json_populate_recordset

 From here:

https://www.postgresql.org/docs/10/static/functions-json.html

select * from json_populate_record(null::myrowtype, '{"a": 1, "b": ["2", 
"a b"], "c": {"d": 4, "e": "a b c"}}')

What is the null::myrowtype doing?


Thanks,
-- 
Adrian Klaver
adrian.klaver@aklaver.com