The default location is the system tablespace. This is bad because if the system tablespace gets full, the database fails. Create a new tablespace, and have a different user own any tables you create. You can alter the user to use the new tablespace as a default.
create tablespace data datafile ‘/directory/datafile.dbf’ size 100M autoextend on next 100M maxsize unlimited online permanent extent management local autoallocate segment space managment auto;
create user object_owner identified by object_owner_pwd;
alter user object_owner default tablespace data;
grant connect, resource to object_owner; — old school, but still works
— Good answer. I suggest setting a maxsize to something other than unlimited. Like 1000m or 2000m, etc.