The Josh Blog search engine works by doing a fulltext search on two fields of the database that runs everything. One is the field containing the entries you usually read, and one is a reference field that you don't normally see. Ideally this means that you can find entries pertaining to, say, the Dismemberment Plan, which don't actually mention the Plan in the entry text - that information is hidden away in the references. Unfortunately, I haven't been keeping good references since Josh Blog moved to ellipsis. In the coming month I hope to go back and put in at least some of the obvious references so that the search is more useful.
Remember that currently this only searches on entries made since August 2001. Moving entries from my old archives into the newfangled database is a long-term project.
Because of the way the search works, it may return some entries which seem less than perfectly relevant. Consider this a feature: by searching you'll also grab other interesting entries which may be tangentially related (at best).
The minimum word length currently searched on is 4 characters. This may change to 3 to include words like "rap".
The following information about search options and example searches was stolen from the MySQL documentation.
Boolean fulltext search supports the following operators:
And here are some examples:
+apple +(>pie <strudel)