SF-Data-Arch Data Migration Practice Question
Exhibit
Error: UNABLE_TO_LOCK_ROW: unable to obtain exclusive access to this record or 1 records: [001xx000003GYaA, ...]
Refer to the exhibit. During a high-volume migration, the team encounters the provided error frequently. What is the most likely cause?
⚠ Common exam trap
Candidates frequently mistake locking errors for permission or data format issues, missing the core architectural problem that concurrent multi-threaded updates on shared parent records cause deadlocks.
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
✓
Multiple threads are updating child records that share the same parent account.
The 'UNABLE_TO_LOCK_ROW' error indicates that multiple threads or processes are attempting to update the same record or its parent records simultaneously. In data migration, this usually happens when records sharing the same parent are processed in parallel. By reordering the data or reducing the concurrency in the bulk load, architects can prevent these deadlocks and ensure successful completion without constant retries or system instability.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The batch size is too small, causing excessive commits to the database.
Why it's wrong here
Small batch sizes generally reduce the risk of row locking because fewer records are processed per transaction. While small batches increase the total number of transactions, they do not inherently trigger record locking issues unless the specific records being processed have high contention from other concurrent automated system tasks.
- ✓
Multiple threads are updating child records that share the same parent account.
Why this is correct
When child records are updated, Salesforce locks the parent record to ensure data integrity. If multiple threads attempt to update children of the same parent simultaneously, they compete for the parent lock, resulting in the UNABLE_TO_LOCK_ROW error. This is a classic concurrency bottleneck in multi-threaded bulk migration processes.
- ✗
The API user does not have sufficient permissions to modify the account records.
Why it's wrong here
Permissions issues typically return 'INSUFFICIENT_ACCESS_OR_READONLY' errors rather than locking exceptions. A locking error specifically points to database contention caused by parallel operations on shared resources. Insufficient permissions would fail consistently regardless of the threading model or the order in which the records are being processed during the load.
- ✗
The Salesforce database is experiencing a scheduled maintenance window.
Why it's wrong here
Scheduled maintenance windows typically render the platform unavailable or put it in read-only mode, which would cause connection failures or specific maintenance errors. Row locking is an application-level contention issue occurring during active data processing, not a result of platform-wide maintenance or service unavailability events in the infrastructure.
About these practice questions
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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.