I make a simple midas appliaciton.
The middle application has three doa control(orlcesession,oracledataset,provider ).
client application has a clientdataset control,when two user open the clinetdataset at the same time,the middletier application hint 'invalid address operate',like multi thread error.
so i put delphi control (database,table,provider) in the middletier application,there is no error happen when client get data.
so i think the doa control not fit mluti cpu machine.