Genezzo Drive Performance

My Clustered Genezzo code is relatively slow because it doesn't use a write-ahead log. Its access pattern involves repeated writes and syncs alternating between blocks at opposite ends of the data file. Potentially it could run much faster on a solid-state drive. I tested the performance of inserting 1000 integers into a table, with a commit after each insert. I avoided SQL to eliminate Perl Parse::RecDescent overhead. I tested a internal SATA drive, a Coraid ATA-over-Ethernet SAN drive on 100Mbit ethernet, and a SanDisk USB 2.0 ("keychain") flash drive. The system monitor showed the internal SATA drive test was CPU-limited, while the ATA-over-Ethernet SAN drive test was network-limited. I also tested base Genezzo without Genezzo::Contrib::Clustered enabled. Base Genezzo also lacks a write-ahead log, but performs fewer syncs per commit and fewer widely-spaced writes. All tests were done on 500M databases, except for Genezzo::Contrib::Clustered on flash which used the default 600K (?) size. With a 500M database the flash test using Genezzo::Contrib::Clustered got 3 commits per second; this requires further investigation...

Updated Clustered Genezzo on CPAN

Revision 0.34 of Genezzo-Contrib-Clustered has been posted on CPAN. One module moved, one test fixed.