SQL DB Performance Tuning

 

Comprehensive SQL Server Performance Tuning Checklist for Large Databases on SQL Server 2019 (Standard) and Windows Server 2019 (VM)

This detailed checklist provides a structured approach to ensure comprehensive coverage of all critical areas for maintaining optimal performance in a high-demand environment. The checklist focuses on practical, hands-on tasks.

1. General Environment Assessment

• System Specifications:
• Verify VM specifications (CPU cores, memory, storage).
• Ensure that the VM is running on a hypervisor optimized for SQL Server.
• Operating System:
• Check for the latest Windows Server 2019 updates and patches.
• Optimize power plan settings for high performance.
• SQL Server Version:
• Confirm SQL Server 2019 is running the latest cumulative updates.

2. Configuration and Settings

• Memory Configuration:
• Set max server memory to prevent SQL Server from using all available memory.
• Set min server memory to ensure SQL Server has enough memory to avoid constant paging.
• CPU Settings:
• Configure max degree of parallelism (typically set to the number of cores per NUMA node).
• Set cost threshold for parallelism to a higher value (e.g., 50) to reduce the number of parallel plans.
• File Placement:
• Place data files (mdf/ndf), log files (ldf), and TempDB files on separate virtual disks to reduce I/O contention.
• Database Settings:
• Set auto-growth settings for data and log files to fixed sizes rather than percentages.
• Verify database compatibility level to match SQL Server 2019.
• Ensure READ_COMMITTED_SNAPSHOT is enabled to reduce locking.

3. Indexing Strategy

• Index Usage:
• Run sys.dm_db_index_usage_stats to identify unused and redundant indexes.
• Drop or consolidate indexes that are rarely used.
• Fragmentation:
• Use sys.dm_db_index_physical_stats to identify fragmented indexes.
• Rebuild or reorganize fragmented indexes based on their fragmentation percentage (e.g., reorganize for 10-30%, rebuild for >30%).
• Missing Indexes:
• Use the Missing Index DMVs (e.g., sys.dm_db_missing_index_details) to identify potentially useful indexes.
• Prioritize and create missing indexes that have a high impact on query performance.
• Index Maintenance:
• Schedule regular index maintenance jobs (rebuild/reorganize) during off-peak hours.
• Update statistics with full scan regularly.

4. Query Performance

• Slow Queries:
• Use SQL Profiler or Extended Events to capture slow-running queries.
• Analyze the captured queries to identify performance bottlenecks.
• Execution Plans:
• Use Execution Plan Analyzer to identify costly operations like table scans and index scans.
• Optimize execution plans by adding indexes, rewriting queries, or updating statistics.
• Query Optimization:
• Avoid SELECT * in queries; specify only required columns.
• Use parameterized queries to prevent SQL injection and promote plan reuse.
• Avoid using cursors; replace them with set-based operations whenever possible.
• Parameter Sniffing:
• Use OPTIMIZE FOR UNKNOWN or OPTION (RECOMPILE) to handle parameter sniffing issues.

5. TempDB Optimization

• File Configuration:
• Configure multiple TempDB data files (typically 1 per CPU core up to 8) to reduce allocation contention.
• Set initial size and auto-growth settings for TempDB files to the same values.
• File Placement:
• Place TempDB on the fastest available storage to improve performance.
• Monitor Usage:
• Regularly monitor TempDB space usage using DMVs like sys.dm_db_file_space_usage.

6. Monitoring and Diagnostics

• Performance Monitoring:
• Use SQL Server Management Studio (SSMS) Performance Dashboard.
• Utilize Performance Monitor (PerfMon) and SQL Server DMVs for real-time monitoring.
• Baselining:
• Establish performance baselines using tools like SQL Sentry or SolarWinds Database Performance Analyzer.
• Alerts:
• Set up SQL Server Agent alerts for critical thresholds (e.g., CPU usage > 80%, disk I/O latency).

7. Deadlock and Blocking Investigation

• Deadlock Monitoring:
• Enable and capture deadlock graphs using Extended Events or SQL Profiler.
• Blocking Analysis:
• Use DMVs like sys.dm_exec_requests and sys.dm_tran_locks to identify and resolve blocking issues.
• Isolation Levels:
• Use appropriate transaction isolation levels to balance concurrency and consistency (e.g., READ_COMMITTED_SNAPSHOT).

