Commonly a regular path in your filesystem.
It is r
for read access, w
for
read/write access to an already existing database, c
for read/write access and database creation if it doesn't currently exist,
and n
for create, truncate and read/write access.
The name of the handler which shall be used for accessing path. It is passed all optional parameters given to dba_popen() and can act on behalf of them.