for scheduled processes. I've disabled background processes (eg mysql, postgres, apache) not that these were doing anything anyway I've checked the following posts and tried the suggestions there: Unity GUI pauses/freezes for less than a few seconds How to go about troubleshooting frequent system pauses I've watched the system using top and System Monitor and there are no spikes (or even blips) of cpu usage when the pauses occur. There are no obvious error messages in dmesg or syslog There is loads of free RAM (8GB+) and no swap usage If it helps it's a ZooStorm i5 laptop with a HD4000 GPU, 16GB Ram and an SSD. Any help / suggestions would be very gratefully received.

  Read the article

• Project Management Tool for developers and sysadmins: shared or separate?

  - by David

  Should a team of system administrators who are on a software development project share a project management tool with the developers or use their own separate one? We use Trac and I see the benefit in sharing since inter-team tasks can be maintained by a single system where there may be cross-over or misfiled bugs (e.g. an apparent bug which turns out to be a server configuration issue or a development cycle which needs a server to be configured before it can start) However sharing could be difficult since many system administration tasks don't coincide with a single development milestone if at all. So should a system administration team use a separate PM Tool or share the same one with the developers? If they should share, then how?

  Read the article

• Oracle Magazine, May/June 2006

  Oracle Magazine May/June 2006 features articles on Oracle developer tools, Semantic Web, Lucasfilm, Manpower, PL/SQL Best Practices, SQL Developer, ODP.NET and Oracle Database 10g Release 2, PHP, Oracle Application Express, and much more.

  Read the article

• Bug Tracking Etiquette - Necromancy or Duplicate?

  - by Shauna

  I came across a really old (2+ years) feature request issue in a bug tracker for an open source project that was marked as "resolved (won't fix)" due to the lack of tools required to make the requested enhancement. In the time elapsed since that determination was made, new tools have been developed that would allow it to be resolved, and I'd like to bring that to the attention of the community for that application. However, I'm not sure as to what the generally accepted etiquette is for bug tracking in cases like this. Obviously, if the system explicitly states to not duplicate and will actively mark new items as duplicates (much in the way the SE sites do), then the answer would be to follow what the system says. But what about when the system doesn't explicitly say that, or a new user can't easily find a place that says with the system's preference is? Is it generally considered better to err on the side of duplication or necromancy? Does this differ depending on whether it's a bug or a feature request?

  Read the article

• Pulling changes from master to my work branch?

  - by Utkarsh Sinha

  There's two of us working on something. We're using this branch structure master dev-A dev-B We both work on separate branches (dev-A,B) and whenever we're done - we promote our changes to master. But the drawback of this is we can't get changes the other developer makes. Everything exists in the master tree - but we can't get the latest updates the other developer made. Is there a way to resolve this or should we change our branch structure (per feature?)?

  Read the article

• Take care to unhook Anonymous Delegates

  - by David Vallens

  Anonymous delegates are great, they elimiante the need for lots of small classes that just pass values around, however care needs to be taken when using them, as they are not automatically unhooked when the function you created them in returns. In fact after it returns there is no way to unhook them. Consider the following code.   using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Diagnostics; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { SimpleEventSource t = new SimpleEventSource(); t.FireEvent(); FunctionWithAnonymousDelegate(t); t.FireEvent(); } private static void FunctionWithAnonymousDelegate(SimpleEventSource t) { t.MyEvent += delegate(object sender, EventArgs args) { Debug.WriteLine("Anonymous delegate called"); }; t.FireEvent(); } } public class SimpleEventSource { public event EventHandler MyEvent; public void FireEvent() { if (MyEvent == null) { Debug.WriteLine("Attempting to fire event - but no ones listening"); } else { Debug.WriteLine("Firing event"); MyEvent(this, EventArgs.Empty); } } } } If you expected the anonymous delegates do die with the function that created it then you would expect the output Attempting to fire event - but no ones listeningFiring eventAnonymous delegate calledAttempting to fire event - but no ones listening However what you actually get is Attempting to fire event - but no ones listeningFiring eventAnonymous delegate calledFiring eventAnonymous delegate called In my example the issue is just slowing things down, but if your delegate modifies objects, then you could end up with dificult to diagnose bugs. A solution to this problem is to unhook the delegate within the function var myDelegate = delegate(){Console.WriteLine("I did it!");}; MyEvent += myDelegate; // .... later MyEvent -= myDelegate;

  Read the article

• Fresh Diagnose

  A free utility for analyzing and benchmarking your computer system

  Read the article

• RDP over VPN only

  - by shiva

  I know this question has been asked many a times here. But i want to gain certain perspective here. I have enabled VPN on certain systems and then can access remote system using rdp. However they can access the remote system without rdp as well. Is this because all these systems are in same lan group? How can i ensure that rdp works only when connected to vpn? I am looking at one vpn system and people should log into that system and then connect to vpn and then access remote system using rdp. I know that this can be achieved but i am not sure how to go about it. please guide me

