Oracle Flashback Technologies-Estimating the amount of flash logs generated at different time periods
V$flashback_database_stat
A statistic that monitors the I/O overhead of the flashback data and estimates the flashback space requirement based on the previous system load. The time interval is one hour.
Sql> SELECT * from V$flashback_database_stat order by Begin_time; Begin_tim end_time flashback_data db_data redo_data estimated_flashback_size------------------------ ----------------------------------------------------23-jun-15 23-jun-15 5144576 26615808 1989120 26849280023-jun-15 23-jun-15 8192 106496 1536 0sql>
V$flashback_database_stat description
Column |
Datatype |
Description |
Begin_time |
DATE |
Beginning of the time interval |
End_time |
DATE |
End of the time interval |
Flashback_data |
Number |
Number of bytes of flashback data written during the interval |
Db_data |
Number |
Number of bytes of database data read and written during the interval |
Redo_data |
Number |
Number of bytes of redo data written during the interval |
estimated_flashback_size |
number |
Value of estimated_flashback_size in V$flashback_database_log at the end of the time interval |
con_id |
Number |
The ID of the container to which the data pertains. Possible values include:
- 0: This value was used for rows containing data, pertain to the entire CDB. This value was also used for the rows in Non-cdbs.
- 1: This value was used for rows containing data, pertain to only the root
- n: Where n is the applicable container ID for the rows containing data
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Oracle Flashback Technologies-Estimating the amount of flash logs generated at different time periods