I have extensive experience with various database management systems. For instance, I have managed large-scale Oracle databases for over five years, ensuring high availability and performance. My role involved regular maintenance, including backup and recovery, performance tuning, and user management. Additionally, I have hands-on experience with MySQL and PostgreSQL, where I optimized queries and managed data migrations.

Ensuring data security is paramount. I implement robust access control mechanisms, using roles and permissions to restrict data access to authorized personnel only. Regular audits and monitoring are conducted to detect any unauthorized access attempts. I also ensure that all data is encrypted both at rest and in transit, and I stay updated with the latest security patches and best practices to safeguard against vulnerabilities.

One challenging issue was a sudden performance drop in an e-commerce database during peak hours. Through analysis, I identified that the issue was due to inefficient indexing and excessive locking. I resolved this by redesigning the indexing strategy and optimizing the database configuration to reduce lock contention. This significantly improved the database performance and ensured smooth operations during peak traffic times.

I approach database backup and recovery with a comprehensive strategy. Regular full backups are scheduled, complemented by incremental backups for recent changes. I ensure that backups are stored in secure, off-site locations to prevent data loss due to unforeseen events. For recovery, I have tested procedures in place to restore data quickly and efficiently, minimizing downtime and data loss in case of failures.

I employ several strategies to optimize database performance. These include regular indexing, which improves query response times, and partitioning large tables to manage data more efficiently. I also monitor and analyze query performance, identifying and optimizing slow queries. Additionally, I fine-tune database configurations and allocate appropriate resources based on workload demands to ensure optimal performance.