  Read the article

• Penny auction concept and how the timer works

  - by madi

  I am creating a penny auction site using PHP yii framework. The main consideration of the system is to update the database records of all active auctions (max 15 auctions) with the current ticker timer. I am seeking for advice on how i should design the system where every auction item will have a its own countdown timer stored in the database and when someone bids the auction item, the counter resets to 2 min. Every users who are connected to the system should see the same countdown timer for that particular auction. I am little confused on how i should design the system. Will there be a performance issue when there are frequent updates to the database (Mysql) where 15 active auctions are updated every seconds, the countdown timer decreases by a second in the database table for the particular auction. Schema Sample for auction_lots: Auction_id,startdatetime,counter_timer,status I am seeking for advice on how I should design this. Please help. Thank you!

  Read the article

• Java keyboard input [on hold]

  - by dØd

  I'm trying to implement a input system that can detect whether a certain key was held or was only pressed briefly. So far I have this: KEY_INTERACTION_TRESHOLD = 400ms //inside a constructor shouldMeasure = true; @Override public void keyPressed(KeyEvent e) { if (shouldMeasure) { startTime = System.currentTimeMillis(); shouldMeasure = false; return; } System.out.println("Button is held down"); e.consume(); } @Override public void keyReleased(KeyEvent e) { if (System.currentTimeMillis() - startTime < KEY_INTERACTION_TRESHOLD) { System.out.println("Button was only pressed briefly"); } startTime = 0; shouldMeasure = true; e.consume(); } Now this works, but the problem is that there is this delay between when I press a key to hold and when the message 'Button is held down' gets displayed. I understand why this delay occurs (for example when you press and hold a letter there will be a similar delay between the first and the second letter printed out), but I would like to somehow avoid it. I'm using only the Java API.

  Read the article

• Paranoid management, contractor checking work [closed]

  - by user833345

  Just wanted to get some opinions and experiences on an issue I'm having at work. First, a little background. I've been working at a company for some time (past any probation periods) and rewriting a horrendous system. No tests, incomplete and broken functionality everywhere, enough copypasta to feed a small village, redundant code, more unused SQL tables than used ones and terrible performance. I've never seen such bad code, pretty much all of it is worthy of being posted on TheDailyWTF. The company has been operating for a number of years and have had a string of bad developers working on this system. I made a call on rewriting instead of refactoring since I judged it to be less work overall and decided that the result will address the requirements more appropriately, since the central requirement is to have a future-proof system for the next decade with plenty of room to scale up. Refactoring would have entailed untangling a huge ball of yarn and at the same time integrating it with a proper foundation or building a foundation from scratch. I've introduced the latest spiffy framework, unit & functional testing, CI, a bug tracker and agile workflow to the environment. I've fixed most of the performance issues of the old system (there were no indexes on any of the tables, for example). I've created an automated deployment process for the old system. The CTO has been maintaining the old system while I have been building the new one and he has been advising management that everything is being done as per best practices. However, management is hiring a contractor to come in and verify my work. In my experience, this is unprecedented. I can understand their reasoning to an extent, since they've had bad luck in the past, but can't help but feel somewhat offended at the fact that they distrust two senior developers who have been working with them for some time enough that a third party is being brought in. And it's not just me who is under watch - people's emails are constantly checked, someone had a remote desktop application installed on their computer of which I was asked to check the usage logs to try to determine if they were stealing sensitive data and there are CCTV cameras in one of the rooms. It's the first time I've decided to disable my Skype history at work. Am I right to feel indignant here? Has anyone else ever encountered such a situation? If so, how did it work out in the end? Was it worth sticking around? Should I just find another job?

  Read the article

• Upgrade from 10.10 to 11.04

  - by hemanta pathak

  On doing an upgrade from 10.10. to 11.04 using Upgrade Manager everything works fine. But on installing a software that bundle its owns runtime environment( loader and system files) and installs the custom runtime ( basically loader) in the location where the native one resides, the above mentioned upgrade fails.(Upgrade starts and after sometime it encounters an error and aborts.) Basically , /usr/bin/dpkg throws up an error on being unable to locate a system shared library in the aforesaid third party runtime folder ( /usr/bin/dpkg should not search the third party runtime folder.Instead it should look at the system default folder) But if we remove the installed third party loader from the default system location /lib and place it in some other location , the upgrade problem goes away. This makes me believe /usr/bin/dpkg invokes(loads) the wrong loader and as such goes looking for the dependent libraries in the third party folder. Can someone take a look at this ? is there some bug with dpkg

  Read the article

• Oracle E-Business Suite Tip : SQL Tracing

  - by Giri Mandalika

  Issue: Attempts to enable SQL tracing from concurrent request form fails with error: Function not available to this responsibility. Change Responsibilities or contact your System Administrator Resolution: Switch responsibility to "System Administrator". Navigate to System - Profiles, and query for "%Diagnostics% ("Utilities : Diagnostics")". Once found the profile, change its value to "Yes". Restart web browser and try enabling SQL trace again.

