Creating Alternative Keys

1. Start T-code: BOBF (BOPF: Business Object Configuration). Select your Business Object.
2. Create Secondary Indexes for the ROOT database table. 
3. Double click the table. Change to edit mode and click Indexes and create Indexes. Provide the Index name Eg: A1.
4. Provide with the Index fields. Save and activate. Also Activate the Table. 
5. Type DEBUG in the T-code. Confirm the POPUP box as Yes. Click on Change mode button. Since for creating Alternate keys the option is disabled. 
6. Provide with the details as below and Save: 
7. I have created a structure for TRQ ID and assigned to Table type. 
8. Double click combined table type in ROOT. 
9. Select Secondary Key Tab. Select Key component as TRQ_ID from F4 help and Key Access as Non-Unique Sorted. Save and activate.
10. Regenerate the Constant Interface from Extras.
11. Testing the Alternative Keys:
    Open T-code BOBT (Business Object Builder – Test). Provide with your Business Object name. Here we can pass the Alternative Key. Eg: 1001. You get the corresponding record.