Thanks to everyone who took the time to weigh in on this. Perhaps most useful to me are the comments of those who have used OpenBSD for heavy database work (I intend to use Postgresql) and have gotten satisfactory results.
To Daniel -- I don't think we'll be working for or with each other in the foreseeable future. But I will try to help you understand why I'm taking the approach I am. I'm retired and this work is being done by me and for me; it is not for a client or a company. I don't want to turn it into a big engineering project and proper experimentation would be time-consuming because the database is very large; I want to load it once. I prefer to spend my time doing the things I retired to do. If the project doesn't turn out as well as it might because I didn't engineer it to a fare-thee-well, *I'm* the one who suffers, no one else, and I'm willing to take that chance. I would also point out to you that I never said that I "needed fine locking", which, in fact, I don't know and thus can't say. How could I possibly know that without doing the experiments that I've already said I haven't done? I do thank you, though, for your observations about your own experience with database work on OpenBSD. /Don Allen