experimental QDBM TXN patch

[Matthias Andree]

Stefan Bellon <sbellon at sbellon.de> writes:

> That's working. However it is _so_ slow compared to the non-txn
> version,

One more thing:

QDBM transactions are only used for write access, so I can think of
exactly one thing that causes a massive slowdown in regular operation:
bogofilter running with the -u switch.

The -u switch requires the database to be opened in write mode and,
depending on how QDBM handles its locking internally, can cause massive
locking contention in addition to that, besides the synchronous writes
that data base operations entail anyway.

-- 
Matthias Andree