PostgreSQL Performance & Query Optimization · Lesson

Querying JSONB with JSONPath

Apply SQL/JSON path expressions to filter and extract nested values with index support.

Why JSONPath for JSONB

PostgreSQL stores semi-structured data in the jsonb type. Pulling nested values with the classic -> and ->> operators works, but gets clumsy fast for deep paths, arrays, and conditional filters.

The SQL/JSON path language (added in PostgreSQL 12) gives you a compact, expressive way to navigate and filter JSON. It powers two key functions:

jsonb_path_query / jsonb_path_query_array — extract matching values
jsonb_path_exists and the @? / @@ operators — test predicates

Best of all, those operators can be accelerated by a GIN index, which is exactly what this lesson is about.

A sample JSONB document

Imagine an orders table with a data jsonb column. A single row might hold a document like the one below.

Throughout this lesson we will navigate into customer, iterate over the items array, and filter by numeric and string conditions.

SELECT '{
  "id": 1042,
  "status": "shipped",
  "customer": { "name": "Mara", "tier": "gold" },
  "items": [
    { "sku": "A-1", "qty": 2, "price": 19.90 },
    { "sku": "B-7", "qty": 1, "price": 4.50 }
  ]
}'::jsonb AS data;

All lessons in this course

← Back to PostgreSQL Performance & Query Optimization