2 Scalability

Depending on the OS and further application restrictions, the SWI-Prolog RDF stores scales to about 15 million triples on 32-bit hardware. On 64-bit hardware, the scalability is limited by the amount of physical memory, allowing for approximately 4 million triples per gigabyte. The other limiting factor for practical use is the time required to load data and/or restore the database from the persistent file backup. Performance depends highly on hardware, concurrent performance and whether or not the data is spread over multiple (named) graphs that can be loaded in parallel. Restoring over 20 million triples per minute is feasible on medium hardware (Intel i7/2600 running Ubuntu 12.10).