The Katapayadi formula and the modern hashing technique

The essence of the modern hashing technique in computer science is the derivation of a number from a nonnumeric key to index into a table where the record containing the key is stored. In this paper, an interestingly similar technique used in South Indian musicology in the 18th century is described, and the question of whether it is an anticipation of the hashing technique is briefly addressed. The problem of retrieving a record from a table based upon a given key has been studied extensively. In this paper, I describe one particular approach to this problem-hashing-and also an interesting earlier development very similar to it. It is generally believed that the idea of hashing was originated by H.P. Luhn (1953), and first described in the open literature by A.I. Dumey (1956), but is it possible that the Katapayadi scheme of deriving numbers from names-in conjunction with the applications to which it had been put, especially in classical South Indian musicology-is an early anticipation of the hashing technique? I discuss this issue in detail in this paper