  Read the article

• Is it okay to have people with multiple roles in a Scrum team?

  - by Wayne M

  I'm evaluating some Agile-style methodologies for possible introduction to my team. With Scrum, is it allowable to have the same person perform multiple roles? We have a small team of four developers and a web designer; we don't really have a lead (I fulfill this role), QA testers or business analysts, and all of our development tasks come from the CIO. Automated testing is seen as a total waste of time, and everything focuses on speed and not quality. What will happen is the CIO will come up with a development task (whether a feature or a bug) and give it to a developer (not to the whole team, to an individual, often in private or out of the blue) who is then expected to get it completed. The CIO doesn't gather requirements beyond the initial idea (and this has bitten us before as we'll implement something only to find out that none of the end users can use the feature, because they weren't consulted or even informed about it before we developed it, and in a panic we'll be told to revert the change) but requires say in/approval of everything that we do. First things first, is a Scrum style something to consider to introduce some standards and practices? From reading, Scrum seems to rely on a bit more trust and communication and focuses more on project management than on development, which is something we are completely devoid of as we don't have any semblance of project management at present. Second, if it can work is it unreasonable for someone, let's say myself, to act as both ScrumMaster and a developer? Or for a developer to also be the Product Owner (although chances are this will be the CIO, who isn't a developer)? I realize the Scrum Master and the Product Owner should be different people but at the same time I don't think we have anyone who has the qualities of a Product Owner (chances are it would turn into a "I need all these stories, I don't care how but get it done" type of deal and/or any freeze would be unfrozen on a whim). It seems to me that I might need to pick and choose pieces of Scrum/XP/Lean to compensate for how things are done currently, as it's highly unlikely that the mentality can be changed; for instance Pair Programming would never fly (seen as a waste, you get half the tasks done if you need two people for everything), TDD would be a hard sell, but short cycles would be welcomed.

  Read the article

• How do I know if my serial adapter card is working?

  - by Ingram

  I just installed a 2 port serial adapter in my Ubuntu 10.10 system, then I tried following this tutorial that I used on my old system to connect to a cisco router (my old system had an onboard serial adapter, and the tutorial worked just fine). I can't get my system to connect to the cisco router, so I'm wondering if the card even works in Ubuntu. How can I tell if the card actually works with Ubuntu? #dmesg | grep tty [ 0.000000] console [tty0] enabled [ 0.358667] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A [ 0.358994] 00:0c: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A [ 0.359128] ttyS1: detected caps 00000700 should be 00000100 [ 0.359132] 0000:03:00.0: ttyS1 at MMIO 0xfeafd000 (irq = 16) is a 16C950/954 [ 0.359191] ttyS2: detected caps 00000700 should be 00000100 [ 0.359195] 0000:03:00.0: ttyS2 at MMIO 0xfeafd200 (irq = 16) is a 16C950/954

  Read the article

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

  - by ryanabr

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

  Read the article

• Monitoring JSON requests sent/received from the browser?

  - by Uwe Keim

  Having a website that generates and receives JSON requests via AJAX, I failed to find a tool that shows me live the communication including the content of the JSON calls. I thought that the Google Chrome developer tools or the IE 9 developer tools do have such a feature, but again, I failed. Searching Google, I failed too. So my question is: Is there a client-side tool to monitor the content of JSON requests that a website sends to the server?

  Read the article

• Re-generating SQL Server Logins

  SQL Server stores all login information on security catalog system tables. By querying the system tables, SQL statements can be re-generated to recover logins, including password, default schema/database, server/database role assignments, and object level permissions. A comprehensive permission report can also be produced by combining information from the system metadata. The Future of SQL Server Monitoring "Being web-based, SQL Monitor 2.0 enables you to check on your servers from almost any location" Jonathan Allen.Try SQL Monitor now.

  Read the article

• How to change ownership for an external HDD?

  - by Angstrem

  I've got an external HDD (640 GB), with file system FAT32. I want to change the ownership of it from root (default) to angstrem (my username). The system is mounted to /media/exthdd. I try to do that by a command: sudo chown -vR angstrem:angstrem /media/exthdd and after that the system gives me an error: chown: changing ownership of `/media/exthdd': Operation not permitted If anybody knows, please tell me, how to change ownership of that HDD?

  Read the article

• shutdown logging in ubuntu 10.04 & 11.10

  - by Joe

  When my system starts up it logs everything into syslog/dmesg. And I can review it for problems. When my system shuts down, where does that get logged? I didn't see anything obvious in /var/log in 10.04. (My 11.10 system is out of reach at the moment.) I looked at How do I turn on 'shutdown logging' or operating system tracing? but didn't see anything that helped. I use kubuntu, but all of the stuff at this level is probably the same.

