SHOW INDEX

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The SHOW INDEX statement returns index information for a table or database.

Required privileges

The user must have any privilege on the target table or database.

Aliases

In CockroachDB, the following are aliases for SHOW INDEX:

  • SHOW INDEXES
  • SHOW KEYS

Synopsis

SHOW INDEX INDEXES KEYS FROM table_name DATABASE database_name WITH COMMENT

Parameters

Parameter Description
table_name The name of the table for which to show indexes.
database_name The name of the database for which to show indexes.

Response

The following fields are returned for each column in each index.

Field Description
table_name The name of the table.
index_name The name of the index.
non_unique Whether values in the indexed column are unique. Possible values: true or false.
seq_in_index The position of the column in the index, starting with 1.
column_name The indexed column.
direction How the column is sorted in the index. Possible values: ASC or DESC for indexed columns; N/A for stored columns.
storing Whether the STORING clause was used to index the column during index creation. Possible values: true or false.
implicit Whether the column is part of the index despite not being explicitly included during index creation. Possible values: true or false

Primary key columns are the only columns implicitly included in secondary indexes. The inclusion of primary key columns improves performance when retrieving columns not in the index.

A column is in the primary key if the value of the index_name column is primary and value of the storing column is false.

Example

Setup

The following examples use MovR, a fictional vehicle-sharing application, to demonstrate CockroachDB SQL statements. For more information about the MovR example application and dataset, see MovR: A Global Vehicle-sharing App.

To follow along, run cockroach demo to start a temporary, in-memory cluster with the movr dataset preloaded:

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$ cockroach demo

Show indexes for a table

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> CREATE INDEX ON users (name);
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> SHOW INDEX FROM users;
  table_name |   index_name   | non_unique | seq_in_index | column_name | direction | storing | implicit
-------------+----------------+------------+--------------+-------------+-----------+---------+-----------
  users      | primary        |   false    |            1 | city        | ASC       |  false  |  false
  users      | primary        |   false    |            2 | id          | ASC       |  false  |  false
  users      | primary        |   false    |            3 | name        | N/A       |  true   |  false
  users      | primary        |   false    |            4 | address     | N/A       |  true   |  false
  users      | primary        |   false    |            5 | credit_card | N/A       |  true   |  false
  users      | users_name_idx |    true    |            1 | name        | ASC       |  false  |  false
  users      | users_name_idx |    true    |            2 | city        | ASC       |  false  |   true
  users      | users_name_idx |    true    |            3 | id          | ASC       |  false  |   true
(8 rows)

In this example, the columns where the value of the index_name column is primary and value of the storing column is false, and thus are in the primary key, are city and id.

