[Spambayes] Concurrent DB access leads to corruption? (FAQ question)

[Skip Montanaro]

    Jim>        1. Accessing the database files from more than one process
    Jim>           concurrently.

    Jim> Is this information current?

Yes, I believe it still is.  Most SpamBayes usage scenarios involve just one
of the applications, so there's been no crying need to add locking so they
can operate concurrently.  I think it would be fairly difficult to implement
anyway.  Some apps, like sb_filter, only keep the db open briefly.  Others,
like sb_imapfilter and sb_bnfilter (via it's background server) want to keep
the database open for long periods.  An application waiting on one of these
applications to release the lock would probably need some way to signal the
long-running app to close the database.

    Jim> The cron task could fire at the same time as procmail. Does sb use
    Jim> internal locks to prevent this situation? Is there otherwise a way
    Jim> to avoid corruption with unavoidable concurrent access?

Not that I'm aware of.  Feel free to implement something and toss it back
over the wall. ;-)

Skip