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
Parameters
| Parameter | Description | 
|---|---|
| table_name | The name of the table for which you want to show indexes. | 
| database_name | The name of the database for which you want 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 or not values in the indexed column are unique. Possible values: trueorfalse. | 
| 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: ASCorDESCfor indexed columns;N/Afor stored columns. | 
| storing | Whether or not the STORINGclause was used to index the column during index creation. Possible values:trueorfalse. | 
| implicit | Whether or not the column is part of the index despite not being explicitly included during index creation. Possible values: trueorfalseAt this time, primary key columns are the only columns that get implicitly included in secondary indexes. The inclusion of primary key columns improves performance when retrieving columns not in the index. | 
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:
$ cockroach demo
Show indexes for a table
> CREATE INDEX ON users (name);
> 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      | 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
(5 rows)
Show indexes for a database
> 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
  vehicles                   | primary                                       |   false    |            1 | city         | ASC       |  false  |  false
  vehicles                   | primary                                       |   false    |            2 | id           | ASC       |  false  |  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                      | 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
  promo_codes                | primary                                       |   false    |            1 | code         | ASC       |  false  |  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
(23 rows)