Does JSONB support indexing, and how does it improve performance?

Yes, JSONB supports powerful indexing that dramatically improves query performance. GIN (Generalized Inverted Index) indexes enable fast containment queries, equality checks, and existence tests on JSONB columns. GIN indexes decompose JSONB into keys and values, allowing efficient lookups without scanning entire documents. B-tree indexes work on specific JSONB paths extracted with operators like ->>. Expression indexes enable indexing computed values from JSONB. Indexes reduce query time from seconds to milliseconds for large tables. CREATE INDEX idx ON table USING GIN(jsonb_column) creates a standard GIN index. For specific fields, CREATE INDEX idx ON table((jsonb_column->'field')) indexes that path. Partial indexes combine JSONB conditions with WHERE clauses for targeted optimization. GIN indexes increase storage requirements by 50-100% of JSONB data size. Maintenance overhead increases with write operations. Validate JSONB structure with our JSON Viewer at jsonconsole.com/json-viewer when designing schemas. Properly indexed JSONB approaches relational column performance while maintaining schema flexibility. Indexing transforms JSONB from flexible but slow to flexible and fast.