We use Dictionary override to allow a field in a child table to have a different value or behavior than the same field in a parent table.
In your case you want to change the data type entirely from string to choice which is not possible in OOTB configuration.
As you can see here, there is no option to achieve as per the existing configuration.
Even if you somehow try to change by any means via HI support or enhancement request, the next time instance upgrade happens, the updates will skip and may affect in your instance health scorecard.
Best way to create a new field and hide this existing field on child table via ACL or any UI policy.
I had faced this issue in CMDB and had same solution for that.
Please mark my answer as correct if its helpful to you.
We use Dictionary override to allow a field in a child table to have a different value or behavior than the same field in a parent table.
In your case you want to change the data type entirely from string to choice which is not possible in OOTB configuration.
As you can see here, there is no option to achieve as per the existing configuration.
Even if you somehow try to change by any means via HI support or enhancement request, the next time instance upgrade happens, the updates will skip and may affect in your instance health scorecard.
Best way to create a new field and hide this existing field on child table via ACL or any UI policy.
I had faced this issue in CMDB and had same solution for that.
Please mark my answer as correct if its helpful to you.
