tarantool> x.index
---
- 0: &0
    unique: true
    parts:
    - type: unsigned
      is_nullable: false
      fieldno: 1
    id: 0
    space_id: 512
    type: TREE
    name: primary
  1: &1
    unique: false
    parts:
    - type: unsigned
      is_nullable: false
      path: '[*][1]'
      fieldno: 2
    space_id: 512
    id: 1
    type: TREE
    name: secondary
  primary: *0
  secondary: *1
...

tarantool> x.index.secondary:select()
---
- []
...

tarantool> x:put({1, {{1, 2}, {3, 4}}})
---
- [1, [[1, 2], [3, 4]]]
...

tarantool> x.index.secondary:select()
---
- - [1, [[1, 2], [3, 4]]]
  - [1, [[1, 2], [3, 4]]]
...

tarantool> x.index.secondary:count()
---
- 2
...

tarantool> x.index.primary:count()
---
- 1
...