On Wednesday, September 24, 2014, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Raj Gandhi <raj01gandhi@gmail.com> writes: > SQL with VARIADIC also gives the same error in 9.1: > select format('%s %s', VARIADIC array_agg(val)) > from (values ('1'),('2')) src (val) > == > ERROR: too few arguments for format
You need 9.3 or later for that to work. Per the 9.3 release notes:
* Allow concat() and format() to properly expand VARIADIC-labeled arguments (Pavel Stehule)
This whole feature could maybe be made more visible in the 9.3 documentation but (arguably) since it was a feature and not a bug fix back patching was not possible. Specifically it seems like it was too invasive a change to make it work properly in the back branches.