The idea of converting a JSONB array to a PG array is appealing and would potentially be more general-purpose than adding a new unnest. I'm not sure how feasible either suggestion is.
I will say that I think the current state of affairs is gratuitously verbose and expects users to memorize a substantial number of long function names to perform simple tasks. -p On Tue, May 31, 2016 at 2:06 PM, David G. Johnston < david.g.johns...@gmail.com> wrote: > On Tue, May 31, 2016 at 4:34 PM, David Fetter <da...@fetter.org> wrote: > >> Folks, >> >> While querying some JSONB blobs at work in preparation for a massive >> rework of the data infrastructure, I ran into things that really >> puzzled me, to wit: >> >> SELECT * FROM unnest('["a","b","c"]'::jsonb); >> ERROR: function unnest(jsonb) does not exist >> >> SELECT * FROM jsonb_array_elements('["a","b","c"]'::jsonb); >> value >> ─────── >> "a" >> "b" >> "c" >> (3 rows) >> >> > I'd be inclined to -1 such a proposal. TIMTOWTDI is not a principle that > we endeavor to emulate. > > Having an overloaded form: <unnest(jsonb) : setof jsonb> is unappealing. > While likely not that common the introduction of an ambiguity makes raises > the bar considerably. > > That said we do seem to be lacking any easy way to take a json array and > attempt to convert it directly into a PostgreSQL array. Just a conversion > is not always going to succeed though the capability seems worthwhile if as > yet unasked for. The each->convert->array_agg pattern works but is likely > inefficient for homogeneous json array cases. > > David J. > -- Peter van Hardenberg San Francisco, California "Everything was beautiful, and nothing hurt."—Kurt Vonnegut