• Standard CDS view I_BILLINGDOCUMENTITEM is delta enabled but delta load type is not showing up.
• Unable to extract the billing data to the boundary systems.

• SAP S/4HANA as the source / provider;
• SAP Datasphere as the target / subscriber;

1. Create a replication flow for the CDS view I_BILLINGDOCUMENTITEM.
2. Observe that the delta load type is not showing up despite the view being delta enabled. Only mode 'Initial Only' is visible.

The CDS view I_BillingDocumentItem contains a table function, which is not supported. This's mentioned in SAP Note 2890171 - SAP Datasphere / SAP Intelligence - ABAP Integration - SAP for Me 

"Not supported CDS Views

CDS Views making use of a table function are not supported for delta processing. Only initial load is supported in this case. "

Delta loading is not possible for such CDS views delta mechanism can't recognize behavior of function implementations.

How to check if a CDS view has table function?

1. Run /nSDDLAR and select option [x]Base Object Explorer -> Execute
2. Start Data Source Name: I_BILLINGDOCUMENTITEM -> Execute
3. Expend the node and its sub-nodes. Table function P_VBRP_SDM_PHASE_BADI_TF will be shown as below:
   

CDS view I_BILLINGDOCUMENTITEMDEX may be used as the alternative. It doesn't have table function or other AMDP. Therefore it supports Initial+Delta mode.

To import / enable CDS view I_BILLINGDOCUMENTITEMDEX, please apply SAP Note:

3591958 - Enablement of data product BillingDocument, PreliminaryBillingDocument, and BillingDocumentRequest

• Standard CDS view
• I_BILLINGDOCUMENTITEM
• Delta enabled
• Delta load type
• Data extraction
• Boundary systems