Note that the memory is lost after doing this. If you had a key 'foo' with a value of 1000 bytes, that 1000 bytes is lost, and the DB file size will reflect this.
(PHP 4, PHP 5, PHP 7, PHP 8)
dba_delete — Delete DBA entry specified by key
$key, resource $dba): booldba_delete() deletes the specified entry from the database.
keyThe key of the entry which is deleted.
dbaThe database handler, returned by dba_open() or dba_popen().
成功时返回 true， 或者在失败时返回 false。
Note that the memory is lost after doing this. If you had a key 'foo' with a value of 1000 bytes, that 1000 bytes is lost, and the DB file size will reflect this.