I'm trying to work out how to efficiently sort a huge dataset that won't fit in memory. The obvious answer at a high level is to sort a whole bunch of chunks that do fit in memory using some standard algorithm, write these out to disk, and then merge them. Merging them is the problem. Let's say the data divides up into C chunks, so I ...
My manager wants to know the speed of our website and its load times in different locations of the world, according to some speed testing websites / tools. What are the standard tools / procedures for this? Please help, this is urgent. Thanks. ...
Everyone probably knows the code to run a program and wait for it to end: CreateProcess(... WaitForSingleObject(Process.hProcess, INFINITE It was used several times by myself. But recently I found that this call when it launches a program with a multimedia playback has worse performance than the same process being executed from ...
I'm trying to figure out how to correctly use Java's Executors. I realize submitting tasks to an ExecutorService has its own overhead. However, I'm surprised to see it is as high as it is. My program needs to process huge amount of data (stock market data) with as low latency as possible. Most of the calculations are fairly simple ar...
Hello everyone, just want to ask for an opinion regarding mysql. which one is the better solution? case1: store in 1 row:- product_id:1 attribute_id:1,2,3 when I retreive out the data, I split the string by ',' I saw some database, the store the data in this way, the record is a product, the column is stored product attribute: a:3...
Hi, Say I have a dual-core windows laptop and I run a multithreaded application on it. Does the JVM run only on one core or do the JVM and the OS somehow communicate to split threads between the two cores? A similar question has been asked for C#. I've also had a look into a couple of Sun's performance white papers. I read that threads...
I need to build a web application with different process flows and different UI steps depending on the locale of the logged in user. I have developed a number of ASP.NET applications in C# and like the separation of concerns an MVC approach would give me. So I am looking at using these technologies. The kicker is that different user...
I have a container similar to this one. template <typename Nat, typename Elt> class NatMap { public: Elt& operator[] (Nat nat) { return tab [nat.GetRaw()]; } private: Elt tab [Nat::kBound]; }; I wanted to drop the requirement for Elt to have a default constructor: template <typename Nat, typename Elt> class NatMap { pub...
the title says it all. i noticed that serialization as well des deserialization takes 10x as lang with protobuf-net compared to XmlSerializer. the output files however are much smaller. i find this confusing because protobuf is such a simple format that should run very fast. any hints on how to speed it are greatly appreciated. Edit: h...
I have a SearchController with an action that can execute some long running searches and return a results page. The searches can take anywhere from 1 to 60 seconds. The URL for a search is an HTTP GET request of the form: http://localhost/Search?my=query&is=fancy The experience I'm looking for is similar to the many travel sites t...
I was given some code in which some of the parameters are pointers, and then the pointers are dereferenced to provide values. I was concerned that the pointer dereferencing would cost cycles, but after looking at a previous StackOverflow article: http://stackoverflow.com/questions/431469/how-expensive-is-it-to-dereference-a-pointer-in-c...
My supervisor told me this query will 'crash the server' (because it has millions of tables i believe). Can anyone tell me WHY? maybe show me the way i am suppose to do it? I am currently reading manuals to figure this out. What i was told is these joins are to slow. What is slow about it? "JOIN A AS o ON a.A =aa.A " . "JOIN B AS...
I have a question about how to make marquee text smooth (using Qt 4.5.3) on not powerful hardware (Atom N270 + Intel 945GSM). My approach is as follows: I draw my text (36px Arial bold) onto a QPixmap (off-screen paint device) I set a timer to shift 1px content to left in each 30ms. When onTimer event is triggered, I make a selection...
I've two master tables Org & Item and then there's an OrgItem table.I have to fetch ItemCodes for a particular Org. TABLE STRUCTURE: Org ( Id, OrgCode, Name) - Org Master table Item ( Id, ItemCode, Name) - Item Master table OrgItem ( ItemId, OrgId, ItemCode) - Some Org specific ItemCodes Now only some Item's have Org specific Item...
The Performance Golden Rule from Yahoo's performance best practices is: 80-90% of the end-user response time is spent downloading all the components in the page: images, stylesheets, scripts, Flash, etc. This means that when I'm developing on my local webserver it's hard to get an accurate idea of what the end user will exper...
I'm developing an application which make use of display lists offered by OpenGL. My idea is to call display lists for a repeatitive tasks, such as tranformations and server state sets. Actually the implementation allow two display lists per renderable object. In these two cases display lists doesn't contains vertices, normals etc., but o...
There are many MD5 JavaScript implementations out there. Does anybody know which one is the most advanced, most bugfixed and fastest? I need it for this tool: http://www.bruechner.de/md5file/js/ ...
This consists of two questions: Is MySQL's timestamp field really faster than datetime field in "order by" query? If the answer to above question is yes, how much faster it could be? Supposed in a table of 100 million rows and frequently sort a bunch of 100-200k rows based on timestamp field inside MySQL, will the sort time improvement...
Hi guys Now the machines we are forced to use are 2GB Ram, Intel Core 2 Duo E6850 @ 3GHz CPU... The policy within the company is that everyone has the same computer no matter what and that they are on a 3 year refresh cycle... Meaning I will have this machine for the next 2 years... :S We have been complaining like crazy but they said...
Here is code of very simple expression evaluator using IronRuby public class BasicRubyExpressionEvaluator { ScriptEngine engine; ScriptScope scope; public Exception LastException { get; set; } private static readonly Dictionary<string, ScriptSource> parserCache = new Dictionary<string, ScriptSource>(); public BasicRubyExpressio...