Search Results

Search found 22065 results on 883 pages for 'performance testing'.

Page 744/883 | < Previous Page | 740 741 742 743 744 745 746 747 748 749 750 751  | Next Page >

  • Is any solution the correct solution?

    - by Eli
    I always think to myself after solving a programming challenge that I have been tied up with for some time, "It works, thats good enough". I don't think this is really the correct mindset, in my opinion and I think I should always be trying to code with the greatest performance. Anyway, with this said, I just tried a ProjectEuler question. Specifically question #2. How could I have improved this solution. I feel like its really verbose. Like I'm passing the previous number in recursion. <?php /* Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ... Find the sum of all the even-valued terms in the sequence which do not exceed four million. */ function fibonacci ( $number, $previous = 1 ) { global $answer; $fibonacci = $number + $previous; if($fibonacci > 4000000) return; if($fibonacci % 2 == 0) { $answer = is_numeric($answer) ? $answer + $fibonacci : $fibonacci; } return fibonacci($fibonacci, $number); } fibonacci(1); echo $answer; ?> Note this isn't homework. I left school hundreds of years ago. I am just feeling bored and going through the Project Euler questions

    Read the article

  • Statically Compiling Qt 4.6.2

    - by geeko
    This what I did but it results in errors: 1: In win32-msvc2008\qmake.conf I set QMAKE_CFLAGS_RELEASE = -O1 -Og -GL -MD 2: From MSVC2008 CMD I run vcvarsall.bat x86 and vcvars32.bat "C:\Program Files\Microsoft Visual Studio 9.0\VC\bin 3: From Qt 4.6.2 CMD I run the following C:\Qt\4.6.2configure -release -nomake examples -nomake demos -no-exceptions -n o-stl -no-rtti -no-qt3support -no-scripttools -no-openssl -no-opengl -no-webkit -no-phonon -no-style-motif -no-style-cde -no-style-cleanlooks -no-style-plastique -no-sql-sqlite -platform win32-msvc2008 -static -qt-libjpeg -qt-zlib -qt-libpng and then nmake However, I ended up every time with these errors: link /LIBPATH:"c:\Qt\4.6.2\lib" /LIBPATH:"c:\Qt\4.6.2\lib" /NOLOGO /INCR EMENTAL:NO /MANIFEST /MANIFESTFILE:"tmp\obj\release_static\assistant_adp.interme diate.manifest" /SUBSYSTEM:WINDOWS "/MANIFESTDEPENDENCY:type='win32' name='Micro soft.Windows.Common-Controls' version='6.0.0.0' publicKeyToken='6595b64144ccf1df ' language='' processorArchitecture=''" /OUT:......\bin\assistant_adp.exe @C :\DOCUME~1\Geeko\LOCALS~1\Temp\nm3F8.tmp fontpanel.obj : MSIL .netmodule or module compiled with /GL found; restarting li nk with /LTCG; add /LTCG to the link command line to improve linker performance main.obj : error LNK2001: unresolved external symbol "class QObject * __cdecl qt _plugin_instance_qjpeg(void)" (?qt_plugin_instance_qjpeg@@YAPAVQObject@@XZ) ......\bin\assistant_adp.exe : fatal error LNK1120: 1 unresolved externals NMAKE : fatal error U1077: '"C:\Program Files\Microsoft Visual Studio 9.0\VC\BIN \link.EXE"' : return code '0x460' Stop. NMAKE : fatal error U1077: '"C:\Program Files\Microsoft Visual Studio 9.0\VC\BIN \nmake.exe"' : return code '0x2' Stop. NMAKE : fatal error U1077: 'cd' : return code '0x2' Stop. NMAKE : fatal error U1077: 'cd' : return code '0x2' Stop. NMAKE : fatal error U1077: 'cd' : return code '0x2' Stop. Thank you in deed.

    Read the article

  • What's are the best readings to start using WPF instead of WinForms?

