Saturday, 30 August 2014

Virtual Private Database (Part 1)

Views

When working with views you have several options to hide some of the data. In the article on views I have told you about the way to hide columns from the table. By adding a predicate (where clause) to the view, you can restrict the rows a user sees. This would imply creating different views for different (groups of) users. If you have an interface built to interact with the data, that would also mean you have to maintain multiple versions of these interfaces. Not a big problem if you only have a small number (like two or three) interfaces to maintain, but if the number of interfaces grows, chances are that you will forget to implement changes in one or more of them.

Saturday, 23 August 2014

Should you install or clone Oracle Home?

What is cloning?

Cloning is a process of copying an existing installation to a different server or location. Cloning is similar to an Oracle installation except Oracle universal installation performs the actions in a special mode called “clone mode”.

Starting from 10g onwards, Oracle supports cloning and users can easily clone existing Oracle installations. The source and destination servers should have same configuration and packages installed in order Oracle cloning to work.  The cloning process works by copying all files from the source Oracle home to the destination Oracle home, and files which are not part of the source instance will not be copied to the destination location.