I've got a users table and a votes table. The votes table stores votes toward other users. And for better or worse, a single row in the votes table, stores the votes in both directions between the two users. Now, the problem is when I wanna list for example all people someone has voted on. I'm no MySQL expert, but from what I've figure...
Hi! I'm facing a really strange problem with a .Net service. I developed a multithreaded x64 windows service. I tested this service in a x64 server with 8 cores. The performance was great! Now I moved the service to a production server (x64 - 32 cores). During the tests I found out the performance is, at least, 10 times worst than i...
We all know that $a1 = array('foo'); $a2 = $a1; $a2[0] = 'bar'; // now $a1[0] is foo, and $a2[0] is bar. The array is copied However, what I remember reading, but cannot confirm by Googling, is that the array is, internally, not copied until it is modified. $a1 = array('foo'); $a2 = $a1; // <-- this should make a copy // but $a1 and ...
I'am interested in some data gathering about requests per second (the definition of requests per second i use is 'a user requests a certain functionality provided by an URL' (this means requests != hits (one request may consist of multiple hits))). So how many requests per second and server do you serve? If you dont maintain your own app...
Following on from http://stackoverflow.com/questions/53738/how-do-you-test-the-performance-of-a-website : What tools/sites/services do you use to find out the performance of your website from multiple locations around the world? There are always complaints that sites are slow under certain circumstances (especially from physically-di...
CDNs seem like a tremendously brute-force approach to improving website performance across the world, since they use some thousands of machines close to the end-user to ensure good throughput. Are there any ways of improving performance over long distances with high latency or slow-ish links (e.g., UK to Australia) over the "usual" meth...
I have a table-valued, inline UDF. I want to filter the results of that UDF to get one particular value. When I specify the filter using a constant parameter, everything is great and performance is almost instantaneous. When I specify the filter using a variable parameter, it takes a significantly larger chunk of time, on the order of...
using System; using System.IO; using System.Reflection; using System.Text.RegularExpressions; namespace regex { class MainClass { public static void Main(string[] args) { Regex exp = new Regex(@"e(-)?m[a@]il(s)?|input|output|padr(ão|ões)|máquina(s)?|reconhecimento", RegexOptions.IgnoreCase |...
We have a database with a generous use of the CLOB/TEXT datatype all over the schema. After running lots of queries yesterday on multiple tables having a CLOB type, I came to the conclusion that as soon as there is a CLOB in the SELECT clause (even if the value if NULL/empty), the query takes a huge performance hit. We have a client-ser...
We just implemented a drupal site. Performance of the site seems to be an issue. We enabled drupal caching, set up apache caching derivates. Repeated page visits are fast enough (coz CSS and JS are cached), but initial page visits are still a problem. Drupal experts, could you offer us some pointers, on different techniques used to s...
I'm just curious and can't find the answer anywhere. Usually, we use an integer for a counter in a loop, e.g. in C/C++: for (int i=0; i<100; ++i) But we can also use a short integer or even a char. My question is: Does it change the performance? It's a few bytes less so the memory savings are negligible. It just intrigues me if I do a...
Q: How do I calculate the total time it takes to render an MVC page and display the time on the master page. In Asp.net Web Form I created a Base page class like so: public class PageBase : System.Web.UI.Page { private DateTime startTime = DateTime.Now; private TimeSpan renderTime; public DateTime StartTime { ...
Does anyone know of a quick-starting Haskell interpreter that would be suitable for use in writing shell scripts? Running 'hello world' using Hugs took 400ms on my old laptop and takes 300ms on my current Thinkpad X300. That's too slow for instantaneous response. Times with GHCi are similar. Functional languages don't have to be slow...
Our database architecture consists of two Sql Server 2005 servers each with an instance of the same database structure: one for all reads, and one for all writes. We use transactional replication to keep the read database up-to-date. The two servers are very high-spec indeed (the write server has 32GB of RAM), and are connected via a f...
When using a Guid as an index for a Dictionary, is it better to use the Guid object, or the string representation of the Guid? I just refactored some code which was using string to use the object, because there were new Guid() calls all over the place. But that left me wondering what the performance issues might be. (The collections are...
Our server application receives information about rows to add to the database at a rate of 1000-2000 rows per second, all day long. There are two mutually-exclusive columns in the table that uniquely identify a row: one is a numeric identifier called 'tag' and the other is a 50character string called 'longTag'. A row can have either a ...
I'm using Javascript to parse an XML file with about 3,500 elements. I'm using a jQuery "each" function, but I could use any form of loop. The problem is that the browser freezes for a few seconds while the loop executes. What's the best way to stop freezing the browser without slowing the code down too much? $(xmlDoc).find("Object"...
I have a table with roughly 100.000 blog postings, linked to a table with 50 feeds via an 1:n relationship. When I query both tables with a select statement, ordered by a datetime field of the postings table, MySQL always uses filesort, resulting in very slow query times (>1 second). Here's the schema of the postings table (simplified): ...
I am trying to profile and optimize algorithms and I would like to understand the specific impact of the caches on various processors. For recent Intel x86 processors (e.g. Q9300), it is very hard to find detailed information about cache structure. In particular, most web sites (including Intel.com) that post processor specs do not inc...
In my project one download button is there . if user download button click then i will show count of download . is it possiable have any module for download hit counter ? ...