system.data_skipping_indices

Description

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.
type_full (String) — Index type expression from create statement.
expr (String) — Expression for the index calculation.
creation (Enum8(‘Explicit’ = 0, ‘Implicit’ = 1)) — Whether the index was created implicitly (via add_minmax_index_for_numeric_columns or similar)
granularity (UInt64) — The number of granules in the block.
data_compressed_bytes (UInt64) — The size of compressed data, in bytes.
data_uncompressed_bytes (UInt64) — The size of decompressed data, in bytes.
marks_bytes (UInt64) — The size of marks, in bytes.

Example

SELECT * FROM system.data_skipping_indices LIMIT 2 FORMAT Vertical;

Row 1:
──────
database:                default
table:                   user_actions
name:                    clicks_idx
type:                    minmax
type_full:               minmax
expr:                    clicks
creation:                Explicit
granularity:             1
data_compressed_bytes:   58
data_uncompressed_bytes: 6
marks_bytes:             48

Row 2:
──────
database:                default
table:                   users
name:                    contacts_null_idx
type:                    minmax
type_full:               minmax
expr:                    assumeNotNull(contacts_null)
creation:                Explicit
granularity:             1
data_compressed_bytes:   58
data_uncompressed_bytes: 6
marks_bytes:             48