8. Backup and Maintenance Practices

• Backup Strategy:
• Implement a robust backup strategy including full, differential, and transaction log backups.
• Verify backups by restoring them to a test environment regularly.
• DBCC CHECKDB:
• Schedule DBCC CHECKDB to run regularly to ensure database integrity.
• Maintenance Plans:
• Use SQL Server Maintenance Plans or custom jobs to automate routine maintenance tasks.

9. Review of Applications and Connections

• Connection Pooling:
• Optimize connection pooling settings in application configurations.
• App Configuration:
• Ensure applications are using efficient query patterns and avoiding excessive database round trips.
• Connection Strings:
• Review and optimize connection strings for performance and security.

10. Network Performance

• Bandwidth:
• Ensure the network bandwidth is sufficient for database operations, especially for large data transfers.
• Latency:
• Monitor and address network latency issues using tools like Wireshark.
• Network Configuration:
• Optimize TCP/IP settings for SQL Server communication.

11. SQL Server Configuration

• Optimize for Ad Hoc Workloads:
• Enable this option to reduce memory footprint of single-use query plans.
• sp_configure 'optimize for ad hoc workloads', 1; RECONFIGURE;
• Max Worker Threads:
• Ensure max worker threads is set appropriately for your workload.
• Default is typically sufficient, but adjust if necessary based on concurrency requirements.

12. Disk I/O Optimization

• Storage Configuration:
• Use high-performance SSDs or NVMe drives for data and log files.
• Ensure storage latency is below 10ms for optimal performance.
• Disk Alignment:
• Check and ensure that disk partitions are aligned with storage blocks.
• RAID Configuration:
• Use RAID 10 for data files to balance performance and redundancy.
• Use RAID 1 or RAID 10 for log files to ensure write performance.

13. High Availability and Disaster Recovery (HADR)

• Always On Availability Groups:
• Configure Availability Groups for high availability and disaster recovery.
• Ensure synchronous replication for critical databases.
• Failover Cluster Instances:
• Use SQL Server Failover Cluster Instances for high availability at the server level.
• Log Shipping:
• Implement log shipping for secondary databases that do not require real-time synchronization.
• Backups:
• Regularly test backup and restore processes to ensure data integrity and recovery readiness.

14. SQL Server Resource Governor

• Resource Pools:
• Create resource pools to allocate CPU and memory resources effectively.
• Use Resource Governor to manage and prioritize workloads.
• Workload Groups:
• Define workload groups to control resource usage by different types of queries or applications.

15. Database Design and Normalization

• Schema Design:
• Ensure your database schema is normalized to reduce redundancy and improve data integrity.
• Use appropriate normalization techniques up to 3NF or higher as required.
• Partitioning:
• Implement table and index partitioning to manage large tables more efficiently.
• Use partitioning to improve query performance and manageability.

16. Security and Compliance

• Encryption:
• Use Transparent Data Encryption (TDE) to encrypt data at rest.
• Implement column-level encryption for sensitive data.
• Access Control:
• Implement role-based access control (RBAC) to manage permissions.
• Use Windows Authentication wherever possible for better security management.
• Auditing:
• Enable SQL Server Audit to track and log security-related events.

17. Application and Query Tuning

• Parameterization:
• Use parameterized queries to enhance plan reuse and reduce SQL injection risks.
• Query Store:
• Enable Query Store to monitor and analyze query performance over time.
• Use Query Store to identify and force optimal execution plans.
• Query Hints:
• Use query hints sparingly to influence execution plans only when necessary.

18. Monitoring Tools and Third-Party Solutions

• Monitoring Tools:
• Use built-in tools like SQL Server Management Studio (SSMS) Performance Dashboard.
• Consider third-party monitoring tools like SolarWinds DPA, Redgate SQL Monitor, or SentryOne.
• Baselining and Alerts:
• Establish performance baselines to understand normal behavior.
• Set up alerts for anomalies and performance thresholds.

