rdf
ObjectInitialize an rdf
Object
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
)
an rdf object
Storage backend to use; see details
host address for mysql, postgres, or virtuoso storage
port for mysql (mysql storage defaults to mysql standard port, 3306) or postgres (postgres storage defaults to postgres standard port, 4321)
user name for postgres, mysql, or virtuoso
password for postgres, mysql, or virtuoso
name of the database to be created/used
charset for virtuoso database, if desired
directory of where to write sqlite or berkeley database.
Virtuoso dsn, either "Local Virtuoso" or "Remote Virtuoso"
name for the storage object created. Default is usually fine.
logical, default FALSE. Create new database or connect to existing?
logical, default TRUE. If requested storage system cannot initialize,
should rdf()
fall back on memory (default) or throw an error (fallback=FALSE)?
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.