インデックスを表示 [FROM|IN]
文SHOW INDEXES [FROM|IN] 、指定されたテーブルのインデックスを一覧表示します。文SHOW INDEX [FROM|IN]とSHOW KEYS [FROM|IN]この文のエイリアスであり、MySQLとの互換性のために用意されています。
概要
- ShowIndexStmt
- ShowLikeOrWhere
ShowIndexStmt ::=
"SHOW" ( "INDEX" | "INDEXES" | "KEYS" ) ("FROM" | "IN" ) TableName (("FROM" | "IN") SchemaName )? ShowLikeOrWhere?
ShowLikeOrWhere ::=
"LIKE" SimpleExpr
| "WHERE" Expression
例
mysql> CREATE TABLE t1 (id int not null primary key AUTO_INCREMENT, col1 INT, INDEX(col1));
Query OK, 0 rows affected (0.12 sec)
mysql> SHOW INDEXES FROM t1;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| t1 | 0 | PRIMARY | 1 | id | A | 0 | NULL | NULL | | BTREE | | | YES | NULL |
| t1 | 1 | col1 | 1 | col1 | A | 0 | NULL | NULL | YES | BTREE | | | YES | NULL |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
2 rows in set (0.00 sec)
mysql> SHOW INDEX FROM t1;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| t1 | 0 | PRIMARY | 1 | id | A | 0 | NULL | NULL | | BTREE | | | YES | NULL |
| t1 | 1 | col1 | 1 | col1 | A | 0 | NULL | NULL | YES | BTREE | | | YES | NULL |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
2 rows in set (0.00 sec)
mysql> SHOW KEYS FROM t1;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| t1 | 0 | PRIMARY | 1 | id | A | 0 | NULL | NULL | | BTREE | | | YES | NULL |
| t1 | 1 | col1 | 1 | col1 | A | 0 | NULL | NULL | YES | BTREE | | | YES | NULL |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
2 rows in set (0.00 sec)
TiDB BTREE HASHのインデックス タイプをRTREEますが、無視されることに注意してください。
MySQLの互換性
TiDBのSHOW INDEXES [FROM|IN]文はMySQLと完全に互換性があります。互換性に違いがある場合は、 バグを報告する参照してください。