Database Administrator interview questions

Best practices include using least privilege access controls, implementing robust authentication mechanisms, regularly auditing database activities, segregating duties among users, encrypting data both at rest and in transit, and continuously applying security patches and updates.

Techniques involve analyzing slow queries through execution plans, indexing optimization, partitioning large tables, tuning database configuration parameters, monitoring resource utilization, and leveraging tools for real-time performance monitoring and diagnostics.

Strategies include enforcing foreign key and unique constraints, using transactions with appropriate isolation levels, implementing triggers for validation, periodic consistency checks, and maintaining thorough backup and restore procedures.

A database administrator defines roles based on job functions, assigns only necessary permissions to each role, conducts regular reviews of role assignments, and removes unneeded privileges to minimize risk, ensuring compliance with security policies.

Monitoring practices include setting up alerting thresholds for critical metrics, tracking slow queries, regularly reviewing resource consumption, and employing automated performance baseline tracking to quickly detect anomalies.

Advanced methods encompass transparent data encryption (TDE), column-level and application-level encryption, use of hardware security modules (HSMs) for key management, and integrating with external key management services for enhanced security.

Tools and processes include implementing checksums, leveraging database-integrated consistency checks, scheduling regular backups with verification routines, deploying data replication across multiple nodes, and using monitoring solutions that alert on anomalies.

Indexing strategies are refined by analyzing usage patterns, eliminating redundant indexes, leveraging covering indexes, refreshing index statistics, and using filtered or partial indexes for selective optimization.

Approaches include disabling unused features and ports, enforcing strong authentication, applying configuration baselines, encrypting communications, regularly auditing configuration changes, and restricting access to sensitive database files.

Policies and procedures involve performing pre- and post-migration integrity checks, validating data transformations, running reconciliation reports, thorough testing in pre-production environments, and maintaining rollback plans to ensure data consistency.