projections
Contains information about existing projections in all the tables.
Columns:
- database(String) — Database name.
- table(String) — Table name.
- name(String) — Projection name.
- type(Enum) — Projection type ('Normal' = 0, 'Aggregate' = 1).
- sorting_key(Array(String)) — Projection sorting key.
- query(String) — Projection query.
Example
SELECT * FROM system.projections LIMIT 2 FORMAT Vertical;
Row 1:
──────
database:    default
table:       landing
name:        improved_sorting_key
type:        Normal
sorting_key: ['user_id','date']
query:       SELECT * ORDER BY user_id, date
Row 2:
──────
database:    default
table:       landing
name:        agg_no_key
type:        Aggregate
sorting_key: []
query:       SELECT count()