    - by Ivan
    Keeping in mind what CannibalSmith once said - "All the answers are saying "WPF is different". That's a huge understatement. You not only have to learn lots of new stuff - you must forget everything you've learned from Forms. It's a completely new way of doing UI." .. and having many years of experience with visual Windows desktop applications development (VB6, Borland C++ Builder VCL, WinForms) (which is hard to forget), how do I quickly move to developing to say well-formed WPF applications with Visual Studio? I don't need boozy-woozy graphics to give my app look and feel of a Hollywood blockbuster or a million dollar pyjamas. I always loved tidiness of standard Windows common controls and UI design guidelines, end even more I enjoyed them under Vista Glass Aero Graphite sauce. I am perfectly satisfied with WinForms but I want to my applications to be built of the most efficient and up-to-date standard technologies and architectured according to the most efficient and flexible patterns of today and tomorrow, leveraging interface-based integration and functionality reuse and to take all advantages of modern hardware and APIs to maximize performance, usability, reliability, maintainability, extensibility, etc. I very much like the idea of separating view, logic and data, letting a view to take all advantages of the platform (may it run as a web browser applet on a thin client or as a desktop application on a PC with a latest GPU), letting logic be reused, parallelized and seamlessly evolve, storing data in a well structured format in a right place. But... while moving from VB6 to Borland C++ Builder was very easy (no books/tutorials needed to turn it on and start working) (assuming I already knew C++), moving from BCB to WinForms was the same seamless, it does not seem any obvious to me how to do with WPF. So how do I best convert myself from a WinForms developer into a right-way thinking and doing WPF developer?

    Read the article

  • 48-bit bitwise operations in Javascript?

    - by randomhelp
    I've been given the task of porting Java's Java.util.Random() to JavaScript, and I've run across a huge performance hit/inaccuracy using bitwise operators in Javascript on sufficiently large numbers. Some cursory research states that "bitwise operators in JavaScript are inherently slow," because internally it appears that JavaScript will cast all of its double values into signed 32-bit integers to do the bitwise operations (see https://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Operators/Bitwise_Operators for more on this.) Because of this, I can't do a direct port of the Java random number generator, and I need to get the same numeric results as Java.util.Random(). Writing something like this.next = function(bits) { if (!bits) { bits = 48; } this.seed = (this.seed * 25214903917 + 11) & ((1 << 48) - 1); return this.seed >>> (48 - bits); }; (which is an almost-direct port of the Java.util.Random()) code won't work properly, since Javascript can't do bitwise operations on an integer that size.) I've figured out that I can just make a seedable random number generator in 32-bit space using the Lehmer algorithm, but the trick is that I need to get the same values as I would with Java.util.Random(). What should I do to make a faster, functional port?

    Read the article

  • Best way to manipulate and compare strings

    - by vtortola
    I'm developing a REST service, so a request could be something like this: /Data/Main/Table=Customers/ I need to get the segments one by one, and for each segment I will decide wich object I'm going to use, after I'll pass to that object the rest of the query so it can decide what to do next. Basically, the REST query is a path on a tree :P This imply lots String operations (depending on the query complexity), but StringBuilder is useful just for concatenations and remove, you cannot perform a search with IndexOf or similar. I've developed this class that fulfill my requirement, but the problem is that is manipulating Strings, so every time I get one segment ... I'll create extra Strings because String is an inmutable data type: public class RESTQueryParser { String _query; public RESTQueryParser(String query) { _query = query; } public String GetNext() { String result = String.Empty; Int32 startPosition = _query.StartsWith("/", StringComparison.InvariantCultureIgnoreCase) ? 1 : 0; Int32 i = _query.IndexOf("/", startPosition, StringComparison.InvariantCultureIgnoreCase) - 1; if (!String.IsNullOrEmpty(_query)) { if (i < 0) { result = _query.Substring(startPosition, _query.Length - 1); _query = String.Empty; } else { result = _query.Substring(startPosition, i); _query = _query.Remove(0, i + 1); } } return result; } } The server should support a lot of calls, and the queries could be huge, so this is gonna be a very repetitive task. I don't really know how big is the impact on the memory and the performance, I've just readed about it in some books. Should I implement a class that manage a Char[] instead Strings and implement the methods that I want? Or should be ok with this one? Regular expressions maybe?

    Read the article

  • IIS7 ASP.NET Session drops in seconds

    - by shxo
    For testing I have 1 isolated page - no masters, controls, …. My sessions are lost after about 30 seconds. I’ve tried setting timeout on the page itself, in web.config, both, and neither. Tried forms authentication with timeout and windows authentication. Recycle the AppPool after changes. I can response.write from the Session_Start , but I never get any response.writes from the Session_End. Some things I’ve tried: <sessionState mode="InProc" stateConnectionString="tcpip=127.0.0.1:42424" sqlConnectionString="data source=127.0.0.1;" cookieless="false" timeout="20" /> <sessionState mode="InProc" cookieless="false" timeout="20"/> <sessionState mode="InProc" timeout="20"/> <sessionState timeout="20"/> No luck. My runtime is set to: <httpRuntime useFullyQualifiedRedirectUrl="true" maxRequestLength="204800" requestLengthDiskThreshold="204800" executionTimeout="600" /> I don’t know what this would be relevant, but I can’t think of anything else to post! Thanks!

