SHOW INDEX
The SHOW INDEX
statement returns index information for a table.
Required privileges
The user must have any privilege on the target table.
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. |
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: 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 or not the STORING clause was used to index the column during index creation. Possible values: true or false . |
implicit | Whether or not the column is part of the index despite not being explicitly included during index creation. Possible values: true or false At 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
> CREATE TABLE t1 (
a INT PRIMARY KEY,
b DECIMAL,
c TIMESTAMP,
d STRING
);
> CREATE INDEX b_c_idx ON t1 (b, c) STORING (d);
> SHOW INDEX FROM t1;
+------------+------------+------------+--------------+-------------+-----------+---------+----------+
| table_name | index_name | non_unique | seq_in_index | column_name | direction | storing | implicit |
+------------+------------+------------+--------------+-------------+-----------+---------+----------+
| t1 | primary | false | 1 | a | ASC | false | false |
| t1 | b_c_idx | true | 1 | b | ASC | false | false |
| t1 | b_c_idx | true | 2 | c | ASC | false | false |
| t1 | b_c_idx | true | 3 | d | N/A | true | false |
| t1 | b_c_idx | true | 4 | a | ASC | false | true |
+------------+------------+------------+--------------+-------------+-----------+---------+----------+
(5 rows)
See also
当前内容版权归 cockroachlabs.com 或其关联方所有,如需对内容或内容相关联开源项目进行关注与资助,请访问 cockroachlabs.com .