问题
I'm using Oracle Database 11.2.
I have a scenario where I issue FLASHBACK DATABASE quite often.
It seems that a FLASHBACK DATABASE cycle does a reboot of the database instance which takes approx. 7 seconds on my setup.
Database is small (~ 1 GB tablespace), all files should be in I/O caches/buffers. Therefore I think that the bottleneck is not I/O based.
I'm looking for tuning advices in order to save user time and/or CPU time for doing a flashback.
UPDATE:
Flashback sequence (and timing of each step) is the following:
1. Get SYSDBA connection with prelim_auth=true [15 ms]
2. SHUTDOWN ABORT; [1034 ms]
3. STARTUP (unrestricted) [1241 ms]
4. Close SYSDBA connection [2 ms]
5. Get SYSDBA connection with prelim_auth=false [18 ms]
6. ALTER DATABASE MOUNT [4073 ms]
7. FLASHBACK DATABASE TO RESTORE POINT <restore_point_name> [306 ms]
8. ALTER DATABASE OPEN RESETLOGS [1652 ms]
9. CLOSE SYSDBA connection [2 ms]
来源：https://stackoverflow.com/questions/56526595/tune-oracle-database-for-faster-startup-flashback