Re: GSoC 2017: Foreign Key Arrays

Mark Rofail wrote:

> - now the RI checks utilise the @>(anyarray, anyelement)
> - however there's a small problem:
> operator does not exist: integer[] @> smallint
> I assume that external casting would be required here. But how can I
> downcast smallint to integer or interger to numeric automatically ?

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.

BTW now that we've gone through this a little further, it's starting to
look like a mistake to me to use the same @> operator for (anyarray,
anyelement) than we use for (anyarray, anyarray). I have the feeling
we'd do better by having some other operator for this purpose -- dunno,
maybe @>> or @>. ... whatever you think is reasonable and not already
in use. Unless there is some other reason to pick @> for this purpose.

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