DBM-style Database Abstraction
The DBA functions abstract communications with databases that conform to the style of Berkeley DB database systems. Rather than storing complex records, a DBM database simply stores key/value pairs. This is similar to an associative array.
The functions in this section replace a set of functions that allow just one type of DBM database. These new functions allow for choosing the underlying system from within your PHP code rather than compiling PHP for a single DBM implementation. You choose a type of database when you open a connection, and the rest of the functions perform accordingly. Sascha Schumann added these functions to PHP.
The dba_close function closes a link to a database. The link ...