I'm having a little trouble with approaching a database searching problem. Lets say I have a database abstraction layer that I plan to work with Mysql, Sqlite, Access, Oracle, etc. In addition, I need to search through the TEXT fields. These records could be huge, like posts you might see on a forums board. What is the best way to design a solution that will let me search (the most efficient way) through huge text records, but might be in mysql, sqlite, etc?
I have a sql class that lets me do queries and takes into account for differences between some database systems (like with "limit" and "like"). I could create a function that would return a link to a resource with the records. How different are major database sytems with indexing the text fields?