It presents a main contact screen or blank user-definable fields. You enter words, numbers or dates in the field you want searched. Better SA programs let you carry-out concurrent multiple searches. Assuming all needed information is in your SA program, some packages let you enter all 4 criteria and do a one pass search through the database. Be cautious with programs that require you to learn boolean logic for searches.
Boolean logic is a programming process for doing multilevel searches.
It's not easy to learn and if not used regularly, easily forgotten. Speed can be effected by a number of things including programming language, program design, underlying file handling utility, etc. You don't want your field sales person or telemarketer waiting minutes every time they need to search for the next record. Look for SA programs that use fast file structures and file handling routines. Generally, a D-base file is accessed or tranferred more slowly than a file using a file handling utility like btrieve from Novell.