Oracle associated with Flashback Database view

1. V$database

This view lets you see if the Flashback database feature is enabled

Sql> select flashback_on from V$database;

flashback_on

------------------

YES

2. V$flashback_database_log

The earliest time flashback database can be rolled back, depending on how much of the reserved flashback database Log, the view can view a lot of useful information.

Oldest_flashback_scn/oldest_flashback_time: These two columns are used to record the earliest possible point of return.

Flashback_size: Records the size of the currently used Flash Recovery area space

Retention_target: System-defined policies

Estimated_flashback_size: Estimates of the size of space required based on policy

sql> Select Oldest_flashback_scn os, to_char (Oldest_flashback_time, ' Yy-mm-dd HH2

4:mi:ss ') OT, Retention_target rt,flashback_size FS, estimated_flashback_size ES

From V$flashback_database_log;

OS OT RT FS ES

----------  -----------------     ----------  ----------    ----------

946088 09-10-14 13:49:59 1440 16384000 350920704

3. V$flashback_database_stat

This view is used to make more fine-grained records and estimates of the flashback log space. This view records the amount of activity of the database in hours per unit time, Flashback_data represents the number of flashback log, Db_date represents the number of data changes, Redo_date represents the number of logs, which can reflect the activity characteristics of the data by these 3 numbers, More accurate projected space requirements for Flash Recovery area

Sql> alter session set nls_date_format= ' Hh24:mi:ss ';

The session has changed.

sql> Select *from v$flashback_database_stat;

Begin_ti end_time flashback_data db_data redo_data estimated_flashback_size

-------- -------- -------------- ---------- ---------- ------------------------

14:43:10 15:15:28 6455296 29310976 3898368 0

Author: 51cto Blog Oracle Little Bastard

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