what is searching engine?

I know different searching method while I was at the university.

is a searching engine store in a huge data base and perform mysql search and move the result to apache server and diplay it with the help of php.


HOW come it can walk in ( crawl ) different sites? what make it jump from one site to the other?


HOW big is goggle in the information that she snatched from the internet?


How many searching engine globally?

Is searching engine equivalent to data-mining?

I'm not sure what this has to do with GNU/Linux, but...

Major search engines like Google and altavista don't use the "standard" PHP+MySQL solution, they usually use programs written in C running on a large cluster of powerful machines, using various database types as the backend. Smaller search engines, like site-specific ones, probably use something like PHP+MySQL or Perl+MySQL or ASP+Access, etc.

They work by fetching pages they already know exist, finding any links to other pages, and adding those new links to their list of pages to fetch. In this way they "crawl" across the Internet. They then keep limited information on each page (the title, url, some keywords, perhaps a little text from the site). Some engines like Google go so far as to keep a copy of the entire page (cache). You can also often submit URLs to search engines, which will be added to their list of pages to fetch. Some "search engines" actually work more like directories, only indexing pages people submit (and often checking each URL individually) and never re-checking them, or only doing os veyr occasionally. These are really web directories.

Google is immense; I've no idea how much information it holds, but I should think it would amount to many more bytes of hard drive space than I could afford in a lifetime Look on their site, they may say there how large they are. There are hundreds of search engines around the world, and they vary in their efficiency, the size of their databases, the types of sites they index, the way you can search them, and the kinds of results you get back.

google doesnt use a standard relational database, they use the older database "engine" that was forgoten about by the world but IBM kept making it better and better as time goes on, i forget the name but its much much faster for extremely large amount of data!.
a comparison of the 2 types of engines are similiar to comparing linux and windows, 1 is easy to setup and functional for home use, the other is harder but once its up its much better as everyone here knows

I used to have a giant paper about the design and structure of google, how it operates on the web, and how it internally processes all that data. If I can find it, I'll let you know what the database system is called. I don't know how big google is, but they keep a running total of indexed pages at the bottom of the main page, and last I new it was over 2.07 billion.