Oracle creates nicely HTML-formatted workload reports (AWR) that list things like instance statistics, wait events, the top ten heavy SQL statements (by number of executions, number of disk reads, and so on). Is there a similar tool for Postgresql? ...
I have a website, that is slow-ish. The server responds in around 2 - 300 ms at each request, but it takes 1.5 - 2 seconds for the page to be ready in the browser. By experimenting with disabling javascript and CSS, I have determined that it is the browser's processing, that takes the majority of time. Using Firebug, I see that the D...
Hi, I'm planning to improve the performance of some applications. We generally use factored datahelpers (using System.Data.Common, but we are thinking to specialize some applications that are always going to use sql server. Does anyone know or could test if is increased the performance using specialized classes instead of factorized cl...
Hi! I have an app that's about presenting fictional simplified cities. Please consider the following Django models: class City(models.Model): name = models.CharField(...) ... TYPEGROUP_CHOICES = ( (1, 'basic'), (2, 'extra'), ) class BldgType(models.Model): name = models.CharField(...) group = models.IntegerFi...
When writing simulations my buddy says he likes to try to write the program small enough to fit into cache. Does this have any real meaning? I understand that cache is faster than RAM and the main memory. Is it possible to specify that you want the program to run from cache or at least load the variables into cache? We are writing si...
Assuming you have a hypothetical enum in java like this (purely for demonstration purposes, this isn't code i'm seriously expecting to use): enum Example{ FIRST, SECOND, THIRD, ... LAST; } What's the maximum number of members you could have inside that enum before the compiler stops you? Secondly, is there any per...
This is really strange to me and it's becoming into a real problem. I'm building a site in appengine (java) using scala and It's working really slow when accessed from my domain: /latest 200 1505ms 2325cpu_ms 1586api_cpu_ms 4kb But when accessed from appspot it works much faster: /latest 200 180ms 269cpu_ms 221api_cpu_ms 4kb I've ...
When should I use a composite index in a database? What are the performance ramification by using a composite index)? Why should I use use a composite index? For example, I have a homes table: CREATE TABLE IF NOT EXISTS `homes` ( `home_id` int(10) unsigned NOT NULL auto_increment, `sqft` smallint(5) unsigned NOT NULL, `year_bui...
Python newbie here. Are parts of NumPy and/or SciPy programmed in C/C++? And how does the overhead of calling C from Python compare to the overhead of calling C from Java and/or C#? I'm just wondering if Python is a better option than Java or C# for scientific apps. If I look at the shootouts, Python loses by a huge margin. But I gue...
Hi All, I´m building a series of WCF Services that are going to be used by more than one application. Because of that I´m trying to define a common library to access WCF services. Knowing that each service request made by different users should use a different Channel I´m thinking in cache the Channel per-request (HttpContext.Current.I...
My warehouse datamart data is split across 3 databases on the same server. This is Proof-Of-Concept project with three extracts that were loaded into individual databases. While pulling into a cube, I am essentially doing this: SELECT * FROM DB1.dbo.Fact_Pres UNION SELECT * FROM DB2.dbo.Fact_Pres UNION SELECT * FROM DB3.dbo.Fact_Pres ...
Hi all, With a function a div-popover gets called and filled with dynamic data using Ajax, PHP, MySQL and some HTML/CSS. All goes fine. When I want to delete an entry in the list just popped over it functions as it should. When I send an update request for my list it also goes the way I want it. But, when i call delete(); update(); rig...
I do next: void Foobar(string[] arr, Dictionary<string, string[]>) { var t = arr.Intersect(dic.Keys).ToList(); // .or ToArray() ? foreach(var item in t) { .. } var j = t.Count; // also I need this } which method is preferred? I could go without any but I need to know the size and I don't want to call IEnuramble....
A Java thread is always in one of the following ten states: NEW: Just starting up, i.e., in process of being initialized. NEW_TRANS: Corresponding transition state (not used, included for completness). IN_NATIVE: Running in native code. IN_NATIVE_TRANS: Corresponding transition state. IN_VM: Running in VM. IN_VM_TRANS: Corresponding tra...
I am using the new WPF toolkit's Chart to plot large data sets. I also have a crosshair tracker that follows the mouse when it's over the chart area to tell exactly what is the value of the nearest data point (see Yahoo! Finance charts). I use the following code to find the closest data point that is lower (or equal) to where the mouse ...
I can't guess who is better HttpWebRequest or webclient are you suggest me who is better for performance ...
I have a slow running query that I've been working on optimising. When looking at the Client Statistics in Management Studio it was taking about 8 seconds wait time on server replies and about 1 second on Client processing time. I have always thought that the Wait time on server replies was the number to work on and Client processing t...
I have inherited this sed script snippet that attempts to remove certain empty spaces: s/[\s\t]*|/|/g s/|[\s\t]*/|/g s/[\s] *$//g s/^|/null|/g that operates on a file that is around 1Gb large. This script runs for 2 hours on our unix server. Any ideas how to speed it up? Notes that the \s stands for a space and \t stands for a tab, ...
I have several javascript files that during run-time get combined and minified. This is for an enterprise application with 10+ developers. There are document.ready functions all over the place causing 5+ second javascript load. I'd like more help in figuring out where the bottlenecks are by slowly removing pieces of functionality. E.g. ...
Hi, I am working on a Rails project and hitting a performance problem. Here is the simplified db schema table gaming_platforms ( ~5 rows) id table games ( ~10k rows) id gaming_platform_id winner (black or white or n/a) black_id => online_players.id white_id => online_players.id table onlin...