  Read the article

• SQL 2014 does data the way developers want

  - by Rob Farley

  A post I’ve been meaning to write for a while, good that it fits with this month’s T-SQL Tuesday, hosted by Joey D’Antoni (@jdanton) Ever since I got into databases, I’ve been a fan. I studied Pure Maths at university (as well as Computer Science), and am very comfortable with Set Theory, which undergirds relational database concepts. But I’ve also spent a long time as a developer, and appreciate that that databases don’t exactly fit within the stuff I learned in my first year of uni, particularly the “Algorithms and Data Structures” subject, in which we studied concepts like linked lists. Writing in languages like C, we used pointers to quickly move around data, without a database in sight. Of course, if we had a power failure all this data was lost, as it was only persisted in RAM. Perhaps it’s why I’m a fan of database internals, of indexes, latches, execution plans, and so on – the developer in me wants to be reassured that we’re getting to the data as efficiently as possible. Back when SQL Server 2005 was approaching, one of the big stories was around CLR. Many were saying that T-SQL stored procedures would be a thing of the past because we now had CLR, and that obviously going to be much faster than using the abstracted T-SQL. Around the same time, we were seeing technologies like Linq-to-SQL produce poor T-SQL equivalents, and developers had had a gutful. They wanted to move away from T-SQL, having lost trust in it. I was never one of those developers, because I’d looked under the covers and knew that despite being abstracted, T-SQL was still a good way of getting to data. It worked for me, appealing to both my Set Theory side and my Developer side. CLR hasn’t exactly become the default option for stored procedures, although there are plenty of situations where it can be useful for getting faster performance. SQL Server 2014 is different though, through Hekaton – its In-Memory OLTP environment. When you create a table using Hekaton (that is, a memory-optimized one), the table you create is the kind of thing you’d’ve made as a developer. It creates code in C leveraging structs and pointers and arrays, which it compiles into fast code. When you insert data into it, it creates a new instance of a struct in memory, and adds it to an array. When the insert is committed, a small write is made to the transaction to make sure it’s durable, but none of the locking and latching behaviour that typifies transactional systems is needed. Indexes are done using hashes and using bw-trees (which avoid locking through the use of pointers) and by handling each updates as a delete-and-insert. This is data the way that developers do it when they’re coding for performance – the way I was taught at university before I learned about databases. Being done in C, it compiles to very quick code, and although these tables don’t support every feature that regular SQL tables do, this is still an excellent direction that has been taken. @rob_farley

  Read the article

• Mutable Records in F#

  - by MarkPearl

  I’m loving my expert F# book – today I thought I would give a post on using mutable records as covered in Chapter 4 of Expert F#. So as they explain the simplest mutable data structures in F# are mutable records. The whole concept of things by default being immutable is a new one for me from my C# background. Anyhow… lets look at some C# code first. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace MutableRecords { public class DiscreteEventCounter { public int Total { get; set; } public int Positive { get; set; } public string Name { get; private set; } public DiscreteEventCounter(string name) { Name = name; } } class Program { private static void recordEvent(DiscreteEventCounter s, bool isPositive) { s.Total += 1; if (isPositive) s.Positive += 1; } private static void reportStatus (DiscreteEventCounter s) { Console.WriteLine("We have {0} {1} out of {2}", s.Positive, s.Name, s.Total); } static void Main(string[] args) { var longCounter = new DiscreteEventCounter("My Discrete Counter"); recordEvent(longCounter, true); recordEvent(longCounter, true); reportStatus(longCounter); Console.ReadLine(); } } } Quite simple, we have a class that has a few values. We instantiate an instance of the class and perform increments etc on the instance. Now lets look at an equivalent F# sample. namespace EncapsulationNS module Module1 = open System type DiscreteEventCounter = { mutable Total : int mutable Positive : int Name : string } let recordEvent (s: DiscreteEventCounter) isPositive = s.Total <- s.Total+1 if isPositive then s.Positive <- s.Positive+1 let reportStatus (s: DiscreteEventCounter) = printfn "We have %d %s out of %d" s.Positive s.Name s.Total let newCounter nm = { Total = 0; Positive = 0; Name = nm } // // Using it... // let longCounter = newCounter "My Discrete Counter" recordEvent longCounter (true) recordEvent longCounter (true) reportStatus longCounter System.Console.ReadLine() Notice in the type declaration of the DiscreteEventCounter we had to explicitly declare that the total and positive value holders were mutable. And that’s it – a very simple example of mutable types.

  Read the article

< Previous Page | 395 396 397 398 399 400 401 402 403 404 405 406  | Next Page >