We have few json data are stored on string data type (SYNTAX 220.127.116.11.4.1.1418.104.22.168.15) field on DJ 3.5. Could it possible to change the data type of those fields to json datatype (SYNTAX 22.214.171.124.4.1.14126.96.36.199.5)?
The syntax 188.8.131.52.4.1.14184.108.40.206.5 is Binary, and not related to JSON datatypes.
Changing the syntax for an existing attribute is possible but not recommended.
There could be side effects such as requiring to rebuild indexes if there are any index, but also possibly the inability to delete specific values (if they are not fully compliant with the JSON syntax).