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Restart Database Command
Sometimes the DBA just want to restart a database to enable a parameter value or change the pfile to spfile, or things like that. For these cases the is actually needed to shutdown database than startup the database. But it could have a ‘restart’ command to automatically make the shutdown/startup with parameters. Thinking like that, it can have ‘levels’ of restart, to avoid all process of checkpoint, flush data to disk, switch log file, and etc OR instance recover (in case of abort) like:
1. Complete Restart (similar to actual shutdown/startup):
SQL> RESTART COMPLETE
ORACLE instance shut down.
ORACLE instance started.
Total System Global Area 812529152 bytes
Fixed Size 2264280 bytes
Variable Size 960781800 bytes
Database Buffers 54654432 bytes
Redo Buffers 3498640 bytes
2. Quick Restart (kill all sessions and restart PMON, SMON, and others, but not flush data to disk neither refresh SGA structure):
SQL> RESTART QUICK
Background Processes Restarted.
It might be combined to the current syntax used by SHUTDOWN or STARTUP, examples:
SQL> RESTART QUICK ABORT; -- (shutdown with abort)
SQL> RESTART COMPLETE [NO]MOUNT; -- (shutdown and startup database nomounted or mounted state only)
SQL> RESTART QUICK ABORT SPFILE=‘/new/location/pfile’; -- (shutdown abort and start with other SPFILE)
Another advantage is to enable QUICK RESTARTS to activities like enable or disable ARCHIVELOG, FLASHBACK and other things that, I think, not necessary demands a COMPLETE instance restart.
Other databases like MySQL have this kind of implementation and it’s very useful.
Gerald Venzl-Oracle Senior Principal Product Manager San FranciscoMember, Moderator Posts: 85 Employee
How is that different from SHUTDOWN and STARTUP today except that the DBA has to type two commands rather than one?
Both of those commands do already offer several levels of operation.
One can even Suspend and Resume a Database but that is off topic for this idea.
>>Other databases like MySQL have this kind of implementation and it’s very useful.
Useful in which situations?
I think this would only be used by inexperienced administrator. In the sense of: Hm... something is wrong with my database, I don't know what to do, let's restart it.
But they can even do it now using the windows services panel.
I hope the majority or Oracle DBAs does not fall into this category.
The need to restart a database should be very very rare. In most cases it is requried because some major administrative atsks are neccessary. In that case things are to do between shutdown and startup. Maybe a startup in restricted mode, applying some patch or whatever.
I'd also have the command know the current state of the database and startup to that level. For example, standby databases are in MOUNT mode and the RESTART should bring back to MOUNT mode.
Franck Pachot OCM 12c DBA Oracle ACE Director and Oak Table member SwitzerlandMember Posts: 912 Bronze Trophy
Your 'RESTART COMPLETE' is actually possible with 'STARTUP FORCE' if you trust instance recovery...
Your 'RESTART QUICK' is actually possible with 'STARTUP FORCE' in a Pluggable Database as there's no instance to shut down.
I don't see how this can add value. I prefer what's currently in place.