Re: can i know old value for a parameter ?

On Oct 14, 8:34 am, romantic..._at_gmail.com wrote:
> hi all,
> let's say a parameter changed in the database
> ex:
> alter system set retention_target=1500;
> and i want to know what was the old value before it has been changed ,
> is there any way to know?
> thanks for reading.

Yes, certainly. It's called a change control mechanism, such as Subversion, and you can use it to check the value for any parameter at any time in the past. The only requirement, of course, is that you know how to set up a subversion repository and religiously use it to control all manner of configuration changes on your servers!

I'm being slightly flippant: but only slightly. There is no mechanism *within Oracle* to see what parameters used to be in the past. You can only do that sort of thing *outside* of Oracle by using standard change control mechanisms. Some people used to add comments to the init.ora's, but it's a practice I abhor: it turns what ought to be neat, compact and tidy configuration file into a long-winded essay. Similarly, there is a facility for adding a comment when editing an spfile (alter system set parameter=value scope=spfile comment=something or other), but I wouldn't recommend it: the next time you change the parameter, the old comments are lost (so it's not a change **history**). It's much better, in my view, to see your request in the context of all such requests: how do we keep track of configuration changes we make to our databases, our servers, our network, our hardware, our SOE... these all need proper documentation in some sort of change control mechanism.

In the past, I've used Visual Source Safe and Subversion for that sort of thing: storing spreadsheets, word documents and text files in such repositories is fine. These days, I like to use the Dizwell Server for the same job (see: http://www.dizwell.com/prod/node/694), because a blog-type application is actually not a bad way of documenting changes to files which happen over time -and you get to explain the changes and link them to related changes, instead of merely just recording them sequentially. Received on Sat Oct 13 2007 - 17:55:14 CDT