    Read the article

  • NHibernate.Search - async mode

    - by Atul
    Hi, I am using NHibernate Lucene search in my project. Lucene.Net.dll - v - 2.3.1.3 NHibernate.dll - v - 2.1.0.4000 At this point I am trying to use async option for indexing and used following options config.SetProperty(NHibernate.Search.Environment.WorkerExecution, "async"); config.SetProperty(NHibernate.Search.Environment.WorkerThreadPoolSize, "1"); config.SetProperty(NHibernate.Search.Environment.WorkerWorkQueueSize, "5000"); Questions 1) My initial index was not build with this option, when used these settings first time, I had error saying NHibernate.Search.dll not found. When I deleted existing index and then started working, it went fine. Do we need to rebuild indexes whenever we change config settings like above ? 2) How size of index should be interpreted; i.e. initially my index was about 400MB (build over the last few months), which I deleted. Later when I reindexed, the size of index went down to 5MB ! Search appear to be alright after limited testing, but such a change appeared bit scary. Should we delete/rebuild indexes once in a while & is it normal to change this drastically ? 3) Is my above setting is OK ? When I had WorkerThreadPoolSize=5, I once got Dr Watson kind of error. Please advise on best practices of using async configuration for search. Regards, Atul

    Read the article

  • Experience migrating legacy Cobol/PL1 to Java

    - by MadMurf
    ORIGINAL Q: I'm wondering if anyone has had experience of migrating a large Cobol/PL1 codebase to Java? How automated was the process and how maintainable was the output? How did the move from transactional to OO work out? Any lessons learned along the way or resources/white papers that may be of benefit would be appreciated. EDIT 7/7: Certainly the NACA approach is interesting, the ability to continue making your BAU changes to the COBOL code right up to the point of releasing the JAVA version has merit for any organization. The argument for procedural Java in the same layout as the COBOL to give the coders a sense of comfort while familiarizing with the Java language is a valid argument for a large organisation with a large code base. As @Didier points out the $3mil annual saving gives scope for generous padding on any BAU changes going forward to refactor the code on an ongoing basis. As he puts it if you care about your people you find a way to keep them happy while gradually challenging them. The problem as I see it with the suggestion from @duffymo to Best to try and really understand the problem at its roots and re-express it as an object-oriented system is that if you have any BAU changes ongoing then during the LONG project lifetime of coding your new OO system you end up coding & testing changes on the double. That is a major benefit of the NACA approach. I've had some experience of migrating Client-Server applications to a web implementation and this was one of the major issues we encountered, constantly shifting requirements due to BAU changes. It made PM & scheduling a real challenge. Thanks to @hhafez who's experience is nicely put as "similar but slightly different" and has had a reasonably satisfactory experience of an automatic code migration from Ada to Java. Thanks @Didier for contributing, I'm still studying your approach and if I have any Q's I'll drop you a line.

    Read the article

  • How do I cast <T> to varbinary and be still be able to perform a CONVERT on the sql side? Implicatio

    - by Biff MaGriff
    Hello, I'm writing this application that will allow a user to define custom quizzes and then allow another user to respond to the questions. Each question of the quiz has a corresponding datatype. All the responses to all the questions are stored vertically in my [Response] table. I currently use 2 fields to store the response. //Response schema ResponseID int QuizPersonID int QuestionID int ChoiceID int //maps to Choice table, used for drop down lists ChoiceValue varbinary(MAX) //used to store a user entered value I'm using .net 3.5 C# SQL Server 2008. I'm thinking that I would want to store different datatypes in the same field and then in my SQL report proc I would CONVERT to the proper datatype. I'm thinking this is ideal because I only have to check one field. I'm also thinking it might be more trouble than it is worth. I think my other options are to; store the data as strings in the db (yuck), or to have a column for each datatype I might use. So what I would like to know is, how would I format my datatypes in C# so that they can be converted properly in SQL? What is the performance hit for converting in SQL? Should I just make a whole wack of columns for each datatype?

    Read the article

  • Required Working Precision for the BBP Algorithm?

