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本篇文章給大家分享的是有關(guān)Percona MySQL 5.6 WHERE條件中OR的索引測(cè)試該怎么進(jìn)行,小編覺(jué)得挺實(shí)用的,因此分享給大家學(xué)習(xí),希望大家閱讀完這篇文章后可以有所收獲,話不多說(shuō),跟著小編一起來(lái)看看吧。
在測(cè)試表的兩列上分別創(chuàng)建索引。
mysql> select * from test;
+------+-------+
| id | name |
+------+-------+
| 10 | neo |
| 20 | John |
| 30 | Lucy |
| 40 | Larry |
| 50 | Lilly |
+------+-------+
5 rows in set (0.00 sec)
mysql> show keys from test;
Empty set (0.01 sec)
mysql> create index idx_test_id on test(id);
Query OK, 0 rows affected (0.34 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> create index idx_test_name on test(name);
Query OK, 0 rows affected (0.72 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show keys from test;
+-------+------------+---------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+---------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| test | 1 | idx_test_id | 1 | id | A | 5 | NULL | NULL | YES | BTREE | | |
| test | 1 | idx_test_name | 1 | name | A | 5 | NULL | NULL | YES | BTREE | | |
+-------+------------+---------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
2 rows in set (0.02 sec)
mysql> explain select * from test where id=10;
+----+-------------+-------+------+---------------+-------------+---------+-------+------+-------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------+-------------+---------+-------+------+-------+
| 1 | SIMPLE | test | ref | idx_test_id | idx_test_id | 5 | const | 1 | NULL |
+----+-------------+-------+------+---------------+-------------+---------+-------+------+-------+
1 row in set (0.00 sec)
mysql> explain select * from test where name='Lucy';
+----+-------------+-------+------+---------------+---------------+---------+-------+------+-----------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------+---------------+---------+-------+------+-----------------------+
| 1 | SIMPLE | test | ref | idx_test_name | idx_test_name | 18 | const | 1 | Using index condition |
+----+-------------+-------+------+---------------+---------------+---------+-------+------+-----------------------+
1 row in set (0.00 sec)
mysql> explain select * from test where id=10 or name='Lucy';
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
| 1 | SIMPLE | test | ALL | idx_test_id,idx_test_name | NULL | NULL | NULL | 5 | Using where |
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)
mysql> explain select * from test where id=20 or name='Lucy';
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
| 1 | SIMPLE | test | ALL | idx_test_id,idx_test_name | NULL | NULL | NULL | 5 | Using where |
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)
mysql> explain select * from test where id=50 or name='neo';
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
| 1 | SIMPLE | test | ALL | idx_test_id,idx_test_name | NULL | NULL | NULL | 5 | Using where |
+----+-------------+-------+------+---------------------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)
mysql> drop index idx_test_id;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
mysql> drop index idx_test_id on test;
Query OK, 0 rows affected (0.33 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> drop index idx_test_name on test;
Query OK, 0 rows affected (0.02 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> create index idx_test_id on test(id);
Query OK, 0 rows affected (0.09 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> explain select * from test where id=50 or name='neo';
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| 1 | SIMPLE | test | ALL | idx_test_id | NULL | NULL | NULL | 5 | Using where |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)
mysql> explain select * from test where name='neo';
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| 1 | SIMPLE | test | ALL | NULL | NULL | NULL | NULL | 5 | Using where |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)
mysql> explain select * from test where name='Lucy';
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| 1 | SIMPLE | test | ALL | NULL | NULL | NULL | NULL | 5 | Using where |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)
mysql> drop index idx_test_name on test;
ERROR 1091 (42000): Can't DROP 'idx_test_name'; check that column/key exists
mysql> drop index idx_test_id on test;
Query OK, 0 rows affected (0.09 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> create index idx_test_id_name on test(id,name);
Query OK, 0 rows affected (0.21 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show keys from test;
+-------+------------+------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| test | 1 | idx_test_id_name | 1 | id | A | 5 | NULL | NULL | YES | BTREE | | |
| test | 1 | idx_test_id_name | 2 | name | A | 5 | NULL | NULL | YES | BTREE | | |
+-------+------------+------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
2 rows in set (0.00 sec)
mysql> explain select * from test where name='Lucy';
+----+-------------+-------+-------+---------------+------------------+---------+------+------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+-------+---------------+------------------+---------+------+------+--------------------------+
| 1 | SIMPLE | test | index | NULL | idx_test_id_name | 23 | NULL | 5 | Using where; Using index |
+----+-------------+-------+-------+---------------+------------------+---------+------+------+--------------------------+
1 row in set (0.00 sec)
mysql> explain select * from test where name='neo';
+----+-------------+-------+-------+---------------+------------------+---------+------+------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+-------+---------------+------------------+---------+------+------+--------------------------+
| 1 | SIMPLE | test | index | NULL | idx_test_id_name | 23 | NULL | 5 | Using where; Using index |
+----+-------------+-------+-------+---------------+------------------+---------+------+------+--------------------------+
1 row in set (0.00 sec)
mysql> explain select * from test where id=10;
+----+-------------+-------+------+------------------+------------------+---------+-------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+------------------+------------------+---------+-------+------+-------------+
| 1 | SIMPLE | test | ref | idx_test_id_name | idx_test_id_name | 5 | const | 1 | Using index |
+----+-------------+-------+------+------------------+------------------+---------+-------+------+-------------+
1 row in set (0.00 sec)
mysql> explain select * from test where id=10 or name='Lucy';
+----+-------------+-------+-------+------------------+------------------+---------+------+------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+-------+------------------+------------------+---------+------+------+--------------------------+
| 1 | SIMPLE | test | index | idx_test_id_name | idx_test_id_name | 23 | NULL | 5 | Using where; Using index |
+----+-------------+-------+-------+------------------+------------------+---------+------+------+--------------------------+
1 row in set (0.00 sec)
以上就是Percona MySQL 5.6 WHERE條件中OR的索引測(cè)試該怎么進(jìn)行,小編相信有部分知識(shí)點(diǎn)可能是我們?nèi)粘9ぷ鲿?huì)見(jiàn)到或用到的。希望你能通過(guò)這篇文章學(xué)到更多知識(shí)。更多詳情敬請(qǐng)關(guān)注億速云行業(yè)資訊頻道。
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