Compare between the similarity of rows

Hi All

I am trying to implement program that enable me to in a database and sort them based on the similarity degree of records.

The normal solution is based on pairwise comparison where you need to compare records against each other. This solution has very time complexity. Therefore, I am wondering if there is any other algorithms that you suggest to solving this problem in very fast and efficient way.

Thank you very much in advance and I look forward to hearing from you.