SQL performance searching for long strings

Question

I need to store user agent strings in a database for tracking and comparing customer behavior and sales performance between different browsers. A pretty plain user agent str

Answer 1

Your hash idea is sound. I've actually used hashing to speed up some searches on millions of records. A hash index will be quicker since each entry is the same size. md5 will likely be fine in your case and will probably give you the shortest hash length. If you are worried about hash collisions, you can add include the length of the agent string.