TRUNCATE是 MySQL 中的一个 SQL 命令,用于快速删除表中的所有数据,但不删除表本身。这个命令比DELETE更快,因为它不会记录单个行的删除操作,也不会触发任何删除触发器。 基础概念 TRUNCATE TABLE: 这个命令会移除表中的所有行,但保留表的结构、列、约束和索引。
The redshift truncate command is used to erase all the records in a table. While the delete statement is used to remove records from a table, it may not be efficient for large tables. Thus, the truncate command command is used to delete all data from a table. Unlike the delete statement...
SQL> insert into tbl_a values(1, 'a'); 1 row created. SQL> commit; Commit complete. SQL> truncate table tbl_a; truncate table tbl_a * ERROR at line 1: ORA-02266: unique/primary keys in table referenced by enabled foreign keys 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 此时...
F5执行,如图: 参考:http://blog.sqlauthority.com/2010/03/04/sql-server-rollback-truncate-command-in-transaction/ --EOF-- Author:兴百放 Web:http://xbf321.cnblogs.com/ Time:2010.3.12
TRUNCATE statement: This command is used to delete all the rows from the table and free the space containing the table.SQL DROP Statement:The SQL DROP command is used to remove an object from the database. If you drop a table, all the rows in the table is deleted and the table ...
Executed in 0 seconds SQL> select count(*) from mytest; --表已经空了,但没有想象中快速完成查询,用时57秒,这不大正常,但证明HWM确实没有下去,在执行不必要的空块读取 COUNT(*) --- 0 Executed in 57.046 seconds SQL> truncate table mytest; --TUNCATE重置HWM,扫描数据块大大降低,很快过去 Table...
EXCHANGE PARTITION. // *Action: Before performing the above operations the table, disable the // foreign key constraints in other tables. You can see what // constraints are referencing a table by issuing the following // command: // SELECT * FROM USER_CONSTRAINTS WHERE TABLE_NAME = "tab...
Now issue the following command to truncate these rows. 现在,执行以下命令删除这些行。 The TRUNCATE SQL statement is now supported for fast deletes. 现在支持用于快速删除的TRUNCATE sql语句。 We are going to truncate the Trace message in this situation. 我们将截断在这种情况下的跟踪信息。 The...
"change to default in_place method"; } 新加一个innodb的create接口,提供外部传入trx, 这样它就可以和rename共用一个trx修改字典表了 ha_innobase::drop_with_create_to_truncate() { DBUG_ENTER("ha_innobase::drop_with_create_to_truncate");
You should consider about using Truncate table statement in your Pl/SQL code. Truncate table have better performance but you cannot rollback data after truncate. Truncate table can be executed in combination with EXECUTE IMMEDIATE command in Pl/SQL code. ...