In case of emergency changes to a database after normal working hours, how should a database administrator (DBA) log in?

Logging in with a named account to make emergency changes to a database reflects best practices in security and accountability. When a DBA uses their individual, named account, it ensures that their actions can be traced directly to them, promoting personal responsibility and auditability. This approach is critical in environments that require strict compliance with auditing standards, as it allows for clear tracking of who made changes to the database.

Using a shared DBA account lacks individual accountability since multiple users may share the same credentials, making it difficult to determine who performed specific actions. Logging in with a server administrative account often provides excessive privileges, which can lead to unintentional changes or security vulnerabilities. Operating under a user's account doesn't align with the necessary privileges typically required for a DBA to perform emergency changes, risking ineffective resolution of the issue at hand.

Therefore, using a named account aligns with the principle of least privilege while maintaining a strong security posture and ensuring traceability in administrative actions.