system.data_skipping_indices

Contains information about existing data skipping indices in all the tables.

Columns:

  • database (String) — Database name.
  • table (String) — Table name.
  • name (String) — Index name.
  • type (String) — Index type.
  • expr (String) — Expression for the index calculation.
  • granularity (UInt64) — The number of granules in the block.

Example

  1. SELECT * FROM system.data_skipping_indices LIMIT 2 FORMAT Vertical;
  1. Row 1:
  2. ──────
  3. database:    default
  4. table:       user_actions
  5. name:        clicks_idx
  6. type:        minmax
  7. expr:        clicks
  8. granularity: 1
  10. Row 2:
  11. ──────
  12. database:    default
  13. table:       users
  14. name:        contacts_null_idx
  15. type:        minmax
  16. expr:        assumeNotNull(contacts_null)
  17. granularity: 1