    - by brainfsck
    Hello, I'm looking to compute the nth digit of Pi in a low-memory environment. As I don't have decimals available to me, this integer-only BBP algorithm in Python has been a great starting point. I only need to calculate one digit of Pi at a time. How can I determine the lowest I can set D, the "number of digits of working precision"? D=4 gives me many correct digits, but a few digits will be off by one. For example, computing digit 393 with precision of 4 gives me 0xafda, from which I extract the digit 0xa. However, the correct digit is 0xb. No matter how high I set D, it seems that testing a sufficient number of digits finds an one where the formula returns an incorrect value. I've tried upping the precision when the digit is "close" to another, e.g. 0x3fff or 0x1000, but cannot find any good definition of "close"; for instance, calculating at digit 9798 gives me 0xcde6 , which is not very close to 0xd000, but the correct digit is 0xd. Can anyone help me figure out how much working precision is needed to calculate a given digit using this algorithm? Thank you,

    Read the article

  • How to make a GRANT persist for a table that's being dropped and re-created?

    - by Eli Courtwright
    I'm on a fairly new project where we're still modifying the design of our Oracle 11g database tables. As such, we drop and re-create our tables fairly often to make sure that our table creation scripts work as expected whenever we make a change. Our database consists of 2 schemas. One schema has some tables with INSERT triggers which cause the data to sometimes be copied into tables in our second schema. This requires us to log into the database with an admin account such as sysdba and GRANT access to the first schema to the necessary tables on the second schema, e.g. GRANT ALL ON schema_two.SomeTable TO schema_one; Our problem is that every time we make a change to our database design and want to drop and re-create our database tables, the access we GRANT-ed to schema_one went away when the table was dropped. Thus, this creates another annoying step wherein we must log in with an admin account to re-GRANT the access every time one of these tables is dropped and re-created. This isn't a huge deal, but I'd love to eliminate as many steps as possible from our development and testing procedures. Is there any way to GRANT access to a table in such a way that the GRANT-ed permissions survive a table being dropped and then re-created? And if this isn't possible, then is there a better way to go about this?

    Read the article

  • Contributing to a Linux distribution

    - by Big Al
    I'm interested in contributing to a Linux distro, but regarding the various distro's developer communities, I'm having a bit of trouble figuring out which one I'd most like to join. What languages I know: C, C++, Lua, Python, and fairly familiar with Perl (though I wouldn't say I "know" it). In particular, I have very little experience with x86 assembly besides hacking stuff together for performance tweaks, though that will be partially rectified soon. What I'm looking for: A community that provides plenty of opportunities for developers to work on various aspects of the distribution. To be honest I'm most interested in reading and working on the kernel source (in which case the distro doesn't matter), but it's pretty daunting and I figure getting into the Linux community and working with experienced Linux developers might give me a better idea of how to jump into the guts(let me know if this is bogus, or if you have any advice regarding that). So... Which distro has the "best" developer community in terms of organization, people who are fun to work with, and opportunities to contribute? I've read various "Contributing to XXX" pages and mailing lists for distros like Ubuntu, OpenSuse, Fedora, etc. but I'd rather get a more personal testament from an actual developer.

    Read the article

  • Detecting duplicate values in a column of a Datatable while traversing through It

    - by Ashish Gupta
    I have a Datatable with Id(guid) and Name(string) columns. I traverse through the data table and run a validation criteria on the Name (say, It should contain only letters and numbers) and then adding the corresponding Id to a List If name passes the validation. Something like below:- List<Guid> validIds=new List<Guid>(); foreach(DataRow row in DataTable1.Rows) { if(IsValid(row["Name"]) { validIds.Add((Guid)row["Id"]); } } In addition to this validation I should also check If the name is not repeating in the whole datatable (even for the case-sensitiveness), If It is repeating, I should not add the corresponding Id in the List. Things I am thinking/have thought about:- 1) I can have another List, check for the "Name" in the same, If It exists, will add the corresponding Guild 2) I cannot use HashSet as that would treat "Test" and "test" as different strings and not duplicates. 3) Take the DataTable to another one where I have the disctict names (this I havent tried and the code might be incorrect, please correct me whereever possible) DataTable dataTableWithDistinctName = new DataTable(); dataTableWithDistinctName.CaseSensitive=true CopiedDataTable=DataTable1.DefaultView.ToTable(true,"Name"); I would loop through the original datatable and check the existence of the "Name" in the CopiedDataTable, If It exists, I wont add the Id to the List. Are there any better and optimum way to achieve the same? I need to always think of performance. Although there are many related questions in SO, I didnt find a problem similar to this. If you could point me to a question similar to this, It would be helpful. Thanks

