Re: Editing Views with EditGrid

On Tue, May 6, 2008 at 9:05 PM, Andreas Neumann <a(dot)neumann(at)carto(dot)net> wrote:
> Hi Dave,
>
> Thank you for letting me know about the situation. Can you estimate how
> much work it would be to implement editable views? Maybe based on the
> experience with the editable tables? Maybe we can find a few interested
> parties paying for the development of this feature?

The problem with editing views is not the editing (the code for the
tables will do the job just fine with a few minor changes in most
cases). The problem comes where you have rules which implement
non-trivial updates - for example; consider a view with a total
column, an item price, and a quantity. If you update the quantity,
there is no straightforward way for pgAdmin to understand that the
total price will be automatically updated. In fact, it won't even know
that the total column cannot be manually edited.

This gets even worse, because the rules may easily affect different
rows from that being edited, or even entirely unrelated data. The only
safe way to manage that that I can see would be to refresh the entire
data set following each edit - and that would be unusably slow.

I'm happy to entertain proposals that might work, but this a
non-trivial problem, caused largely by Postgres' superior flexibility
compared to most other DBMSs. It isn't gonna be easy to fix.

--
Dave Page
EnterpriseDB UK: http://www.enterprisedb.com