Oracle Database

Oracle Database is a powerful, proprietary, heavily-licensed enterprise relational database maintained by Oracle Corporation. It sits around #9 in real-world usage (roughly 10.6%) — dominant in large legacy corporate and government systems (banking, insurance, government records) that were built decades ago and never migrated off it.

Core concepts & example

Oracle uses PL/SQL, its own procedural extension of SQL, which allows stored procedures and complex logic directly in the database:

SELECT employee_id, last_name, salary
FROM employees
WHERE salary > 50000
ORDER BY salary DESC;

-- a simple PL/SQL procedure
CREATE OR REPLACE PROCEDURE give_raise(emp_id IN NUMBER) AS
BEGIN
  UPDATE employees SET salary = salary * 1.05 WHERE employee_id = emp_id;
END;

Getting started

Oracle offers a free Express Edition (XE) for local development, most commonly run via Docker:

# run Oracle XE locally via Docker
docker run -d --name oracle-xe -p 1521:1521 -e ORACLE_PASSWORD=yourpassword \
  gvenzl/oracle-xe:21-slim