You can execute the SHOW INDEX statement to view local secondary indexes and global secondary indexes of tables in PolarDB-X.

Syntax

SHOW {INDEX | INDEXES | KEYS}
    {FROM | IN} tbl_name
    [{FROM | IN} db_name]
    [WHERE expr]

Examples

SHOW INDEX FROM t_order;
+--------------+------------+-----------+--------------+----------------+-----------+-------------+----------+--------+------+------------+----------+---------------+
| TABLE   | NON_UNIQUE | KEY_NAME  | SEQ_IN_INDEX | COLUMN_NAME    | COLLATION | CARDINALITY | SUB_PART | PACKED | NULL | INDEX_TYPE | COMMENT  | INDEX_COMMENT |
+--------------+------------+-----------+--------------+----------------+-----------+-------------+----------+--------+------+------------+----------+---------------+
| t_order |          0 | PRIMARY   |            1 | id             | A         |           0 |     NULL | NULL   |      | BTREE      |          |               |
| t_order |          1 | l_i_order |            1 | order_id       | A         |           0 |     NULL | NULL   | YES  | BTREE      |          |               |
| t_order |          0 | g_i_buyer |            1 | buyer_id       | NULL      |           0 |     NULL | NULL   | YES  | GLOBAL     | INDEX    |               |
| t_order |          1 | g_i_buyer |            2 | id             | NULL      |           0 |     NULL | NULL   |      | GLOBAL     | COVERING |               |
| t_order |          1 | g_i_buyer |            3 | order_id       | NULL      |           0 |     NULL | NULL   | YES  | GLOBAL     | COVERING |               |
| t_order |          1 | g_i_buyer |            4 | order_snapshot | NULL      |           0 |     NULL | NULL   | YES  | GLOBAL     | COVERING |               |
+--------------+------------+-----------+--------------+----------------+-----------+-------------+----------+--------+------+------------+----------+---------------+
6 rows in set (0.01 sec)
Table 1. Column descriptions
Column Description
TABLE The table name.
NON_UNIQUE Indicates whether the index is a unique global secondary index. Valid values:
  • 1: a common global secondary index
  • 0: a unique global secondary index
KEY_NAME The index name.
SEQ_IN_INDEX The ordinal number of the index key column in the index. The value starts from 1.
COLUMN_NAME The name of the index key column.
COLLATION The sorting order. Valid values:
  • A: ascending order
  • D: descending order
  • NULL: not sorted
CARDINALITY The estimated number of unique values.
SUB_PART The prefix of the index. NULL indicates that the prefix of the index is the entire column name.
PACKED The information about field compression. NULL indicates that compression is not applied.
NULL Indicates whether the column can be empty.
INDEX_TYPE The index type. Valid values:
  • NULL: indicates that the index type is not specified.
  • BTREE
  • HASH
COMMENT The information about the index. Valid values:
  • NULL: local secondary index
  • INDEX: the index key column of the global secondary index
  • COVERING: the covering column of the global secondary index
INDEX_COMMENT Other information about the index.