    Read the article

  • Recursively adding threads to a Java thread pool

    - by Leith
    I am working on a tutorial for my Java concurrency course. The objective is to use thread pools to compute prime numbers in parallel. The design is based on the Sieve of Eratosthenes. It has an array of n bools, where n is the largest integer you are checking, and each element in the array represents one integer. True is prime, false is non prime, and the array is initially all true. A thread pool is used with a fixed number of threads (we are supposed to experiment with the number of threads in the pool and observe the performance). A thread is given a integer multiple to process. The thread then finds the first true element in the array that is not a multiple of thread's integer. The thread then creates a new thread on the thread pool which is given the found number. After a new thread is formed, the existing thread then continues to set all multiples of it's integer in the array to false. The main program thread starts the first thread with the integer '2', and then waits for all spawned threads to finish. It then spits out the prime numbers and the time taken to compute. The issue I have is that the more threads there are in the thread pool, the slower it takes with 1 thread being the fastest. It should be getting faster not slower! All the stuff on the internet about Java thread pools create n worker threads the main thread then wait for all threads to finish. The method I use is recursive as a worker can spawn more worker threads. I would like to know what is going wrong, and if Java thread pools can be used recursively.

    Read the article

  • jquery - radio button not checked on page load, but checked on same function call later

    - by Bill Zimmerman
    Hi, I'm having a strange problem with jquery. When my page loads, I dynamically create some simple radio buttons in a special i've created. However, the default radio button is not checked. It is checked however when the change() event is triggered later, but is never checked the first time. Can someone help? I am certain that the change() event is triggered on the page load, because the rest of the HTML is added dynamically and I can see it. The basic idea is when the page loads, I bind an event handler, and then immediately call it to make sure that the default options are loaded. $(document).ready(function() { $(".options select[name=App]").change(onAppChange); //trigger the change function in the dropdown to populate default options $(".options select[name=App]").change() } Here is the simple onAppChange() function: function onAppChange() { var val = $(this).val(); var app_options = $(this).closest(".options").find(".app_options"); //clear the app_options app_options.empty(); var newOptions = ''; switch(val) { case 'testapp': newOptions='\ <fieldset>\ <legend>TestApp</legend>\ Option 1:\ <label>\ <input type="radio" name="option1" value="value1" checked>\ Value1\ </label>\ \ <label>\ <input type="radio" name="option1" value="value2">\ value2\ </label>\ \ </fieldset>'; break; case 'todo': //for testing newOptions='FOO'; break; } app_options.append(newOptions); } Yes, I am aware that I could use javascript to automatically select a radio button again, but I asked this question because I wanted to understand why this is happening. When using and , there doesn't seem to be any problem. Only with radio buttons. Why does the behavior differ when the same change() event is triggered? What is going on behind the scenes?

    Read the article

  • ntpd on Fedora Core 6 with high negative time rest values

    - by Mark White
    The basic problem is we have a FC6 server instance running on a virtual machine, and the system time seems to have been slowly varying until it is now causing a problem. The server runs 24/7 and has been up for 155 days. It has been changed to show GMT, and reports the time as (example) 00:15:15 GMT whereas the actual time is 00:00:00 GMT. This is an offset of 915 seconds. selinux has been changed to 'setenforce 0' for testing and I am running as root. I stop the ntpd service and change the time in System|Administration|Date & Time. The time still shows the same with 'date' in bash. There are no error logs. I change the date with 'date --set' in bash. The response confirms the changed date. I run 'date' and the incorrect date is shown. There are no error logs. I start the ntpd service and /var/log/messages shows success with 'time reset -915.720139s'. The date remains unchanged. ntpq -p shows three three time servers all have offsets of around -915 seconds. I stop ntpd service and try 'ntpd -gqx' and get the same result as above - success, but a large negative time reset. I've tried varying combinations of the above, and a few more settings in System|Administration|Date & Time - no change. I just need to reset the system time to GMT. No offset. But I can't wait for ntpd to slew the time over the next few weeks. Any advice is welcome, cheers! Sure this shouldn't be this difficult... Mark...

