common misconception among Oracle developers is they can run stored procedures in parallel only from outside the database. For example, many use Java-based code that spawns multiple Java threads and runs each procedure on a separate thread (using the java.sql.CallableStatementobject), or UNIX shell scripts using cron to enable this function. But there's no need to reinvent the wheel this way—you can execute stored procedures in parallel inside an Oracle database using PL/SQL code. This 10-Minute Solution describes how, and it explains which types of tasks are suitable for this technique.
How do I run stored procedures in parallel from inside an Oracle database?
Use one of Oracle's prepackaged APIs, the DBMS_JOB package, to submit multiple jobs to a job queue and then run them in parallel.