[Python-3000] Nonlinearity in dbm.ndbm?

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    Josiah> The version I just posted to the tracker reads/writes about 30k
    Josiah> entries/second.  You may want to look at the differences (looks
    Josiah> to be due to your lack of a primary key/index).

    me> Thanks.  The real speedup was to avoid using cursors.

Let me take another stab at this.  My __setitem__ looks like this:

    def __setitem__(self, key, val):
        c = self._conn.cursor()
        c.execute("replace into dict"
                  " (key, value) values (?, ?)", (key, val))
        self._conn.commit()

This works (tests pass), but is slow (23-25 msec per loop).  If I change it
to this:

    def __setitem__(self, key, val):
        self._conn.execute("replace into dict"
                           " (key, value) values (?, ?)", (key, val))

which is essentially your __setitem__ without the type checks on the key and
value, it runs much faster (about 300 usec per loop), but the unit tests
fail.  This also works:

    def __setitem__(self, key, val):
        self._conn.execute("replace into dict"
                           " (key, value) values (?, ?)", (key, val))
        self._conn.commit()

I think you need the commits and have to suffer with the speed penalty.

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