TNS-12500 intermittent errors

[Jo King]

Environment NT4 4Gb RAM Page Filesize 4.5Gb Oracle Version 8.0.5.1.1   We have recently been experiencing intermittent TNS-12500 Listener unable to create a dedicated server process messages. It does occur when we have around 300 + processes, but even then it appears hit and miss. It has all the hallmarks of being a resource problem, but none of the measurements at time of error(s) seem to bear this out. Once the processes count is reduced ever so slightly, the problem goes away !   Peak memory usage : - Just over 2Gb Oracle Process memory usage max - approx 1.7 Gb Max Oracle Processes - 318 Initialization Parm - Processes = 500    Before I start tracing the listener, I thought I'd ask this list for any ideas.   regards..../Bob