Re: back-bdb online indexing

[Howard Chu <hyc@symas.com>]

Stop me if you think I'm getting carried away...

We can actually do a complete close / reopen of the backend here. This 
might be something you'd want to do if you've edited some DB_CONFIG 
settings and want them to take effect immediately. Or, if you change the 
olcDbDirectory to point at a new path, you can swap out the entire 
database environment on the fly. So far I've found no memory leaks from 
calling bdb_db_close / db_open, so this looks like a pretty safe thing 
to do. This gives us one of the benefits that was originally brought up 
in the GentleHUP discussions, being able to completely replace one 
database with another without halting the server.

The catch (there's always a catch) is that it may be a very slow process 
to flush one environment and load the next, and the server will be 
unable to process any queries for that suffix until the db_open completes.

--
 -- Howard Chu
 Chief Architect, Symas Corp.       Director, Highland Sun
 http://www.symas.com               http://highlandsun.com/hyc
 Symas: Premier OpenSource Development and Support