I'm not sure whether it will be interesting for you, but - take a look at Oracle Text.
Originally Posted by Oracle
Oracle Text is a tool that enables you to build text query applications and document classification applications. Oracle Text provides indexing, word and theme searching, and viewing capabilities for text.
Anyway, Oracle Text exists in 10g as well - you'd see a link to it if you had read a little bit more than just the very first line at the provided page, right in the "Technical Overviews by Version" section. Or, search for it by yourself (that's even better option).