[Opensource] SEC: UNCLASSIFIED - Urgent Help! Horrendous Expresso DBObject per formance problem.

[Michael Rimov]

At 10:11 AM 4/3/2003 +1000, you wrote:
>We setup a test class that hit expresso for a single field (of the same
>record), based on the primary key 10000 times, and got an average response
>of 4ms (startup costs were removed from the timings, and expresso was
>'warmed up' with 2000 hits'.   This results in a total time of 16s for our
>response, which is well above our 1s expectation.  We have caching enabled
>('y' in the config file) and we have an entry in the DBObjLimit table that
>gives ample room for entries, but this doesn't seem to improve the
>performance enough (we got an initial 1/3 performance improvement through
>this).
>
>Is this an expected time (4ms for a cached retrieval), and has anyone else
>had any experiences in this area/know of a solution?


There's a chance that it could be true since Cache retrieval requires a 
DBObject clone [for object integrity sake]. If the objects are completely 
readonly, I would recommend storing a single reference in something like a 
LRUHashMap, and retrieve the references from there.

Otherwise, I would honestly recommend sitting down with a profiler, and see 
where your CPU time is going.  Might be something simple causing the time 
delay that can be easily fixed.  You've got a great test case to throw at 
the profiler.

                                                 -Mike