SQL

SQL Performance Optimization: Practical Tips Fine-tuning SQL performance starts with watching what the database does, not guessing. Before changing code or server settings, measure with a realistic workload and a recent dataset. Small gains from careful indexing and query structure add up quickly. In this guide you’ll find practical steps you can apply today, with ideas that work in MySQL, PostgreSQL, or MariaDB. Start by writing clean queries and selecting only what you need. Avoid SELECT * and return only the columns you display. This reduces I/O and makes it easier for the planner to choose efficient plans. Next, invest in the right indexes. A good index supports common lookups and range queries, and a composite index can cover a whole WHERE and ORDER BY clause, letting the database read from the index instead of the table. Ensure columns used in WHERE predicates are mapped to the index, and avoid applying functions to indexed columns in the predicate, which disables usage. ...