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 — Elimina una línea en una base DBA
   dba_delete() elimina la entrada
   especificada por la clave key,
   en la base identificada por handle.
  
keyLa clave de la entrada a eliminar.
dbaA Dba\Connection instance, returned by dba_open() or dba_popen().
| Versión | Descripción | 
|---|---|
| 8.4.0 | The dbaparameter expects a Dba\Connection
  instance now; previously, a validdbaresource was expected. | 
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.