Re: [HACKERS] GSoC 2017: Foreign Key Arrays

Mark Rofail wrote:
> On Wed, Jul 12, 2017 at 2:30 PM, Mark Rofail <markm.rofail@gmail.com> wrote:
> 
> > On Wed, Jul 12, 2017 at 12:53 AM, Alvaro Herrera <alvherre@2ndquadrant.com
> > > wrote:
> >>
> >> We have one opclass for each type combination -- int4 to int2, int4 to
> >> int4, int4 to int8, etc.  You just need to add the new strategy to all
> >> the opclasses.
> >>
> >
> > Can you clarify this solution ? I think another solution would be external
> > casting
> >
> If external casting is to be used. If for example the two types in
> question are smallint and integer. Would a function get_common_type(Oid
> leftopr, Oid rightopr) be useful ?, that given the two types return the
> "common" type between the two in this case integer.

Do you mean adding cast decorators to the query constructed by
ri_triggers.c?  That looks like an inferior solution.  What problem do
you see with adding more rows to the opclass?

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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