Dealing with the urgent case oracle database is stuck

My colleague asked for help from me a couple of days ago, the case was very urgent because oracle database rac 19.14 was stuck along with the business had been affected. As an oracle database second line technical support I joined Tencent Meeting by the meeting number the colleague sent and subsequently controlled his computer to do some troubleshooting work. Finally I found out the root cause of stuck is that the oracle recovery area is full, yes, it’s a classic and common space issue for oracle database.

Hence I’ll share how to tackle the urgent issue with you in this blog note.

How to purge oracle flashback logs

As well-known as the oracle flashback logs have been saved to disk by undo entries from undo tablespace, which is same as the archived logs (offline redo logs) have been saved to disk by redo entries from online redo logs. Oracle flashback logs have been disabled by default because the value of column flashback_on is NO from v$database. Once we enabled the function of oracle flashback database by “alter database flashback on” in SQL*Plus oracle started generating flashback logs at that moment. In general oracle flashback logs have been saved to Flash Recovery Area (also known as Fast Recovery Area) hence we check parameter “db_recovery_file_dest” and “db_recovery_file_dest_size” respectively so that we’re able to acquire the location and space size of FRA (Flash Recovery Area), furthermore we can also know the location of oracle flashback logs but we can’t accurately know the space size of flashback logs because there exists the extra type of files on FRA.

After the brief description about oracle flashback log above I’ll share how to purge oracle flashback logs with you in this blog note.