Rational use of antibiotics to treat respiratory tract infections

An apparatus and method to significantly improve performance of SQL function processing through the use of an encoded vector index (EVI). An EVI provides the data necessary to count the number of records in a database that match criteria provided by a SQL function. The resulting count can then be used to determine, from among two or more candidate approaches, an approach to use in processing an SQL function. By processing the EVI symbol table in lieu of more traditional database indexes, and/or in lieu of the database table itself, statistics for SQL functions are generated significantly faster.