Initialize an rdf Object
Usage
rdf(
storage = c("memory", "BDB", "sqlite", "postgres", "mysql", "virtuoso"),
host = NULL,
port = NULL,
user = NULL,
password = NULL,
database = NULL,
charset = NULL,
dir = NULL,
dsn = "Local Virtuoso",
name = "rdflib",
new_db = FALSE,
fallback = TRUE
)Arguments
- storage
Storage backend to use; see details
- host
host address for mysql, postgres, or virtuoso storage
- port
port for mysql (mysql storage defaults to mysql standard port, 3306) or postgres (postgres storage defaults to postgres standard port, 4321)
- user
user name for postgres, mysql, or virtuoso
- password
password for postgres, mysql, or virtuoso
- database
name of the database to be created/used
- charset
charset for virtuoso database, if desired
- dir
directory of where to write sqlite or berkeley database.
- dsn
Virtuoso dsn, either "Local Virtuoso" or "Remote Virtuoso"
- name
name for the storage object created. Default is usually fine.
- new_db
logical, default FALSE. Create new database or connect to existing?
- fallback
logical, default TRUE. If requested storage system cannot initialize, should
rdf()fall back on memory (default) or throw an error (fallback=FALSE)?
Details
an rdf Object is a list of class 'rdf', consisting of
three pointers to external C objects managed by the redland library.
These are the world object: basically a top-level pointer for
all RDF models, and a model object: a collection of RDF statements,
and a storage object, indicating how these statements are stored.
rdflib defaults to an in-memory hash-based storage structure.
which should be best for most use cases. For very large triplestores,
disk-based storage will be necessary. Enabling external storage devices
will require additional libraries and custom compiling. See the storage
vignette for details.