SHOW VIRTUAL COLUMNS

Introduced or updated: v1.2.832

ENTERPRISE EDITION FEATURE

VIRTUAL COLUMN is an Enterprise Edition feature. Contact Databend Support for a license.

Shows the created virtual columns in the system. Equivalent to SELECT * FROM system.virtual_columns.

Virtual columns are enabled by default starting from v1.2.832.

See also: system.virtual_columns

Preferred Syntax

Use the command in its simplest, most useful form to inspect a specific table or list all virtual columns:

SHOW VIRTUAL COLUMNS [WHERE table = '<table_name>' AND database = '<database_name>']

Example

CREATE TABLE test(id int, val variant);

INSERT INTO
  test
VALUES
  (
    1,
    '{"id":1,"name":"databend"}'
  ),
  (
    2,
    '{"id":2,"name":"databricks"}'
  );

SHOW VIRTUAL COLUMNS WHERE table = 'test' AND database = 'default';
╭───────────────────────────────────────────────────────────────────────────────────────────────────╮
│ database │  table │ source_column │ virtual_column_id │ virtual_column_name │ virtual_column_type │
│  String  │ String │     String    │       UInt32      │        String       │        String       │
├──────────┼────────┼───────────────┼───────────────────┼─────────────────────┼─────────────────────┤
│ default  │ test   │ val           │        3000000000 │ ['id']              │ UInt64              │
│ default  │ test   │ val           │        3000000001 │ ['name']            │ String              │
╰───────────────────────────────────────────────────────────────────────────────────────────────────╯