Learn SQL with Real Code Examples
Updated Nov 27, 2025
Performance Notes
Use indexes to speed up queries
Avoid SELECT * in large tables
Analyze query execution plans
Partition large tables if necessary
Optimize joins and subqueries
Security Notes
Use parameterized queries to prevent SQL injection
Restrict database user privileges
Encrypt sensitive data at rest and in transit
Enable audit logging for access tracking
Regularly update and patch the RDBMS
Monitoring Analytics
Monitor query performance via EXPLAIN and profiling tools
Track slow queries
Audit access and modification of data
Use replication and backup monitoring
Integrate with monitoring dashboards and alerts
Code Quality
Follow naming conventions for tables and columns
Use constraints and foreign keys for integrity
Write modular and reusable queries/stored procedures
Test queries on sample data before production
Document schema and business logic