    Read the article

  • Jquery star rating plugin and cancel rating button

    - by Roger
    Using this plugin: http://www.fyneworks.com/jquery/star-rating/#tab-Testing I have a simple callback function that picks up the id from the radio buttons: <input type="radio" class="auto-submit-star {split:2}" id="myid" value="1" /> $('.auto-submit-star').rating({ callback: function(value, link){ alert($(this).attr('id')); } }); This works fine, but if the user clicks on the cancel button, then it can't read the id of it. In the js, I think the cancel button is added dynamically with: control.cancel = $('<div class="rating-cancel"><a title="' + control.cancel + '">' + control.cancelValue + '</a></div>') If I add an id to it like this: control.cancel = $('<div class="rating-cancel"><a id="someid" title="' + control.cancel + '">' + control.cancelValue + '</a></div>') How could I read the id? This would be undefined. I can set a class and use $('.myclass').attr('id') but I will have multiple ratings on one page so I'll need something similar to "this". Or is it possible for the cancel button to pick up the id of the corresponding radio buttons?

    Read the article

  • iPad + OpenGL ES2. Why the Puzzling Virtual Memory Spike During Device Reorientation?

    - by dugla
    I've been spending the afternoon starring at Xcode Instruments memory monitor trying to decipher the following memory issue. I have a fullscreen OpenGL ES2 app running on iPad. I am fanatical about memory issues so my retains/releases are all nicely balanced. I closely monitor memory leaks. My app is basically squeeky clean. Except occassionally when I reorient the device. Portrait to Landscape. Back and forth I rock the device stress testing my discarding and rebuilding of the OpenGL framebuffer. The ambient memory footprint of my app is about 70MB Real Mems and 180MB Virtual Mems. Real memory hardly varies at all during device rotations. However the virtual mems reading sometimes briefly spikes up to 250MB and then recedes back to 180MB. No real pattern. But clearly related discarding/rebuilding the framebuffer. I see random memory warnings in my NSlogs but the app just hums along, no worries. 1) Since iPhone OS devices don't have VM could someone explain to me what the VM reading actually means? 2) My app totally leak free and generally bulletproof dispite the VM spikes. Never crashes. Rock solid. Should I be concerned about this? 3) There is clearly something happening in OpenGL framebuffer land that is causing this but I am using the API in the proper way: paraphrasing: Discarding the framebuffer: glDeleteRenderbuffers(1, &m_colorbuffer); glDeleteFramebuffers(1, &m_framebuffer); Rebuilding the framebuffer: glGenFramebuffers(1, &m_framebuffer); glGenRenderbuffers(1, &m_colorbuffer); Is there some other memory flushing trick I have missed? Thanks for any insight. Cheers, Doug

    Read the article

  • Using datetime float representation as primary key

    - by devanalyst
    From my experience I have learn that using an surrogate INT data type column as primary key esp. an IDENTITY key column offers better performance than using GUID or char/varchar data type column as primary key. I try to use IDENTITY key as primary key wherever possible. But recently I came across a schema where the tables were horizontally partitioned and were managed via a Partitioned view. So the tables could not have an IDENTITY column since that would make the Partitioned View non updatable. One work around for this was to create a dummy 'keygenerator' table with an identity column to generate IDs for primary key. But this would mean having a 'keygenerator' table for each of the Partitioned View. My next thought was to use float as a primary key. The reason is the following key algorithm that I devised DECLARE @KEY FLOAT SET @KEY = CONVERT(FLOAT,GETDATE())/100000.0 SET @KEY = @EMP_ID + @KEY Heres how it works. CONVERT(FLOAT,GETDATE()) gives float representation of current datetime since internally all datetime are represented by SQL as a float value. CONVERT(FLOAT,GETDATE())/100000.0 converts the float representation into complete decimal value i.e. all digits are pushed to right side of ".". @KEY = @EMP_ID + @KEY adds the Employee ID which is an integer to this decimal value. The logic is that the Employee ID is guaranteed to be unique across sessions since an employee cannot connect to an application more than once at the same time. And for the same employee each time a key will be generated the current datetime will be unique. In all an unique key across all employee sessions and across time. So for Emp Ids 11 and 12, I have key values like 12.40046693321566357, 11.40046693542361111 But my concern whether float data type as primary key offer benefits compared to choosing GUID or char/varchar as primary keys. Also important thing is because of partitioning the float column is going to be part of a composite key.

