For AFIS projects for duplicates search in large databases
Searching for duplicates in a biometric templates database is a task that requires to perform many computations, as each biometric template needs to be verified with each other template in the database.
This task has a quadratic complexity:
if a templates’ database becomes two times bigger, the duplicates search needs four times more computations; a three times bigger database needs nine times more computations, and so on. In other words, it will either take four times more time for deduplicating this double-size database, or it will require four times faster hardware to preserve the same search time.