Final answer:
To grant read-only access in Oracle, use the GRANT SELECT command on the required tables or schemas for the designated user, using an account with administrative privileges.
Step-by-step explanation:
To grant read-only access to a user in Oracle, you can use SQL commands to modify the user's privileges. Begin by connecting to the Oracle database using an account with administrative privileges. Next, execute the GRANT SELECT command on the desired tables or schemas to the user. An example command would be GRANT SELECT ON schema.table TO username;. To apply the privilege to multiple tables, repeat this command for each table, or use a wildcard if you want to give access to all tables within a schema. It's essential to review user privileges regularly and adhere to the principle of least privilege, granting users only the access needed for their role.