Show indexes for a database

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> SHOW INDEXES FROM DATABASE movr;
          table_name         |                  index_name                   | non_unique | seq_in_index |   column_name    | direction | storing | implicit
-----------------------------+-----------------------------------------------+------------+--------------+------------------+-----------+---------+-----------
  users                      | primary                                       |   false    |            1 | city             | ASC       |  false  |  false
  users                      | primary                                       |   false    |            2 | id               | ASC       |  false  |  false
  users                      | primary                                       |   false    |            3 | name             | N/A       |  true   |  false
  users                      | primary                                       |   false    |            4 | address          | N/A       |  true   |  false
  users                      | primary                                       |   false    |            5 | credit_card      | N/A       |  true   |  false
  users                      | users_name_idx                                |    true    |            1 | name             | ASC       |  false  |  false
  users                      | users_name_idx                                |    true    |            2 | city             | ASC       |  false  |   true
  users                      | users_name_idx                                |    true    |            3 | id               | ASC       |  false  |   true
  vehicles                   | primary                                       |   false    |            1 | city             | ASC       |  false  |  false
  vehicles                   | primary                                       |   false    |            2 | id               | ASC       |  false  |  false
  vehicles                   | primary                                       |   false    |            3 | type             | N/A       |  true   |  false
  vehicles                   | primary                                       |   false    |            4 | owner_id         | N/A       |  true   |  false
  vehicles                   | primary                                       |   false    |            5 | creation_time    | N/A       |  true   |  false
  vehicles                   | primary                                       |   false    |            6 | status           | N/A       |  true   |  false
  vehicles                   | primary                                       |   false    |            7 | current_location | N/A       |  true   |  false
  vehicles                   | primary                                       |   false    |            8 | ext              | N/A       |  true   |  false
  vehicles                   | vehicles_auto_index_fk_city_ref_users         |    true    |            1 | city             | ASC       |  false  |  false
  vehicles                   | vehicles_auto_index_fk_city_ref_users         |    true    |            2 | owner_id         | ASC       |  false  |  false
  vehicles                   | vehicles_auto_index_fk_city_ref_users         |    true    |            3 | id               | ASC       |  false  |   true
  rides                      | primary                                       |   false    |            1 | city             | ASC       |  false  |  false
  rides                      | primary                                       |   false    |            2 | id               | ASC       |  false  |  false
  rides                      | primary                                       |   false    |            3 | vehicle_city     | N/A       |  true   |  false
  rides                      | primary                                       |   false    |            4 | rider_id         | N/A       |  true   |  false
  rides                      | primary                                       |   false    |            5 | vehicle_id       | N/A       |  true   |  false
  rides                      | primary                                       |   false    |            6 | start_address    | N/A       |  true   |  false
  rides                      | primary                                       |   false    |            7 | end_address      | N/A       |  true   |  false
  rides                      | primary                                       |   false    |            8 | start_time       | N/A       |  true   |  false
  rides                      | primary                                       |   false    |            9 | end_time         | N/A       |  true   |  false
  rides                      | primary                                       |   false    |           10 | revenue          | N/A       |  true   |  false
  rides                      | rides_auto_index_fk_city_ref_users            |    true    |            1 | city             | ASC       |  false  |  false
  rides                      | rides_auto_index_fk_city_ref_users            |    true    |            2 | rider_id         | ASC       |  false  |  false
  rides                      | rides_auto_index_fk_city_ref_users            |    true    |            3 | id               | ASC       |  false  |   true
  rides                      | rides_auto_index_fk_vehicle_city_ref_vehicles |    true    |            1 | vehicle_city     | ASC       |  false  |  false
  rides                      | rides_auto_index_fk_vehicle_city_ref_vehicles |    true    |            2 | vehicle_id       | ASC       |  false  |  false
  rides                      | rides_auto_index_fk_vehicle_city_ref_vehicles |    true    |            3 | city             | ASC       |  false  |   true
  rides                      | rides_auto_index_fk_vehicle_city_ref_vehicles |    true    |            4 | id               | ASC       |  false  |   true
  vehicle_location_histories | primary                                       |   false    |            1 | city             | ASC       |  false  |  false
  vehicle_location_histories | primary                                       |   false    |            2 | ride_id          | ASC       |  false  |  false
  vehicle_location_histories | primary                                       |   false    |            3 | timestamp        | ASC       |  false  |  false
  vehicle_location_histories | primary                                       |   false    |            4 | lat              | N/A       |  true   |  false
  vehicle_location_histories | primary                                       |   false    |            5 | long             | N/A       |  true   |  false
  promo_codes                | primary                                       |   false    |            1 | code             | ASC       |  false  |  false
  promo_codes                | primary                                       |   false    |            2 | description      | N/A       |  true   |  false
  promo_codes                | primary                                       |   false    |            3 | creation_time    | N/A       |  true   |  false
  promo_codes                | primary                                       |   false    |            4 | expiration_time  | N/A       |  true   |  false
  promo_codes                | primary                                       |   false    |            5 | rules            | N/A       |  true   |  false
  user_promo_codes           | primary                                       |   false    |            1 | city             | ASC       |  false  |  false
  user_promo_codes           | primary                                       |   false    |            2 | user_id          | ASC       |  false  |  false
  user_promo_codes           | primary                                       |   false    |            3 | code             | ASC       |  false  |  false
  user_promo_codes           | primary                                       |   false    |            4 | timestamp        | N/A       |  true   |  false
  user_promo_codes           | primary                                       |   false    |            5 | usage_count      | N/A       |  true   |  false
(51 rows)

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