19. Application Architecture Review

• Connection Management:
• Ensure efficient management of database connections in the application.
• Use connection pooling to reduce overhead associated with opening and closing connections.
• Data Access Patterns:
• Optimize data access patterns to minimize database round trips.
• Use appropriate data retrieval techniques (e.g., batch processing).

20. Documentation and Knowledge Sharing

• Documentation:
• Maintain comprehensive documentation for all database configurations, performance tuning actions, and best practices.
• Training and Knowledge Sharing:
• Provide regular training sessions for the development and DBA teams on SQL Server best practices.
• Encourage knowledge sharing and collaboration within the team to address performance issues efficiently.

21. Linked Servers

• Optimize Linked Server Queries:
• Use OPENQUERY for querying linked servers to improve performance.
• Minimize data transfer between servers by filtering data as much as possible before transferring.
• Linked Server Security:
• Ensure proper security configurations for linked servers to prevent unauthorized access.
• Use the least privilege principle for linked server connections.

22. Integration with ERP Systems

• Data Synchronization:
• Schedule data synchronization tasks during off-peak hours to reduce load on the database.
• Use ETL (Extract, Transform, Load) processes to ensure data consistency between systems.
• ERP Performance Tuning:
• Work with ERP vendors to optimize queries and operations specific to the ERP system.
• Regularly update ERP software to benefit from performance improvements and bug fixes.

23. E-commerce Website Integration

• Connection Pooling:
• Implement connection pooling to handle high volumes of connections efficiently.
• Caching:
• Use caching mechanisms (e.g., Redis, Memcached) to reduce database load for frequently accessed data.
• Implement query result caching where applicable to reduce repetitive database hits.
• CDN (Content Delivery Network):
• Use a CDN to offload static content and reduce the load on the database.

24. Log Tables and Transactional Logs

• Log Management:
• Regularly archive and purge old log data to keep log tables manageable.
• Implement partitioning for log tables to improve performance.
• Transactional Log Optimization:
• Ensure the transaction log is on a fast disk subsystem.
• Regularly back up transaction logs to prevent them from growing excessively.

25. Maintenance and Monitoring

• Index Maintenance:
• Implement regular index maintenance tasks such as rebuilding or reorganizing indexes.
• Statistics Update:
• Regularly update statistics to ensure the query optimizer has current information.
• Database Consistency Checks:
• Schedule regular DBCC CHECKDB operations to ensure database integrity.

26. Performance Monitoring and Diagnostics

• Extended Events and Profiler:
• Use Extended Events for lightweight performance monitoring and troubleshooting.
• Utilize SQL Profiler for detailed query performance analysis during development and testing.
• Dynamic Management Views (DMVs):
• Regularly query DMVs to monitor performance metrics and identify potential bottlenecks.
• Third-Party Monitoring Solutions:
• Consider using third-party tools for advanced monitoring, alerting, and diagnostics.

27. Resource Deadlocks and Blocking

• Deadlock Detection:
• Enable deadlock detection and logging.
• Analyze deadlock graphs to identify and resolve deadlock issues.
• Minimize Blocking:
• Optimize long-running queries to reduce blocking.
• Use appropriate transaction isolation levels to balance performance and consistency.

28. Network Performance

• Network Configuration:
• Ensure the network infrastructure is optimized for low latency and high throughput.
• Use dedicated network interfaces for database traffic where possible.
• Network Encryption:
• Implement SSL/TLS for database connections to secure data in transit.
• Ensure minimal performance overhead by balancing security requirements with performance needs.

29. Review of Applications and Connections

• Application Performance:
• Conduct code reviews and performance testing for applications accessing the database.
• Optimize application code to reduce unnecessary database interactions.
• Connection Management:
• Ensure applications use efficient connection management practices, including proper use of connection pooling.

30. Backup and Maintenance Practices

• Backup Strategies:
• Implement differential and transaction log backups to complement full backups.
• Store backups on separate, reliable storage to ensure availability in case of primary storage failure.
• Maintenance Plans:
• Create and schedule comprehensive maintenance plans covering backups, index maintenance, and integrity checks.
• Testing Backup and Restore:
• Regularly test backup and restore procedures to ensure data can be recovered quickly and accurately.