Index JSONB Columns for Efficient Querying

JSONB queries without indexes scan the entire table. Use GIN indexes for containment queries.

Incorrect (no index on JSONB):

create table products (
  id bigint primary key,
  attributes jsonb
);

-- Full table scan for every query
select * from products where attributes @> '{"color": "red"}';
select * from products where attributes->>'brand' = 'Nike';

Correct (GIN index for JSONB):

-- GIN index for containment operators (@>, ?, ?&, ?|)
create index products_attrs_gin on products using gin (attributes);

-- Now containment queries use the index
select * from products where attributes @> '{"color": "red"}';

-- For specific key lookups, use expression index
create index products_brand_idx on products ((attributes->>'brand'));
select * from products where attributes->>'brand' = 'Nike';

Choose the right operator class:

-- jsonb_ops (default): supports all operators, larger index
create index idx1 on products using gin (attributes);

-- jsonb_path_ops: only @> operator, but 2-3x smaller index
create index idx2 on products using gin (attributes jsonb_path_ops);

Reference: JSONB Indexes