count occurrences of array values in postgres using hstore

gistfile1.sql

SELECT hstore(array_agg(v), array_agg(c::text)) FROM (
SELECT v, COUNT(*) as c ,1 as agg from  unnest(ARRAY['foo','bar','baz','foo']) v GROUP BY v) t
GROUP BY agg

--> "bar"=>"1", "baz"=>"1", "foo"=>"2"

YES