On Aug 6, 2010, at 9:59 PM, Tom Lane wrote:
> It's not immediately clear to me what an ordered-pair type would get you
> that you don't get with 2-element arrays.
Just syntactic sugar, really. And control over how many items you have (a bounded pair rather than an unlimited element
array).
> A couple of quick experiments suggest that 2-D arrays might be the thing
> to use. They're easy to construct:
>
> regression=# select array[[1,2],[3,4]];
> array
> ---------------
> {{1,2},{3,4}}
> (1 row)
>
> and you can build them dynamically at need:
>
> regression=# select array[[1,2],[3,4]] || array[5,6];
> ?column?
> ---------------------
> {{1,2},{3,4},{5,6}}
> (1 row)
>
> This is not exactly without precedent, either: our built-in xpath()
> function appears to use precisely this approach for its namespace-list
> argument.
Agreed.
Best,
David