Indexing JSONB in Postgres

PostgreSQL's JSONB datatype offers powerful querying capabilities, but requires proper indexing for optimal performance. GIN (Generalized Inverted Index) indexes are ideal for containment queries, key existence checks, and JSONB operators like @>, ?, ?|, and ?&. However, GIN indexes don't help with path-based navigation, comparisons, or pattern matching within JSONB values. For these cases, expression indexes using B-tree structures work better. GIN indexes have higher write overhead and can suffer from bloat, requiring periodic maintenance with REINDEX CONCURRENTLY. Best practices include using GIN for containment-style lookups, expression indexes for specific key queries, and combining both approaches for comprehensive JSONB performance optimization.