// TRUNCATE// 默认规范配置// innodb_flush_method = on & innodb_flush_method = O_DIRECT(root@127.1)[eolbimsdb]08:44:4615>truncate table t5;QueryOK,0rowsaffected(0.98sec)// 设置 innodb_adaptive_hash_index = off(root@127.1)[eolbimsdb]08:52:035>truncate table t5;QueryOK,0rowsaffected(0...
例1 新建表 tb_student_course,插入数据并查询,SQL 语句和运行结果如下: mysql>CREATE TABLE `tb_student_course` (-> `id`int(4) NOT NULL AUTO_INCREMENT,-> `name` varchar(25) NOT NULL,->PRIMARY KEY (`id`)->); Query OK,0rows affected (0.04sec) mysql> INSERT INTO tb_student_course(na...
Query OK, 0 rows affected (0.03 sec) // 设置 innodb_flush_method = fsync (root@127.1) [eolbimsdb] 09:03:34 28> truncate table t5; Query OK, 0 rows affected (1.04 sec) // 设置 innodb_adaptive_hash_index = off & innodb_flush_method = fsync (root@127.1) [eolbimsdb] 09:20:24 ...
耗时的过程在que_eval_sql: query: PROCEDURE DROP_TABLE_PROC ---> dict_drop_index_tree; row_drop_single_table_tablespace的耗时被 MySQL 5.7 配置innodb_flush_method=O_DIRECT优化了。 Q2:该优化是否适用于 MySQL 8.0? 设置innodb_flush_method=O_DIRECT的优化操作,同样适用于 MySQL 8.0。 Q3:MySQL 8.0...
In the truncate table, adding the WHERE clause is impossible. The following query removes all records from thetblStudenttable: Truncate table tblStudent Difference 2: Triggers When we run the DELETE command, the SQL Server invokes the DELETE triggers. ...
Query OK, 0 rows affected (0.03 sec) // 设置 innodb_flush_method = fsync (root@127.1) [eolbimsdb] 09:03:34 28> truncate table t5; Query OK, 0 rows affected (1.04 sec) // 设置 innodb_adaptive_hash_index = off & innodb_flush_method = fsync ...
SQL> DELETE T_BIG; 4 rows deleted. Elapsed: 00:00:00.01 SQL>TRUNCATETABLE T_BIG; Table truncated. Elapsed:00:00:03.25 如果表中数据量不大,TRUNCATE比DELETE慢一点是正常的,但是二者的执行时间一般是同一个数量级的: SQL> CREATE TABLE T_TRUNCATE (ID NUMBER); ...
新建表 tb_student_course,插入数据并查询,SQL 语句和运行结果如下: mysql> CREATE TABLE `tb_student_course` ( -> `id` int(4) NOT NULL AUTO_INCREMENT, -> `name` varchar(25) NOT NULL, -> PRIMARY KEY (`id`) -> ); Query OK, 0 rows affected (0.04 sec) ...
SQL TRUNCATE Statement ExampleTo delete all the rows from employee table, the query would be like, TRUNCATE TABLE employee; Difference between DELETE and TRUNCATE Statements:DELETE Statement: This command deletes only the rows from the table based on the condition given in the where clause or ...
obclient [OBORACLE]> alter table OBORACLE.F2 disable constraint FK_ID; Query OK, 0 rows affected (0.056 sec) 再次truncate 表操作。 obclient [OBORACLE]> truncate table f1; ORA-00600: internal error code, arguments: -5594, Cannot truncate a table referenced in a foreign key constraint (`...