Re: Initial review of xslt with no limits patch

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