    Read the article

  • java distributed cache for low latency, high availability

    - by Shahbaz
    I've never used distributed caches/DHTs like memcached, jboss cache, ehcache, etc. I'm wondering which, if any, is appropriate for my use. First, I'm not doing web applications (as most of these project seem to be geared towards web apps). I write servers (Order Management Systems actually) for financial trading firms. The servers themselves are not too complicated. They need to receive information (market data, orders, executions, etc.) rout them to their destination while possibly transforming some of these messages. I am looking at these products to solve the following problems: * Safe repository of the state of the server. I'd rather build the logic of my application as a bunch of transformers (similar to Apache Camel) and store the state in a 'safe' place * This repository should be distributed: in case one of these data stores crashes, one or two more should be up and I should be able to switch to them seamlessly * This repository should be fast. Single digits milliseconds count here, in other words, systems which consume/process this data are automated systems, not humans clicking on links. This system needs to have high-throughput and low latency. By sending my data outside the process, I am necessarily slowing performance, but I am trying to balance absolute raw speed and absolute protection of data. * This repository should be safe. Similar to the point about several on-line backups, this system needs to write data to disk (potentially more than one disk). I'd really like to stop writing my own 'transaction servers.' Am I correct to be looking into projects such as jboss cache, ehcache, etc.? Thanks

    Read the article

  • How to temporarily replace one primitive type with another when compiling to different targets in c#

    - by Keith
    How to easily/quickly replace float's for doubles (for example) for compiling to two different targets using these two particular choices of primitive types? Discussion: I have a large amount of c# code under development that I need to compile to alternatively use float, double or decimals depending on the use case of the target assembly. Using something like “class MYNumber : Double” so that it is only necessary to change one line of code does not work as Double is sealed, and obviously there is no #define in C#. Peppering the code with #if #else statements is also not an option, there is just too much supporting Math operators/related code using these particular primitive types. I am at a loss on how to do this apparently simple task, thanks! Edit: Just a quick comment in relation to boxing mentioned in Kyles reply: Unfortunately I need to avoid boxing, mainly since float's are being chosen when maximum speed is required, and decimals when maximum accuracy is the priority (and taking the 20x+ performance hit is acceptable). Boxing would probably rules out decimals as a valid choice and defeat the purpose somewhat. Edit2: For reference, those suggesting generics as a possible answer to this question note that there are many issues which count generics out (at least for our needs). For an overview and further references see Using generics for calculations

    Read the article

  • Improve speed of own debug visualizer for Delphi 2010

    - by netcodecz
    I wrote Delphi debug visualizer for TDataSet to display values of current row, source + screenshot: http://delphi.netcode.cz/text/tdataset-debug-visualizer.aspx . Working good, but very slow. I did some optimalization (how to get fieldnames) but still for only 20 fields takes 10 seconds to show - very bad. Main problem seems to be slow IOTAThread90.Evaluate used by main code shown below, this procedure cost most of time, line with ** about 80% time. FExpression is name of TDataset in code. procedure TDataSetViewerFrame.mFillData; var iCount: Integer; I: Integer; // sw: TStopwatch; s: string; begin // sw := TStopwatch.StartNew; iCount := StrToIntDef(Evaluate(FExpression+'.Fields.Count'), 0); for I := 0 to iCount - 1 do begin s:= s + Format('%s.Fields[%d].FieldName+'',''+', [FExpression, I]); // FFields.Add(Evaluate(Format('%s.Fields[%d].FieldName', [FExpression, I]))); FValues.Add(Evaluate(Format('%s.Fields[%d].Value', [FExpression, I]))); //** end; if s<> '' then Delete(s, length(s)-4, 5); s := Evaluate(s); s:= Copy(s, 2, Length(s) -2); FFields.CommaText := s; { sw.Stop; s := sw.Elapsed; Application.MessageBox(Pchar(s), '');} end; Now I have no idea how to improve performance.

