Designing the Right PostgreSQL Index Using Query Plans and Statistics

PostgreSQL index design is often misunderstood. Many developers think that creating a good index simply means: “Create an index containing the columns from the WHERE clause.” In reality, efficient index design is far more nuanced. The order of columns inside a composite index matters enormously, and the best choice depends on: Predicate types ( = , >= , BETWEEN , LIKE , etc.) Column selectivity Table size PostgreSQL planner statistics Actual execution plans This article explains the core princip