If I have a table: CREATE TABLE film ( title CHAR(200) NOT NULL, INDEX title_index (title(5)) ); What is the underlaying reason why it is faster to index only a prefix of the title? Is it always faster? even if i have a trillions of title 200 characters long? what should i think of when deciding of the prefixes' length? thanks! --- Daniel Åkerud [ Don't underestimate the power of stupid people in large groups]