We are running a SQR program on Unix Platform with Oracle RDBMS.
It's an interfacing program to integrate data from foreign sites to
PeopleSoft database, using a flat file input.
After many hours of processing, the program stops with a coredump error (memory fault). With top command we noticed that the size of the occupied memory by the sqr process grow up to 256M, and the pprogram stops just after with coredump. Other processes can go over 600M of occupied memory.
The same program with the same input file completes execution without problems in Windows NT system (the process swap memory from hard disk).
I am waiting for any idea: how to force swapping to a process in Unix, or an easy way to solve this issue, ....

Thanks for your help.

You don't mention the OS being used - please post it (with version). Some (example Solaris) have parameters set up in /etc/system for database software. Check your Oracle documentation to insure your OS is set up for running Oracle (only mentioned since it is hard to say that the other processes you wrote about were not specifically said to be Oracle processes).