What is the difference between a lookup relationship and a master-detail relationship in Salesforce?
Theme: Data Modeling Role: Salesforce Administrator Function: Sales
Interview Question for Salesforce Administrator: See sample answers, motivations & red flags for this common interview question. About Salesforce Administrator: Manages and maintains the Salesforce CRM system for the sales team. This role falls within the Sales function of a firm. See other interview questions & further information for this role here
Sample Answer
Example response for question delving into Data Modeling with the key points that need to be covered in an effective response. Customize this to your own experience with concrete examples and evidence
- Definition: A lookup relationship is a relationship between two objects where one object has a field that references another object's record. A master-detail relationship is a relationship between two objects where the detail object is considered a child and the master object is considered a parent
- Ownership & Deletion: In a lookup relationship, the child object does not have an ownership relationship with the parent object. Deleting a parent record does not automatically delete the child records. In a master-detail relationship, the child object is owned by the parent object. Deleting a parent record automatically deletes the child records
- Access & Security: In a lookup relationship, the child object does not inherit the sharing and security settings of the parent object. Each object has its own sharing and security settings. In a master-detail relationship, the child object inherits the sharing and security settings of the parent object
- Roll-Up Summary Fields: In a lookup relationship, roll-up summary fields cannot be created on the child object. In a master-detail relationship, roll-up summary fields can be created on the parent object to calculate and display aggregated values from the child records
- Cascade Delete: In a lookup relationship, deleting a parent record does not automatically delete the child records. In a master-detail relationship, deleting a parent record automatically deletes the child records
- Record Ownership: In a lookup relationship, the child records can have different owners than the parent record. In a master-detail relationship, the child records always have the same owner as the parent record
- Sharing & Visibility: In a lookup relationship, the child records do not inherit the sharing and visibility settings of the parent record. In a master-detail relationship, the child records inherit the sharing and visibility settings of the parent record
- Required Fields: In a lookup relationship, the child object can have required fields that are not required on the parent object. In a master-detail relationship, if a field is required on the parent object, it is also required on the child object
- Dependent Picklists: In a lookup relationship, dependent picklists can be created on the child object. In a master-detail relationship, dependent picklists cannot be created on the child object
- Cross-Object Formula Fields: In a lookup relationship, cross-object formula fields can be created on the child object to reference fields on the parent object. In a master-detail relationship, cross-object formula fields are not available on the child object
Underlying Motivations
What the Interviewer is trying to find out about you and your experiences through this question
- Technical knowledge: Assessing your understanding of Salesforce data relationships
- Experience: Evaluating your hands-on experience with Salesforce administration
- Problem-solving skills: Testing your ability to determine the appropriate relationship type based on business requirements
- Attention to detail: Checking if you understand the nuances and implications of different relationship types
Potential Minefields
How to avoid some common minefields when answering this question in order to not raise any red flags
- Confusing or incorrect definitions: Providing incorrect or unclear definitions of lookup and master-detail relationships
- Lack of understanding of relationship behavior: Not being able to explain the behavior of lookup and master-detail relationships, such as cascading deletes or record ownership
- Inability to differentiate use cases: Not being able to articulate the specific scenarios where lookup relationships are more suitable than master-detail relationships, and vice versa
- Limited knowledge of Salesforce features: Not being aware of additional features and limitations associated with lookup and master-detail relationships, such as roll-up summary fields or sharing settings
- Failure to mention data integrity: Neglecting to highlight the importance of maintaining data integrity and how lookup and master-detail relationships contribute to it