python+sqlite3 in memory database

[Benjamin Peterson]

John Nagle <nagle <at> animats.com> writes:
>     "sqlite" has reasonably good SELECT performance on simple indices,
> but anything beyond that isn't all that great.  Multiple processes
> updating the same sqlite database will have terrible performance,
> because the locking mechanism not only locks the entire table,
> the wait mechanism is a timed retry.

This is been improved significantly in recent versions with support for write
ahead logging and different lock levels to prevent writer starvation.