    Read the article

  • Flash movies in inactive browser tabs pause or don't execute in real time

    - by ZenBlender
    I'm noticing some unexpected behavior. Some time in the last few months, a change in either Firefox, the Flash player, or both, has made it so that Flash movies that are in inactive browser tabs no longer execute in real time. They appear to still execute, but only in bursts, and not in a predictable way. This is a problem because I develop a Flash-based (Actionscript 2.0, Flash CS3) multiplayer game that maintains a network connection and allows players to chat, etc. Many of our players complain about Firefox crashing while playing the game. I have noticed it too, not too frequently, but it crashes several times a week. (Firefox crashes, I do not get a message from Flash player that indicates an infinite loop or problem in my code) My theory is that this new behavior is causing crashes when there is a lot of activity in my game, leading to lots of unhandled network traffic for my game getting buffered before Firefox/Flash will give it a chance to execute. Maybe this leads to a buffer overflow or missing packets, and as a result, something crashes. At times I will switch back to the tab that is running my game and discover a display bug, which looks as though Flash has simply failed to execute something that it was supposed to. I would assume this new behavior is on purpose, for example to prevent all the Flash-based advertisements in inactive tabs from executing and therefore killing performance. In a quick test on Chrome (5.0.342.9 beta), this "pausing" of Flash seems to be there as well, but somehow it seems much less of a problem. My users have only complained about Firefox crashing, not other browsers. My machine: Windows 7 x64 Firefox 3.6.3 Flash Player 10.1.50.426 My game: triplejack.com Any ideas? Ideally I'd like to disable this behavior for my Flash game so it can execute in real time even when in an inactive tab. Thanks for any help!

    Read the article

  • DrScheme versus mzscheme: treatment of definitions

    - by speciousfool
    One long term project I have is working through all the exercises of SICP. I noticed something a bit odd with the most recent exercise. I am testing a Huffman encoding tree. When I execute the following code in DrScheme I get the expected result: (a d a b b c a) However, if I execute this same code in mzscheme by calling (load "2.67.scm") or by running mzscheme -f 2.67.scm, it reports: symbols: expected symbols as arguments, given: (leaf D 1) My question is: why? Is it because mzscheme and drscheme use different rules for loading program definitions? The program code is below. ;; Define an encoding tree and a sample message ;; Use the decode procedure to decode the message, and give the result. (define (make-leaf symbol weight) (list 'leaf symbol weight)) (define (leaf? object) (eq? (car object) 'leaf)) (define (symbol-leaf x) (cadr x)) (define (weight-leaf x) (caddr x)) (define (make-code-tree left right) (list left right (append (symbols left) (symbols right)) (+ (weight left) (weight right)))) (define (left-branch tree) (car tree)) (define (right-branch tree) (cadr tree)) (define (symbols tree) (if (leaf? tree) (list (symbol-leaf tree)) (caddr tree))) (define (weight tree) (if (leaf? tree) (weight-leaf tree) (cadddr tree))) (define (decode bits tree) (define (decode-1 bits current-branch) (if (null? bits) '() (let ((next-branch (choose-branch (car bits) current-branch))) (if (leaf? next-branch) (cons (symbol-leaf next-branch) (decode-1 (cdr bits) tree)) (decode-1 (cdr bits) next-branch))))) (decode-1 bits tree)) (define (choose-branch bit branch) (cond ((= bit 0) (left-branch branch)) ((= bit 1) (right-branch branch)) (else (error "bad bit -- CHOOSE-BRANCH" bit)))) (define (test s-exp) (display s-exp) (newline)) (define sample-tree (make-code-tree (make-leaf 'A 4) (make-code-tree (make-leaf 'B 2) (make-code-tree (make-leaf 'D 1) (make-leaf 'C 1))))) (define sample-message '(0 1 1 0 0 1 0 1 0 1 1 1 0)) (test (decode sample-message sample-tree))

    Read the article

  • review count and rating using an image - schema.org

    - by Joel
    I need some help getting some rich snippets to my site I inserted the review microdata following the instructions given on schema.org here http://schema.org/docs/gs.html#advanced_missing using the star-image for rating and the text for review count, but testing it with the test tool it showed nothing. Example page where we use the microdata for the reviews. and here is what I used <div itemprop="reviews" itemscope itemtype="http://schema.org/AggregateRating"> <A HREF="javascript:an();"><img src="/images/stars/4.5.gif" border=0></a> <meta itemprop="ratingValue" content="4.5" /> <meta itemprop="bestRating" content="5" /> <BR><span class="bottomnavfooter"><A HREF="javascript:an();">Read (<span itemprop="ratingCount">70</span>) Reviews</A </span></div> I then created a static test page and made some change using instructions Google provided here http://www.google.com/support/webmasters/bin/answer.py?answer=172705 (which is different from what I found on schema.org!!) but still the test returned only product name not the price or the reviews. Here is my test page - Can you please see where I'm going wrong Thanks much!!

    Read the article

< Previous Page | 740 741 742 743 744 745 746 747 748 749 750 751  | Next Page >