Re: Thoughts about updateable views

Tom Lane wrote:
> Bernd Helmle <mailings@oopsware.de> writes:
> > a) Definition of an updateable view?
> 
> > The first thing what i thought about was, what defines a updateable view. 
> 
> The SQL spec clearly defines the requirements for a view to be
> updateable.  It seems sufficient to me to handle the cases required by
> the spec.
> 
> > b) The creation of an automatic INSERT/UPDATE or DELETE Rule had to be done 
> > with
> > the creation of the SELECT Rule. I understand how PostgreSQL handles views 
> > with its Rule
> > System, but what happens when no appropiate Rule can be created?
> 
> You don't create it.  This corresponds to the view not being updateable.
> AFAICS the spec expects CREATE VIEW to create both kinds of view without
> the implementation making any particular comment about it.
> 
> We might need to mark automatically created rules as such, and be
> prepared to drop them if the user then defines a manually-created rule.
> Otherwise we will have backwards-compatibility problems with existing
> databases.

I was thinking we create an updatable view if possible, and throw an
error if they try to insert/update/delete into a non-updatable view. 
Right now we ignore such activity, but that seems wrong.

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