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()