SF-Data-Arch Data Migration Practice Question
A Salesforce data architect is preparing to migrate 5 million Account records from a legacy CRM. The legacy system has a field 'Legacy_Owner__c' that contains the email address of the account owner. During migration, the architect must ensure that the ownership is assigned to the correct active Salesforce User. Which approach should be used to map the legacy owner email to the Salesforce User ID?
⚠ Common exam trap
The trap here is assuming that Salesforce can automatically resolve email addresses to User IDs during a data load without an explicit mapping step.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Create a custom field on Account to store the legacy owner email, then use a post-load process or Data Loader to update OwnerId based on a User lookup.
To map legacy owner emails to Salesforce User IDs, the architect should first load Accounts with the legacy email stored in a custom field. Then, using a lookup or ETL transformation, the correct User IDs can be determined and applied to the OwnerId field. This two-step process avoids errors and ensures accurate ownership assignment.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Load the email addresses into the OwnerId field directly; Salesforce will automatically resolve them to User IDs.
Why it's wrong here
Salesforce does not automatically resolve email addresses to User IDs when loading into the OwnerId field. The OwnerId field expects a valid 15- or 18-character Salesforce User ID. Attempting to load email addresses will result in 'Invalid ID' errors or records assigned to unintended users. A separate mapping or lookup step is required to convert emails to User IDs before the load.
- ✗
Use the Data Loader's 'Bulk API' with the 'Assignment Rule' option enabled to automatically assign owners based on email.
Why it's wrong here
The Bulk API does not have an 'Assignment Rule' option that maps email addresses to User IDs. Assignment rules operate on case or lead records and use predefined criteria, not email-to-user resolution. Enabling assignment rules during a bulk load can also trigger unintended ownership changes or queue assignments. This option misrepresents both the API capabilities and the assignment rule functionality.
- ✓
Create a custom field on Account to store the legacy owner email, then use a post-load process or Data Loader to update OwnerId based on a User lookup.
Why this is correct
This approach correctly separates the migration of Account data from the ownership assignment. Storing the legacy email in a custom field preserves the original data for audit, and a subsequent update using a User lookup (via ETL, Data Loader, or Apex) can accurately set OwnerId. This avoids load failures and ensures ownership is assigned to the correct active User. It also allows validation of email-to-user mappings before final assignment.
- ✗
Load the legacy owner email into the Account Owner field using the 'External ID' feature of the User object.
Why it's wrong here
The User object does not support using an External ID to directly populate the OwnerId field during a load. While User records can have an External ID field, the OwnerId field on Account expects a direct reference to a User ID. Without a pre-established lookup, the load will fail. A separate mapping step is required to resolve emails to User IDs before populating OwnerId.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Salesforce exam blueprint
This SF-Data-Arch practice question is part of Courseiva's free Salesforce certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SF-Data-Arch exam.