U kunt JSON_TABLE gebruiken:
SELECT
id, var1, count(sub_id) subvalues
FROM
JSON_TABLE (
to_clob('{ id: 123, var1: "abc", subvalues : [{ id: 1, value: "a", }, { id: 2, value: "b" } ]}'),
'$'
COLUMNS (
id NUMBER PATH '$.id',
var1 VARCHAR PATH '$.var1',
NESTED PATH '$.subvalues[*]'
COLUMNS (
sub_id NUMBER PATH '$.id'
)
)
)
GROUP BY id, var1