See http://www.postgresql.org/docs/8.1/static/ddl-inherit.html as well as http://www.postgresql.org/docs/8.1/static/sql-createtable.html

This functionality is absent in Oracle. In case of a single parent it may be mimicked by resorting to object types, but for multiple parent - nope.

Anyhow, its implementation in current version of PostgreSQL has major drawbacks (see Caveats section in the first link).

Yes, a view can do the trick - almost...
As each time you add a new child table (or grand-child, or grand-grand-child) you need to modify your view (or views).

So it is doable - but require additional maintenance efforts.

object views allow you to add new child in this hierarchy without original view modification. Just use "under {parent view}" clause while creating object view for the child. Though you are not explicitly modifying the original parent view - it will be altered behind the scene to include child view in this case.

what is responsibility,,,profile options in oracle apps?what are iys functionalities?

It is a kind of a "resorting to object types" which I have mentioned in my post. But even this solution does not mimic PostgeSQL functionality completely:

- You cannot inherit from 2 or more parents (in PostgeSQL you can)
- You need to duplicate definition of all columns by a child creation
- changes to the parent table structure are not automatically reflected in its childs
- You need to use 2 commands (create table + create view) instead of single create table.

And so on.

I'd say i LOVE how object features are implemented in Oracle. They were able to clearly separate them from regular relational DB nature. I'd say - how it is handled in postgres is at least not mature (if not useless).
As for inheriting from more than one parent - I believe multiple inheritance is more evil than benefit. Not surprisingly that pretty much all modern languages got rid of it and switch to interface implementation.
In Oracle - if you want you can use even tables of object types, but object views are MUCH more powerful and convenient way of working with OOO features. To be honest, all I care for OOO - polymorphism. And Oracle allows us to have it in a very elegant way in DB. We are using these features VERY heavily and are pretty happy with them.

I suppose, if you really wanted to mimic postgreSQL functionality for this, you could write a proc that would modify the view when a child table was created. Then call it through a DDL trigger. Or at end-of-day, just rebuild it automatically.

1. You completely mixed up behavior inheritance and data structure inheritance. In case PostgerSQL we have later only.
2. As for multiply inheritance - what you are writing reflects quite outdated state (Java and alike), most really modern languages support mix-ins or similar constructs.