rdf_attach_db(+Directory, +Options) is det
Start persistent operations using Directory as place to store files. There are several cases:

Options:

access(+AccessMode)
One of auto (default), read_write or read_only. Read-only access implies that the RDF store is not locked. It is read at startup and all modifications to the data are temporary. The default auto mode is read_write if the directory is writeable and the lock can be acquired. Otherwise it reverts to read_only.
concurrency(+Jobs)
Number of threads to use for loading the initial database. If not provided it is the number of CPUs as optained from the flag cpu_count.
max_open_journals(+Count)
Maximum number of journals kept open. If not provided, the default is 10. See limit_fd_pool/0.
directory_levels(+Count)
Number of levels of intermediate directories for storing the graph files. Default is 2.
silent(+BoolOrBrief)
If true (default false), do not print informational messages. Finally, if brief it will show minimal feedback.
log_nested_transactions(+Boolean)
If true, nested log transactions are added to the journal information. By default (false), no log-term is added for nested transactions.\\
Errors
- existence_error(source_sink, Directory)
- permission_error(write, directory, Directory)