SQL JSON_OBJECT() function results in RUNTIME_FAILURE when querying INFORMATION_SCHEMA.COLUMNS

[christian-schlichtherle]

Affected Version

Druid 29.0.1

Description

Running the following query

select JSON_OBJECT('name': COLUMN_NAME, 'type': DATA_TYPE)
from INFORMATION_SCHEMA.COLUMNS

produces

Error: RUNTIME_FAILURE (OPERATOR)

cannot translate call json_object($t17, $t18, $t3, $t19, $t7)

java.lang.RuntimeException

Note that the error message quotes the json_object call to receive five parameters, but maybe that's an unrelated internal detail.

For comparison, the following works (but is useless):

select JSON_OBJECT('name': 'foo', 'type': 'VARCHAR')