10+ Senior Database Administrator Interview Questions and Answers

I would analyze the performance issue and take appropriate actions to resolve it.

• Identify the specific performance issue and gather relevant data

• Analyze the database configuration and settings

• Review the migration process and identify any potential issues

• Optimize queries and indexes

• Consider hardware and infrastructure upgrades if necessary

• Implement performance monitoring and tuning

• Collaborate with developers and stakeholders to understand application requirements

• Consider scali...read more

Data dictionary tables store metadata about database objects. History data is stored in audit tables or separate history tables.

• Data dictionary tables contain information about database objects such as tables, columns, indexes, and constraints.

• History data can be stored in audit tables that track changes to data over time.

• Separate history tables can also be used to store historical data.

• Examples of data dictionary tables include SYSOBJECTS and SYSCOLUMNS in Microsoft SQL Serv...read more

To resolve LSN mismatch error after restoring a full backup, you can perform a tail-log backup and restore it.

• Perform a tail-log backup of the database.

• Restore the tail-log backup to bring the database to a consistent state.

• Ensure that the LSNs match between the restored full backup and the tail-log backup.

• If the LSNs still do not match, you may need to restore a more recent full backup and apply subsequent transaction log backups.

• Verify the database integrity after the resto...read more

Standby Redo logfiles are required for data protection and disaster recovery in Oracle databases.

• Standby Redo logfiles are essential for maintaining a standby database in Oracle Data Guard for disaster recovery purposes.

• They contain a record of changes made to the primary database, which can be applied to the standby database to keep it synchronized.

• In case of a primary database failure, the standby database can be activated quickly using the standby redo logfiles to minimize...read more

Hop Amp CPU is a performance issue caused by excessive CPU usage in a database server.

• Hop Amp CPU occurs when a database server is overloaded with too many queries or transactions.

• It can also be caused by poorly optimized queries or inefficient database design.

• Hop Amp CPU can lead to slow response times, system crashes, and other performance issues.

• To prevent Hop Amp CPU, database administrators should monitor server performance, optimize queries, and ensure efficient databas...read more

Data protection techniques are essential for safeguarding sensitive information from unauthorized access or theft.

• Encryption of data at rest and in transit

• Access controls and authentication mechanisms

• Regular backups and disaster recovery plans

• Data masking and anonymization

• Monitoring and auditing of database activity

DBA activities include database design, installation, configuration, backup and recovery, performance tuning, security management, and troubleshooting.

• Database design and implementation

• Installation and configuration of database software

• Backup and recovery of databases

• Performance tuning of databases

• Security management of databases

• Troubleshooting database issues

Disk utilisation monitor tracks disk usage and performance.

• Use monitoring tools like Nagios, Zabbix, or Prometheus to track disk utilisation.

• Monitor disk space usage to ensure it doesn't exceed a certain threshold.

• Monitor disk I/O performance to identify bottlenecks or issues.

• Set up alerts or notifications for critical disk utilisation levels or performance degradation.

• Regularly analyze disk utilisation data to identify trends or patterns.

• Consider implementing disk partitioni...read more

WAL is a method used in database systems to ensure data integrity by writing changes to a log before updating the actual data.

• WAL is a protocol used to guarantee that no data modifications are lost in case of a system crash.

• Changes are first written to a log file before being applied to the actual data files.

• This allows for quick recovery and ensures data consistency.

• Examples of databases that use WAL include PostgreSQL and SQLite.

PostgreSQL follows a client-server model architecture with a multi-process architecture.

• PostgreSQL follows a client-server model architecture

• It has a multi-process architecture with a separate process for each client connection

• The main components include the PostgreSQL server process, shared memory, and background processes

• It supports multiple storage engines and has a flexible plugin architecture

Dataguard is an Oracle feature that provides high availability and disaster recovery for databases.

• Dataguard creates and maintains a standby database that can take over in case of a primary database failure.

• It uses redo apply technology to keep the standby database synchronized with the primary database.

• Dataguard can be configured in various modes such as maximum availability mode, maximum performance mode, and maximum protection mode.

• It also supports automatic failover and s...read more