# Survivorship rules for winning attribute values

*Platform Data Architect Study Guide · Master Data Management · Last updated October 26, 2026 · https://www.certifyforce.com/study-guide/platform-data-architect/master-data-management/survivorship-rules-for-winning-attribute-values*

How to pick the value that survives when sources disagree: trust, recency, completeness and frequency as criteria, Data 360 reconciliation rules (Source Priority, Most Frequent, Last Updated, Ignore Empty Values, object defaults and field overrides, tie-breakers), and what a Salesforce merge decides for you through the principal record.

- Certification: Salesforce Platform Data Architect
- Exam section: Master Data Management
- Study guide: https://www.certifyforce.com/study-guide/platform-data-architect

**Official exam objective:**

> Given a customer scenario, recommend approaches and techniques for consolidating data attributes from multiple sources. Discuss criteria and methodology for picking the winning attributes.

## What the exam expects

- Pick the survivorship criterion (source trust, recency, completeness, frequency) that fits each attribute, and explain thresholds and weights as a methodology.
- Configure Data 360 reconciliation rules: Source Priority, Most Frequent, Last Updated, Ignore Empty Values, object defaults and field overrides, and their tie-breakers.
- State what reconciliation does not do: change sources, reconcile contact points or pick a value for every application.
- Choose the principal record in a Salesforce merge for the values users can't pick.

Key terms: **survivorship** (rules that decide which source value a consolidated record keeps); **reconciliation rule** (the Data 360 rule that picks one value for a single-value unified field); **Source Priority** (ranks data lake objects from most to least preferred); **Ignore Empty Values** (skips nulls when picking); **principal record** (the merge survivor whose hidden and read-only values are kept).

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Rule scope | Object-level default, overridable per field | [Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5) |
| Last Updated | Needs Last Modified Date mapped; ties alphabetical | [Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5) |
| Most Frequent tie | Last updated value wins | [Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5) |
| Source Priority, same source twice | Last updated value wins | [Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5) |
| Ignore Empty Values | Nulls never selected | [Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5) |
| Source systems | Never updated by reconciliation | [Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5) |
| Contact points | Not reconciled; all stay on the profile | [Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5) |
| Merge audit fields | Created By and Created Date from the oldest record | [Merge Considerations](https://help.salesforce.com/s/articleView?id=sales.account_merge_considerations.htm&language=en_US&type=5) |
| Site users | Account with site users must be principal to keep them | [Merge Considerations](https://help.salesforce.com/s/articleView?id=sales.account_merge_considerations.htm&language=en_US&type=5) |

## Check yourself

- When is Last Updated not available as a reconciliation rule?
- When does a Source Priority field rule fall back to recency?
- Why does choosing the principal still matter if users pick field values during a merge?
- What does Ignore Empty Values change for Source Priority?

## Sources

- [Identity Resolution Reconciliation Rules](https://help.salesforce.com/s/articleView?language=en_US&id=sf.c360_a_reconciliation_rules.htm&type=5)
- [Understand Unified Profiles and Their Impacts on Data Strategy](https://trailhead.salesforce.com/content/learn/modules/data-and-identity-in-salesforce-cdp/get-to-know-unified-profiles)
- [Considerations for Merging Duplicate Accounts](https://help.salesforce.com/s/articleView?id=sales.account_merge_considerations.htm&language=en_US&type=5)
- [Merge Duplicate Accounts in Lightning Experience](https://help.salesforce.com/s/articleView?language=en_US&id=sales.account_merge_lex.htm&type=5)
- [Identity Resolution Match Methods](https://help.salesforce.com/s/articleView?language=en_US&id=data.c360_a_match_rules_criteria_fuzzy_normalized.htm&type=5)
- [Discover Master Data Management Capabilities](https://trailhead.salesforce.com/content/learn/modules/informatica-cloud-master-data-management-basics/discover-master-data-management-capabilities)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 6 linked practice questions, and unlimited timed mock exams are included with the Platform Data Architect pack (USD $19): https://www.certifyforce.com/practice-exams