例 - Teradata Database - Teradata Vantage NewSQL Engine - KEYCOUNTの例です。

SELECT new JSON('{"name":"will","occupation":"engineer","disposition":"silly"}')
.keycount();

 *** Query completed. One row found. One column returned.
 *** Total elapsed time was 1 second.

 NEW JSON('{"name":"will","occupation":"engineer","disposition":"silly"}',
---------------------------------------------------------------------------
                                                                          3