PostgreSQL Index Optimization: Speed Up Your Queries

Database performance is one of the dominant factors in application speed. In this post we examine PostgreSQL indexing strategies with real examples.

Using EXPLAIN ANALYZE

Before optimizing a query, you must know where it's slow. EXPLAIN ANALYZE provides the real execution plan and timings.

Composite Index Order Matters

For WHERE a = 1 AND b = 2, an index on (a, b) can be used for both WHERE a=1 and WHERE a=1 AND b=2. But (b, a) is only useful for WHERE b=2, not WHERE a=1.

Partial Indexes

If you only query active=true rows, a partial index (WHERE active=true) is far more efficient than a full-table index.