Re: json accessors

On 12/05/2012 12:14 PM, David E. Wheeler wrote:
> On Nov 28, 2012, at 4:10 PM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
>
>>> Yes, it's iterative. And for deeply nested json it might be somewhat
>>> inefficient, although the parser is pretty fast AFAICT. But it's a start.
>> not completely buying that: see comments below. not supporting xpath
>> style decompositions seems wrong to me. IOW, json_get should be set
>> returning (perhaps via wild cards in the keytext) or we need
>> json_each.
> The problem I see with the current proposal is that this limitation, it seems to me, would prevent the ability to index nested keys. If you're essentially composing and decomposing JSON values as you drill down, the intermediate JSON values between the original one and the final return value can't be indexed, can they?
>
> For sufficiently large columns, I expect I would want a GIN index to speed JSON value extraction queries. Possible with this proposal?

Probably not.

cheers

andrew