[MDEV-25155] JSON_TABLE: Status variable Feature_json is not incremented - Jira

XML

Word

Printable

bb-10.6-mdev17399-psergey2 8b533cc1d5
MariaDB [test]> show status like '%json%';
+---------------+-------+
\| Variable_name \| Value \|
+---------------+-------+
\| Feature_json \| 0 \|
+---------------+-------+
1 row in set (0.001 sec)

MariaDB [test]> select * from json_table('{}', '$' columns (o for ordinality)) t;
+------+
\| o \|
+------+
\| 1 \|
+------+
1 row in set (0.000 sec)

MariaDB [test]> show status like '%json%';
+---------------+-------+
\| Variable_name \| Value \|
+---------------+-------+
\| Feature_json \| 0 \|
+---------------+-------+
1 row in set (0.001 sec)

The status variable is not dead, it's updated when JSON functions are used:

MariaDB [test]> select json_valid(1);

+---------------+

| json_valid(1) |

+---------------+

|             1 |

+---------------+

1 row in set (0.000 sec)

MariaDB [test]> show status like '%json%';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| Feature_json  | 1     |

+---------------+-------+

1 row in set (0.001 sec)

The variable is defined in the documentation as

Number of times JSON functionality has been used, such as one of the JSON functions

JSON_TABLE definitely counts as "JSON functionality".

relates to

MDEV-17399 Add support for JSON_TABLE