SQL SERVER – 15 Best Practices for Better Database Performance

This blog post will discuss 15 best practices for improving database performance. I have listed 14 best practices below. Read through them and let me know what you think should be the 15th best practice.

1. Store only relevant and necessary data in the database
   Avoid storing data in application structures or arrays when it belongs in the database.
2. Use normalized tables
   Normalize your database to eliminate redundancy and maintain data integrity. Smaller, related tables are often better than one large table.
3. Create lookup tables for enumerated fields
   For enumerated fields, use lookup tables to enforce consistency and maintain database integrity.
4. Use small and efficient primary keys
   Choose short primary keys, such as integers or small character fields, to optimize performance.
5. Store image paths or URLs instead of images
   Save image paths or URLs in the database and store the images in file storage to reduce overhead.
6. Select appropriate data types
   Use precise data types for fields, such as DATETIME for date fields instead of VARCHAR(20).
7. **Avoid SELECT ***
   Specify column names in SELECT statements to improve performance and readability.
8. Use LIKE clauses sparingly
   When an exact match is required, use the = operator instead of LIKE for better efficiency.
9. Write SQL keywords in uppercase
   Using uppercase for keywords such as SELECT, WHERE, and JOIN enhances code readability.
10. Prefer JOINs over subqueries
    Use JOIN instead of subqueries or nested queries for improved performance and clarity.
11. Utilize stored procedures
    Stored procedures improve execution speed, simplify maintenance, and enhance security.
12. Comment and document your code
    Add comments to your SQL scripts for clarity and as a guide for future developers. Proper application documentation is equally important.
13. Use proper indexing
    Create and maintain indexes to improve query performance, keeping in mind the trade-off with write operations.
14. Test all changes thoroughly
    Test any database programming or administrative changes in a non-production environment before deployment.
15. Monitor and optimize query performance
    Use tools like SQL Server Profiler or Query Store to identify and optimize slow-performing queries. Regularly review execution plans to ensure efficient operations.

These practices will help you design, maintain, and optimize databases and for database performance and long-term reliability. Let me know your thoughts or if you have additional tips to share!

Reference: Pinal Dave (https://blog.sqlauthority.com)