Oracle Database Discussions

hello,
I need to create a table that will be a serach engine for keywords in my web site. This table will contains thousands of rows. In order to improve the performance to access to the rows of this table I will create indexes besed on a varchar2 column named keywords.

My problem 's I have to delete, insert on this table evry day because the keywords change day by day, so rebuild my indexes each time i do this action...

My question's there 's another way to improve the perfomance to accesss to this table?
Should I rebuild indexes each time i delete , insert rows?

My database 's Oracle Database 10g Enterprise Edition Release 10.2.0.1.0.
thanks a lot