rdf {rdflib}

Initialize an rdf Object

Description

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.

Value

an rdf object

Examples

x <- rdf()