Archive for the ‘Unix’ Category
I have been DBA-ing for a while now, and I today I used a “new” command which I have never used in the previous 20+ years I have worked with Oracle: DROP DATABASE. It’s amazing what you miss sometimes!
So, what does it do? As the name implies, it drops the database. That is, it deletes all of your database files. This is significantly safer than using traditional Operating System methods (assuming you even have access and are not using ASM), and for added safety you have to be running the database in RESTRICT MOUNT mode.
What a lovely command. It goes to all the trouble of locating and removing those troublesome files that were put into the wrong place by another DBA that you would have missed if cleaning up manually.
It certainly made the pre-production clone script (cloning from the Physical Standby) that I have just written quite a bit easier to code.
Does anybody know if there is any other reason for running the database in RESTRICT MOUNT mode, or was it designed just for this command?
EDIT: I was just informed via Twitter (@chandlerdba) by
@pfierens that this also takes out your SPFILE. If you are using an SPFILE (you should be!) and want to keep your db parameters for a db rebuild, I would recommend creating a pfile from the spfile first…
Has anyone ever done an RMAN “drop database including backups” ? You REALLY need to be sure you don’t want it back to run that one!
There can be few scientists who have contributed so much to the world as Dennis Ritchie. Completely anonymous to the world at large, and to far too much of the computing fraternity too, his involvement in the development of C – the first portable programming language, and Unix cannot be understated. Who uses Unix? Well, everybody. What is the O/S on embedded devices? What did Steve Jobs base his Mac O/S and Mobile Operating systems on? Upon what did Bill Gates base the operating system for the new IBM PC in 1980? What do corporations across the world use to power their servers? What is it all built on? Unless you’re running some proprietary mainframe software, the building blocks of what you are using were set, to some degree, by Dennis Ritchie.
Whilst I never met him myself I did work with his sister, Lynn, for several years at a software house in the North East of England, where she still resides. She told me some of the stories about him; how the invention of C and Unix were really aims in making computing more portable, more standard, easier to use. How all that Ritchie, Ken Thompson, Brian Kernighan and the others got for this was their salary [although they did make a few quid on top out of their books ], and the ability to distribute Unix free, with C, to all and sundry as Bell labs, a subsidiary of AT&T, had no financial interest in computing as they were a regulated telephone monopoly at the time.