2010/4/21 Torsten Förtsch <torsten.foert...@gmx.net>: > The mmapdb databases (single files) can be prepared off-line and then be > copied to the destination. Then the old database (still mapped by its users) > is invalidated by setting a flag. At the time of the next access the new > version will be mmapped. MMapDB is completely lock-free. So, deadlocks as with > BerkeleyDB cannot occur.
Actually, this is the same approach I would use with BerkekelyDB: build the database offline, watch for a newer file in a directory, switch to the new one when it arrives. This is a read-only application, so there's no need for locks at all. In both cases you have the same drawback: it's impossible to read anything from the shared data without copying the data you read into perl variables. A shared database only saves memory if you don't need all of the data to handle a request. - Perrin
