This example uses the READ_NOS table operator with JSON_KEYS function to display the keys in a JSON file.
If not already done, create the authorization object. See Example: Create an Authorization Object.
Perform the READ_NOS:
SELECT DISTINCT * FROM JSON_KEYS ( ON ( SELECT payload FROM ( LOCATION='/s3/td-usgs-public.s3.amazonaws.com/DATA/09380000/2018/06/27' AUTHORIZATION=MyAuthObj ) AS read_nos_query ) AS json_on_keys_query ) AS d ;
Result:
JSONKeys --------------- "Flow" "Precipitation" "Conductance" "datetime" "site_no" "Temp" "GageHeight"