On August 3, 2002 12:54 am, Jason Stechschulte wrote: > On Sat, Aug 03, 2002 at 01:49:10AM -0300, Manuel Lemos wrote: > > >Google has 1 billion pages and qurys in a few milliseconds... > > > > Real search engines do not use SQL databases. > > What do search engines use? Is there something out there that explains > how they work?
Generally search egines use various hash algorithms to store their data, such as B-trees, Hash Tables, etc... Even that, is not enough when dealing with an extremely large dataset, in which case expensive hardware is used to provide the necessary IO capacity to allow for fast look ups. If you are trully interested in how search engines do this, there are plenty of articles describing Google's setup in terms of hardware. As far as fetching data from large MySQL databases it is not impossible or slow as some people claim. I have a 4 million record database in MySQL that is routinely accessed and most queries on that table are completed in 0.01-0.03 seconds, speed mostly depending on the number of rows retrieved. Keep in mind that your system and database configuration will play a very large role in regard to performance once you go beyond a certain amount of data. -- Ilia Alshanetsky [EMAIL PROTECTED] http://fud.prohost.org/forum/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
