Bug fix for Oracle: ORA-12519,TNS:no appropriate service handler found.

I often come across such an exception when a long or fast transactions are going on n in Oracle.
Error is:
ORA-12519,TNS:no appropriate service handler found.

I dont know if I can call it as a bug.
The solution for this exception, I found is-
execute following sql statement in sql command window and you will probably out of this bug, but I am not sure if it would be.

Statement:
ALTER SYSTEM SET PROCESSES=150 SCOPE=SPFILE;

Any comments or updates in this post will really be appreciated.