Query Index Types

## Choose the Right Index Type for Your Data Different index types excel at different query patterns. The default B-tree isn't always optimal. **Incorrect (B-tree for JSONB containment):** ```sql -- B-tree cannot optimize containment operators create index products_attrs_idx on products (attributes); select * from products where attributes @> '{"color": "red"}'; -- Full table scan - B-tree doesn't support @> operator ``` **Correct (GIN for JSONB):** ```sql -- GIN supports @>, ?, ?&, ?| operators create index products_attrs_idx on products using gin (attributes); select * from products where attributes @> '{"color": "red"}'; ``` Index type guide: ```sql -- B-tree (default): =, , BETWEEN, IN, IS NULL create index users_created_idx on users (created_at); -- GIN: arrays, JSONB, full-text search create index posts_tags_idx on posts using gin (tags); -- BRIN: large time-series tables (10-100x smaller) create index events_time_idx on events using brin (created_at); -- Hash: equality-only (slightly faster than B-tree for =) create index sessions_token_idx on sessions using hash (token); ``` Reference: [Index Types](https://www.postgresql.org/docs/current/indexes-types.html)