Are there any differences in performance or load/caching behavior when displaying images in img tags vs divs with image backgrounds? My example: I have a site with many overlapping images, some of which I will need to load dynamically with javascript. One issue is that I need to anchor the images to the right of the element, so that...
I am working on a Google Maps-like scrolling/panning system. The system is supposed to be a lot simpler than the "original" (no zooming) and as such is built in a quite straight forward fashion: There is a containing div representing the viewport with overflow set to hidden and a fixed size This div contains another div that's being pa...
The profilers I have experience with (mainly the Digital Mars D profiler that comes w/ the compiler) seem to massively slow down the execution of the program being profiled. This has a major effect on my willingness to use a profiler, as it makes profiling a "real" run of a lot of my programs, as opposed to testing on a very small input...
Hello, I'm using Access 2007. I have a query that accesses a table with a few hundred thousand records in it, which I am joining to another table via an inner join based on two fields. The joining fields are indexed in both tables, and the sort column is also indexed. When I run the query straight up, the result set opens up in about...
Assuming an ideal situation: nothing is paged out, all code is really well written and fits in cache, the scheduler never interrupts you, etc.: can a single core in a multi-core CPU generate enough write traffic to saturate the IO bus to the DIMMs? In a more concrete form: If I were to launch a program that does a 16GB memset in one thr...
Hi again everybody, Similar to my last question, I'd like to have a PHP function that can take a local path and tell me (a) how much the total file size is for HTML, CSS, JS and images, and (b) the total load time for this page. Like YSlow I think, but as a PHP function. Any thoughts? I looked around and was wondering can I use CURL ...
i need a way to check my websites performance for more than at least a 100,000 hits per day. I dont want to be caught offguard during spikes of visitors to the website. So is there any way i can check for website performance. any scripts, programs software which i can use for offline/online testing ? ...
I have an application where I need to retrieve a large amount of rows from the database and then print them all on the screen. I've checked the mysql queries, and that's not where the problem is. The problem is the rows all need to be printed on the same page, with no pagination, and it takes a long time (I'm talking about a table with s...
I have a question about equivalent search result, that can occur on different fields. Let's say I record the logical deletion state of records with 3 fields like : Boolean Deleted Date DeleteDate String DeleteUserName The goal of the query is to avoid having deleted records into my selection. So I can search the first field with on...
Hi there. I have a page with a jstree and/or jqgrid - it really doesn't matter which one I use to show my point, as I suspect it's any hover effect in IE8... Back to point: When hovering over an <a> tag the background-color is changed with CSS. In all browsers, including IE7 (although slightly slower - I'd guess +-300ms) there is no la...
Just to clarify it's not actually my database and I didn't choose access, I'm just helping a company out by developing some of their already implemented access database. Anyway, on some of their forms the forms open and run extremely slowly for no apparent reason. There is one form which takes a long long time to open on everyone's comp...
Hello, I have the following tables: Products Categories Subcategories Brands with the following fields: Products: id name description1 description2 description3 id_category id_subcategory id_brand Categories: id name Subcategories id name Brands id name What I want is to make a query, where the user inputs 1 or more...
When deciding to use a specific container (List/Set/Map), I like to consider the performance (big-Oh notation) metrics of operations such as insert, delete, get, etc. This is so I can select the best container for my needs. The API docs always specify synchronized/unsynchronized, but not other performance metrics. Is there a table of r...
We are testing our software for the first time on a machine with > 12 cores for scalability and we are encountering a nasty drop in performance after the 12th thread is added. After spending a couple days on this, we are stumped regarding what to try next. The test system is a dual Opteron 6174 (2x12 cores) with 16 GB of memory, Windows...
I have some code in a thread. The code's main function is to call other methods, which write stuff to a SQL database like this: private void doWriteToDb() { while (true) { try { if (q.Count == 0) qFlag.WaitOne(); PFDbItem dbItem = null; lock (qL...
Scenario: Client C connects to Server S via RMI C asks S to create a handler H, S returns H to C C then talks to H Now I could do this in two ways: Make the handler a Remote and let S return the stub to it, so C can directly talk to that (h.say(String msg);) Give the handler an ID and return that to C. C will talk to H via S (s.say...
Suppose I have an application written in native C++ (over 500k lines of code) and I want to port it to .NET (C#). One thing I'm worried about is the JIT compiler. It takes my native code compiler over 30 seconds to compile. Does that mean that each time the user starts my C# app, it's going to take that long just to load it (since the JI...
Hi Guys, I have a PHP application that for every request loads 1 ini file, and at least 10 PHP files. As these same files are loaded for every single request I thought about mounting them on a ram disk but I have been told that the linux filing system (ext3) will basically cache them in some way that a ram disk would not improve perfor...
I have a static large array-of-arrays, witch represents tree structure with about ~100k nodes, this array is only read-only reference for value lockups. Now, witch of this methods will perform better? First, simply array definition in pure PHP file, for including in requests Second, serialize this array, gzip serialized output, and lo...
Ok, I've got a real head scratcher... I'm going bald! This is a pretty simple problem. Inserting data into the table normally works fine, except for a few times, the insert query takes a few seconds. This isn't very good, so I setup a simulation of the insert process. I am NOT trying to bulk insert data. I am trying to find out why...