AW: Re: postgres TODO

> Thus spake Alessio Bragadini
> > > > * Add function to return primary key value on INSERT
> > >
> > > I don't get the point of this. Don't you know what you
> inserted? For
> > > sequences there's curval()
> >
> > Mmmhhh... it means that we can assume no update to the
> sequence value
> > between the insert and the curval selection?
>
> We can within one connection so this is safe but there are
> other problems
> which I am not sure would be solved by this anyway. With
> rules, triggers
> and defaults there are often changes to the row between the
> insert and the
> values that hit the backing store. This is a general problem of which
> the primary key is only one example.
>
> In fact, the OID of the new row is returned so what stops one
> from just
> using it to get any information required. This is exactly
> what PyGreSQL
> does in its insert method. After returning, the dictionary
> used to store
> the fields for the row have been updated with the actual
> contents of the
> row in the database. It simply does a "SELECT *" using the new OID to
> get the row back.

OID access is not indexed by default, only if the dba created a
corresponding
index. Thus OID access is a seq scan in a default environment.

Andreas