Gregory (Grisha) Trubetskoy wrote:
On Fri, 17 Jun 2005, Jim Gallacher wrote:
**** Brain Wave ****
It just occured to me that the performance problem may be related to
opening and closing the dbm file for every record insertion. Adjusting
the test so that the file is only opened once, I get O(1), and a great
speed boost: 0.2 seconds / per 1000 records all the way up to 50,000
records. At that point I start to see period performance hits due to
disk syncing, but that is to be expected.
I have no idea what to do with this knowledge unless we can figure out
a way to keep the dbm file open across multiple requests. Ideas??
I seem to remember that that no free dbm implementation supports
concurrent access (which you'd need for prefork mpm). I think the
commercial version by sleepycat does, but who cares about that...
I was thinking we'd still use the current global locking scheme, but
keep the file open between requests. Not sure if this would be robust or
just asking for dbm file corruption though.
Jim
