Source table in configuration item is not showing

[kimberlylp]

Why doesn't a table extended from configuration item show the columns that are on cmdb_ci like incident shows the task root columns?

I created u_is_this_real on cmdb_ci, but it doesn't show me that on any of the extended tables; they each show their own name respectively. However incident shows all the columns that are created on task as table = task.

[Sandeep Rajput · Accepted solution]

@kimberlylp Incident and Configuration Item tables follow different table extension models. Incident table follows, 

Table per hierarchy extension model where 

Fields are derived from parent class:- Child classes derive fields from parent classes. For example, the Incident table derives fields from the Task table.

On the other hand cmdb_ci table follows Table per partition extension model where

Fields do not derive from parent class: - Child classes do not derive fields from parent classes. Instead each child class has its own list of fields. For example, the Base Configuration Item [cmdb], Configuration Item [cmdb_ci], and Hardware [cmdb_ci_hardware] tables all have their own field definitions.

I recommend reading this documentation https://docs.servicenow.com/bundle/washingtondc-platform-administration/page/administer/table-admini... to know more about the extension models and their behaviour in ServiceNow.

Please mark the response helpful and accepted solution if it manages to address your question.

[kimberlylp]

Thank you for the information.