A practical field guide to Couchbase indexing. Covers primary vs GSI indexes, composite key ordering, index-order sorting, covering and partial indexes, array indexes (including replacing OR and LIKE), IntersectScan and UnionScan avoidance, replication and partitioning, projection selectivity, the ADVISE and INFER tools, scan consistency, and pagination, all with runnable SQL++ (N1QL) examples against the travel-sample dataset.