Ownership, parent-child and lookup data skew
How ownership, parent-child (account) and lookup skew cause long sharing recalculations and record-lock errors, the 10,000-record guidance, where to place an unavoidable skewed owner, how to break lookup skew, and how group membership locking and granular locking affect realignments.
Given a customer scenario, recommend approaches and techniques to avoid data skew (record locking, sharing calculation issues, and excessive child to parent relationships).
~7 min read · 15 practice questions ·
What the exam expects
- Recognise ownership, parent-child and lookup skew from record counts and symptoms (long sharing recalculation, UNABLE_TO_LOCK_ROW errors).
- Place an unavoidable skewed owner: no role, or its own top-level role that never moves, outside sharing-rule source groups.
- Spread children so no parent holds more than about 10,000 records.
- Break lookup skew with picklists, blank lookups, more lookup records, shorter saves and smaller batches.
- Plan realignments around group membership locking and granular locking.
Key terms: ownership skew (one user owns more than 10,000 records of an object); parent-child skew (10,000 or more children under one parent account); lookup skew (very many records look up to one record); record lock (held on a lookup target while a record saves); granular locking (lets unrelated group operations run at the same time).
Key facts
- Detail
- One user owns more than 10,000 records of an object
- Detail
- Separate top-level role, never moved, not in sharing-rule source groups
- Detail
- Use fields that rarely change
- Detail
- 10,000 or more children under one account
- Detail
- May re-examine sharing on every child
- Detail
- Target record locked on each insert or update
- Detail
- Reduce batch size
- Detail
- Enabled by default
- Detail
- Counts as role reparenting
Sources for this section (6)
- Ownership Data Skewdeveloper.salesforce.com (opens in a new tab)
- Architect Record Ownership Skewdeveloper.salesforce.com (opens in a new tab)
- Parent-Child Data Skewdeveloper.salesforce.com (opens in a new tab)
- Avoid Account Data Skewdeveloper.salesforce.com (opens in a new tab)
- Managing Lookup Skewdeveloper.salesforce.com (opens in a new tab)
- Group Membership Lockingdeveloper.salesforce.com (opens in a new tab)
- Why does parking 200,000 contacts under one account slow sharing changes?
- When should a skewed lookup become a blank value instead of a picklist?
- Why does changing a large partner account's owner block other admins' role changes?
- What three things should a skewed owner that needs a role avoid?
The questions are free to read. Answers with their sources and self-grading are included with the pack.
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