Accidental deletion and data recovery of Oracle learning notes

Note: When I changed the bug, I accidentally deleted a piece of data from the generated database, so I was shocked and found it again.

You can use the following methods to delete a file:

Use the followingCommand to view the current database ParametersUndo_retention.

 
Show parameter undo;
 

Shown as follows:

 
Undo_managementStringAuto
Undo_retention integer900
Undo_tablespaceStringUndotbs1
 

Undo_retention (Persistence),The Unit is 900 seconds. 15Minutes.

Modify the defaultUndo_retentionParameter settings:

 
AlterSystemSetUndo_retention=10800Scope=Both;
 

1.If the data is deleted

For example:

Select * FromOrder_listAs Of TimestampTo_timestamp ('2013-05-29 09:33:00','Yyyy-mm-dd hh24: MI: SS')WherePop='20130319016';
 

Then the flashback data is inserted into the table again:

Insert IntoOrder_list (Select * FromOrder_listAs Of TimestampTo_timestamp ('2013-05-29 09:33:00','Yyyy-mm-dd hh24: MI: SS')WherePop='20130319016');
 

 You can also create a temporary table to restore all data to the temporary table.

The above time point is the time before accidental deletion, preferably very close to the time

2. If the table is deleted

Restore the deleted base table

 
FlashbackTableTable NameToBeforeDrop;