Learning by doing

I am so behind the times ... NHibernate 2.0.1 GA was released last fall and 2.1.0 Alphas are coming out. In the mean time, Hibernate.org has been subsumed by Redhat's JBoss. The url www.hibernate.org doesn't take you anywhere useful, and following the javascript menu to projects / services / hibernate still doesn't get you anywhere - pure garbage. It is clear that JBoss wants to sell you their enterprise build of Hibernate instead (that "Products" link works). I have been so busy with my day job that I haven't been keeping up. I work at a hospital, supporting Cerner Millenium - writing CCL, Perl, Python, Microsoft SQL (occasionally), and a bit of C#. Cerner CCL is a proprietary language that feels like a mash-up of Fortran IV and and an arcane dialect of SQL from 1976. The language used to run on VMS servers, but we have migrated to HP-UX, and I am OVERJOYED to have a choice of using a posix shell, ksh or csh. Also, I recently discovered that CCL al...

Google has donated Hibernate Shards - a Java 5 add-on to Hibernate that allows application driven data partitioning with your custom or their pre-build configurations. One thing that caught my eye was that when they covered partitioned Native ID generation (aka Identity), they mentioned having Database A use a range 0-200000, Database B use range 200001 - 400000, etc. I know that MySQL cluster suggests using something like this: Database A: Starting ID 1, Increment ID by 3 (number of databases) Database B: Starting ID 2, Increment ID by 3 Database C: Starting ID 3, Increment ID by 3 This allows a hands-off approach, and easily lets you divide ID by 3 and use the remainder to map to a "Shard". Of course, if your data changes significantly, you may have to dump and reload to add another database. One way to avoid a dump and reload is to pick an increment that is larger than your actual database count, and just drop an extra database in an the available Starting ID. This ...