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