Maybe I am day-dreaming but I am about to merge the contents of two large tables which represent two companies versions of the same data. I'd like to avoid duplicates (entries with the "title" field from DB 1 being almost the same as the "title" from DB 2. Are there any methods in php or mysql do do close string matches and return a relevance factor? Or any good php classes anyone knows of to check for likeness?
Try the levenstein function in PHP.
In MySQL you will have to write stored procedure for that.