This section evaluates the performance of Rhino. All measurements were carried out on a DEC Alphastation 250 with a 21064A CPU running at 266MHz, 47MB of user memory, and a DEC RZ26L 1GB SCSI disk.
We compared five systems: the three versions of Rhino running on SPIN, the page diffing version of Rhino running on Digital UNIX 3.2, and ObjectStore 4.0 running on Digital UNIX 3.2 [odi].
Rhino on Digital UNIX uses the same page diffing code to detect modifications, but buffers are on ordinary virtual memory pages instead of a memory-mapped file, and page faults are detected using UNIX signals. Digital UNIX Rhino was measured to quantify the benefits of SPIN's extension architecture, which allows low-cost communication between extensions and the kernel.
ObjectStore is a client-server database management system that buffers database contents on a client's virtual memory. It implements no-steal, no-force buffer management and page grain logging. ObjectStore is included to compare Rhino against a state-of-the-art, object-oriented database system.
We first present the micro-benchmarks that show the latency of the critical paths. Next, we present results from two benchmarks, RVM [rvm] and OO7 [oo7]. The RVM benchmark typifies small update transactions, while OO7 typifies graphical CAD database operations.