Advice for SQL Server Administrators

SQL Server administrators play a critical role in maintaining efficient, secure, and reliable database systems. The following recommendations are based on best practices for modern SQL Server environments.

1. Avoid Testing in Production

Testing directly in production can expose real users to unvetted code, risking data corruption, security breaches, and customer dissatisfaction. Instead:

* Use staging environments that closely replicate production.

* Populate staging databases with anonymized production-like data.

* Conduct rigorous performance and functional testing before deployment.

2. Separate Services Across Servers

Consolidating services (e.g., SQL Server Analysis Services, Relational Engine, SSIS) onto a single server can lead to resource contention and hinder scalability. Instead:

* Deploy critical services on dedicated servers to improve fault tolerance and performance.

* Use virtualization or containerization to optimize resource usage.

3. Avoid AUTO_SHRINK

The AUTO_SHRINK setting can cause fragmentation and degrade performance. Proactive disk space management is a better approach:

* Monitor database growth and adjust file sizes manually as needed.

* Regularly rebuild or reorganize indexes to maintain performance.

4. Use Autogrow as a Safety Net

While autogrow is a useful feature, it should not be the primary mechanism for managing file sizes. To avoid performance issues:

* Set appropriate initial file sizes and growth increments.

* Monitor file sizes and preemptively adjust them based on workload.

5. Disable or Secure the SA Account

* Using a single shared SA account is a significant security risk. Instead:

* Disable the SA account if not needed.

* Use individual accounts with role-based access control (RBAC).

* Enforce strong password policies and multi-factor authentication (MFA).

6. Index High-Cardinality Columns

Indexing binary-valued columns (e.g., Boolean flags) is generally ineffective. Instead:

* Focus on indexing high-cardinality columns with diverse values.

* Evaluate query patterns to determine the most beneficial indexes.

7. Allocate Ample Memory

SQL Server benefits significantly from sufficient memory for caching and reducing disk I/O. Limiting memory can degrade performance. Best practices include:

* Allocate memory based on workload and server capacity.

* Monitor memory usage and adjust as necessary.

8. Use ORMs Judiciously

Object-Relational Mappers (ORMs) can simplify development but often generate inefficient SQL. To ensure performance:

* Optimize ORM-generated queries by reviewing execution plans.

* Supplement ORM usage with hand-written SQL for critical operations.

9. Use NOLOCK Sparingly

The NOLOCK hint can lead to dirty reads and inconsistent results. It should not be used indiscriminately. Instead:

* Use NOLOCK only when stale or incomplete data is acceptable.

* Document its use clearly to prevent unintended consequences.

10. Configure MAXDOP Appropriately

The default MAXDOP value may not be optimal for all workloads. To improve performance:

* Set MAXDOP based on server hardware and workload characteristics.

* Follow Microsoft’s guidelines for configuring MAXDOP.

11. Implement Backup and Restore Plans for All Systems

Even BI systems require robust backup and restore plans. To safeguard your data:

* Regularly back up databases, including schema and configurations.

* Test restore procedures periodically to ensure data recoverability.

12. Avoid Row-by-Row Processing

Row-by-row processing (RBAR) is inefficient. SQL Server is optimized for set-based operations. To enhance performance:

* Use set-based queries whenever possible.

* Rewrite RBAR logic into efficient set-based T-SQL statements.

Conclusion

By following these modern best practices, SQL Server administrators can ensure secure, high-performing, and reliable database systems. Avoiding outdated and harmful techniques will result in improved efficiency, scalability, and cost-effectiveness over time.