MySQL5.6幾種建索引方式比較
阿新 • • 發佈：2018-12-31
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.6.17 |
+-----------+
mysql> CREATE TABLE test AS SELECT * FROM information_schema.columns;
mysql> INSERT INTO test SELECT * FROM test;
mysql> INSERT INTO test SELECT * FROM test;
mysql> SELECT COUNT(1) FROM test;
+----------+
| COUNT(1) |
+----------+
| 312928 |
+----------+
1 row in set (0.17 sec)
Query OK, 0 rows affected (1.54 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> ALTER TABLE test DROP INDEX ind_t_column_name;
Query OK, 0 rows affected (0.00 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> CREATE INDEX ind_t_column_name ON test(column_name);
Query OK, 0 rows affected (1.70 sec)
Records: 0 Duplicates: 0 Warnings: 0
ALGORITHM=copy，用於標識改操作是否需要整個表。
mysql> CREATE INDEX ind_t_column_name ON test(column_name) ALGORITHM=copy;
Query OK, 312928 rows affected (5.93 sec)
+-----------+
| version() |
+-----------+
| 5.6.17 |
+-----------+
mysql> CREATE TABLE test AS SELECT * FROM information_schema.columns;
mysql> INSERT INTO test SELECT * FROM test;
mysql> INSERT INTO test SELECT * FROM test;
mysql> SELECT COUNT(1) FROM test;
+----------+
| COUNT(1) |
+----------+
| 312928 |
+----------+
1 row in set (0.17 sec)
ALGORITHM=inplace，就地進行，如果允許的話則修改操作可以直接在該表上執行。
Query OK, 0 rows affected (1.54 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> ALTER TABLE test DROP INDEX ind_t_column_name;
Query OK, 0 rows affected (0.00 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> CREATE INDEX ind_t_column_name ON test(column_name);
Query OK, 0 rows affected (1.70 sec)
Records: 0 Duplicates: 0 Warnings: 0
ALGORITHM=copy，用於標識改操作是否需要整個表。
mysql> CREATE INDEX ind_t_column_name ON test(column_name) ALGORITHM=copy;
Query OK, 312928 rows affected (5.93 sec)
Records: 312928 Duplicates: 0 Warnings: 0
注：
SET old_alter_table=0; --ALGORITHM=inplace
SET old_alter_table=1; --ALGORITHM=copy