Delete all the data in schema objects without removing the structure of these objects (TRUNCATE). Note: UnlikeDELETE,TRUNCATEgenerates noundo data, which makes it faster thanDELETE. Also,TRUNCATEdoes not invoke delete triggers Grant and revoke privileges and roles (GRANT,REVOKE). ...
Phase 2: Steps to Delete Rows for this SQL UNDO Last Command Task Step 1:-Now we will delete some rows which we have created earlier and recover later using LSNs available in the Transaction log. We will delete first 9 entries in the row. The results will show that the first9 (less ...
Yes, if the database management system supports transactions and if the DELETE statement is executed within a transaction, you can rollback the transaction to undo the effects of the DELETE operation. What are some alternatives to using the DELETE statement for data removal? Depending on the scen...
DELETE STATISTICS deletes any statistics about the analyzed object that are currently stored in the data dictionary. Use this statement when you no longer want Oracle to use the statistics. When you use this clause on a table, Oracle also automatically removes statistics for all the table's...
行撤銷刪除通知 DBPROP_NOTIFYROWUNDODELETE 數據列復原插入通知 DBPROP_NOTIFYROWUNDOINSERT 數據列更新通知 DBPROP_NOTIFYROWUPDATE 數據列集擷取位置變更通知 DBPROP_NOTIFYROWSETFETCHPOSITIONCHANGE 數據列集發行通知 DBPROP_NOTIFYROWSETRELEASE 向後捲動 DBPROP_CAN...
During a backup, most operations are possible; for example, INSERT, UPDATE, or DELETE statements are allowed during a backup operation. Operations that cannot run during a database or transaction log backup include: File management operations such as the ALTER DATABASE statement with either the ...
{ AES_128 | AES_192 | AES_256 | TRIPLE_DES_3KEY } , encryptor_options ) <encryptor_options> ::= SERVER CERTIFICATE = Encryptor_Name | SERVER ASYMMETRIC KEY = Encryptor_Name <log_specific_options> [ ,...n ]::= --Log-specific Options { NORECOVERY | STANDBY = undo_file_name } |...
Exclusive (X) Used for data-modification operations, such as INSERT, UPDATE, or DELETE. Ensures that multiple updates cannot be made to the same resource at the same time. Intent Used to establish a lock hierarchy. The types of intent locks are: intent shared (IS), intent exclusive (IX)...
HADR_RECOVERY_WAIT_FOR_UNDO 数据库恢复正在等待辅助数据库完成恢复和初始化阶段以便恢复到主数据库的公共日志点。 这是故障转移后的预期等待。 可以通过 Windows 系统监视器(perfmon.exe)和 DMV 跟踪撤消进度。适用于:SQL Server 2012 (11.x) 及更高版本。 HADR_REPLICAINFO_SYNC 等待并发控制更新当前副本状态。
undo log和redo log记录物理日志不一样,它是逻辑日志。可以认为当delete一条记录时,undo log中会记录一条对应的insert记录,反之亦然,当update一条记录时,它记录一条对应相反的update记录。当执行rollback时,就可以从undo log中的逻辑记录读取到相应的内容并进行回滚。 Undo log销毁:undo log在事务执行时产生,事务...