MySQL Best Practices for Optimal Performance and Reliability

MySQL is one of the most widely used relational database management systems in the world. Whether you’re a developer, DBA, or DevOps engineer, following best practices can significantly improve the performance, reliability, and maintainability of your MySQL databases.

Use Appropriate Data Types

Choosing the right data type is critical for performance and storage efficiency.

• Use INT instead of BIGINT unless you truly need a huge range.
• Avoid TEXT and BLOB unless necessary; prefer VARCHAR with appropriate lengths.
• Use DATETIME or TIMESTAMP for date/time fields depending on your use case.
• Normalize booleans to TINYINT(1) (0 or 1).

Index Wisely

Indexes speed up read queries but slow down writes and take up space.

• Index columns used in WHERE, JOIN, ORDER BY, and GROUP BY.
• Use composite indexes for multi-column queries.
• Avoid indexing every column—too many indexes can backfire.
• Periodically review and drop unused indexes.

Normalize (but not too much)

Normalization avoids redundancy, but over-normalization can lead to complex joins and degraded performance.

• Aim for third normal form (3NF).
• Use denormalization for read-heavy applications where performance trumps strict normalization.

Use Prepared Statements

Prepared statements prevent SQL injection and improve performance for repeated queries. They also allow MySQL to reuse execution plans, speeding up query processing.

Monitor and Tune Queries

Use the following tools to analyze and improve queries:

• EXPLAIN to check query execution plans.
• SHOW PROCESSLIST to see currently running queries.
• slow_query_log to find performance bottlenecks.
• Tools like MySQLTuner, Percona Toolkit, or pt-query-digest.

Backups and Disaster Recovery

• Schedule regular backups using mysqldump, mysqlpump, or tools like Percona XtraBackup.
• Test restoring backups periodically.
• Use binary logs for point-in-time recovery.

Configuration and Tuning

Default settings aren’t optimized for production.

• Adjust innodb_buffer_pool_size to 70–80% of available memory.
• Tune query_cache_size, max_connections, tmp_table_size, and sort_buffer_size.
• Use the my.cnf configuration file to apply persistent settings.

Secure Your Database

• Never use the root user for application access.
• Use strong passwords.
• Limit access using GRANT and restrict by host.
• Enable SSL for client-server communication.
• Disable remote root access.

Use Connection Pooling

Connection pooling reduces overhead by reusing database connections.

• Use tools like ProxySQL, HAProxy, or app-level pools (e.g., HikariCP, SQLAlchemy pool).
• Especially useful for high-concurrency web applications.

Regular Maintenance

• Analyze and optimize tables (ANALYZE TABLE, OPTIMIZE TABLE).
• Purge old binary logs.
• Keep MySQL up to date with security patches and performance improvements.