How Hard Is It To Write Your Own Search Engine?
kha0z writes "Anna Patterson, from Stanford University, overviews the difficulties that have to be overcome when attempting to develop and/or implement a search engine solution in this article in the ACM Queue Magazine. The article covers many issues dealing from data sources, to indexing, to ranking. How does Google make it look so easy?"
For a overview of the field that is full-text search (of which web search engines is an important, but not the only, part), you should read Tim Bray's essays on search. He's been working on full-text search for a long time, knows his stuff and explains it in a very readable manner.