Re: Making jsonb_agg() faster

I wrote:
> Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com> writes:
>> You left two “ugly hack” comments. Maybe add a short description for why they are hack and what can be improved in the future.

> It's the same ugly hack as before, I just formatted the code more
> legibly ... I didn't stop to look at whether there's a better way to
> do it. Again, that seems like material for a different patch.

I took another look at that code and decided that it wasn't quite
as bad a hack as I first thought: it's relying on the upcoming
JsonbValueToJsonb call to wrap the scalar value into the right
array structure for a "raw scalar" JSONB. Improving the comments
about what this code is doing is definitely within the charter of
my 0001 patch, so here's a new version that improves those two
comments. Otherwise this is the same as v3.

regards, tom lane