29b45dd234
- Adds `skills/postgres-best-practices/`: A new skill containing comprehensive Postgres performance optimization rules and guidelines from Supabase. - The skill includes rules for query performance, connection management, security (RLS), and schema design. - Updates `README.md` to include the new skill in the directory.
1.4 KiB
1.4 KiB
title, impact, impactDescription, tags
| title | impact | impactDescription | tags |
|---|---|---|---|
| Index JSONB Columns for Efficient Querying | MEDIUM | 10-100x faster JSONB queries with proper indexing | jsonb, gin, indexes, json |
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