Is Truncate a DDL command or DML command? Is UNION ALL a costly query? Is WITH (HOLDLOCK) still needed for using MERGE as an upsert ISNULL not working??? ISNULL(DISTINCT... isnumeric/isdate in a case statement doesnt do what i thought it would Issue When Converting sql_variant to nv...
http://www.cnblogs.com/8765h/archive/2011/11/25/2374167.html delete 语句是数据库操作语言(dml) drop、truncate都是DDL语句(数据定义语言),执行后会自动提交。
Truncate is a DDL, Truncate does not modify the data. Truncate never touches the data, thats a misconception. In every instance of SQL Truncate does the same thing, it simply marks the extents and lets them know the pages are to be reused (deallocated). The pages then (after commit) ...
1、truncate是DDL,会隐式提交,所以,不能回滚,不会触发触发器。 2、truncate会删除表中所有记录,并且将重新设置高水线和所有的索引,缺省情况下将空间释放到minextents个extent,除非使用reuse storage,。不会记录日志,所以执行速度很快,但不能通过rollback撤消操作(如果一不小心把一个表truncate掉,也是可以恢复的,只是...
RENAMEis used to modify the name of a database table. TRUNCATEis used to quickly remove all records from a table, while preserving its full structure so it can be reused later. Explore thedifference between DDL and DML.
as we can see, truncate sql is ignored deliberately. however drop table xx will be passed by and stored. what is the reason for this implementation? maxwell/src/main/java/com/zendesk/maxwell/schema/ddl/SchemaChange.java Line 43 in 222712d SQL_BLACKLIST.add(Pattern.compile("\\A\\s*TR...
@@ -685,6 +691,10 @@ func onTruncateTable(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64, _ erro // Clear the TiFlash replica available status. if tblInfo.TiFlashReplica != nil { e := infosync.DeleteTiFlashTableSyncProgress(tblInfo.ID) if e != nil { logutil.BgLogger(...
Is Truncate a DDL command or DML command? Is UNION ALL a costly query? Is WITH (HOLDLOCK) still needed for using MERGE as an upsert ISNULL not working??? ISNULL(DISTINCT... isnumeric/isdate in a case statement doesnt do what i thought it would Issue When Converting sql_variant to nv...
Is Truncate a DDL command or DML command? Is UNION ALL a costly query? Is WITH (HOLDLOCK) still needed for using MERGE as an upsert ISNULL not working??? ISNULL(DISTINCT... isnumeric/isdate in a case statement doesnt do what i thought it would Issue When...
用来存放可以被恢复的信息. 如果你没有COMMIT事务,ORACLE会将数据恢复到删除之前的状态(准确地说是恢复到执行删除命令之前的状况) 而当运用TRUNCATE时, 回滚段不再存放任何可被恢复的信息.当命令运行后,数据不能被恢复.因此很少的资源被调用,执行时间也会很短. (译者按: TRUNCATE只在删除全表适用,TRUNCATE是DDL不...