PostgreSQL's JSONB-like indexable column in Tarantool? - tarantool

Question

In PostgreSQL we can create a JSONB column that can be indexed and accessed something like this:
CREATE TABLE foo (
id BIGSERIAL PRIMARY KEY
-- createdAt, updatedAt, deletedAt, createdBy, updatedBy, restoredBy, deletedBy
data JSONB
);
CREATE INDEX ON foo((data->>'email'));
INSERT INTO foo(data) VALUES('{"name":"yay","email":"a#1.com"}');
SELECT data->>'name' FROM foo WHERE id = 1;
SELECT data->>'name' FROM foo WHERE data->>'email' = 'a#1.com';
Which is very beneficial in the prototyping phase (no need for migration at all or locking when adding column).
Can we do similar thing in Tarantool?

Answer 1

Sure, tarantool supports JSON path indices. The example:
-- Initialize / load the database.
tarantool> box.cfg{}
-- Create a space with two columns: id and obj.
-- The obj column supposed to contain dictionaries with nested data.
tarantool> box.schema.create_space('s',
> {format = {[1] = {'id', 'unsigned'}, [2] = {'obj', 'any'}}})
-- Create primary and secondary indices.
-- The secondary indices looks at the nested field obj.timestamp.
tarantool> box.space.s:create_index('pk',
> {parts = {[1] = {field = 1, type = 'unsigned'}}})
tarantool> box.space.s:create_index('sk',
> {parts = {[1] = {field = 2, path = 'timestamp', type = 'number'}}})
-- Insert three tuples: first, third and second.
tarantool> clock = require('clock')
tarantool> box.space.s:insert({1, {text = 'first', timestamp = clock.time()}})
tarantool> box.space.s:insert({3, {text = 'third', timestamp = clock.time()}})
tarantool> box.space.s:insert({2, {text = 'second', timestamp = clock.time()}})
-- Select tuples with timestamp of the last hour, 1000 at max.
-- Sort them by timestamp.
tarantool> box.space.s.index.sk:select(
> clock.time() - 3600, {iterator = box.index.GT, limit = 1000})
---
- - [1, {'timestamp': 1620820764.1213, 'text': 'first'}]
- [3, {'timestamp': 1620820780.4971, 'text': 'third'}]
- [2, {'timestamp': 1620820789.5737, 'text': 'second'}]
...
JSON path indices are available since tarantool 2.1.2.