Which Records Are Copied When You Refresh a Salesforce Partial Data Sandbox

Partial Data sandbox copy works by collecting a sample of up to 10,000 records per object. Unless objects are related by a Master-Detail relationship or Required Lookup, the sampling application does not guarantee related records are included.

How Object Relationships Affect Record Sampling

For example, if there are objects A, B, C, and D with the following relationships:

• A is the parent of B via Master-Detail
• A is the parent of C via Required Lookup
• A, B, and C are parents of D via standard Lookup

The sampler picks up to 10,000 related records for A, B, and C (enforced relationships). However, the 10,000 records from D may not have A, B, or C values populated because D is treated as a top-level "parent" object due to its Lookup-only relationships. If D had a Master-Detail or Required Lookup, it would be treated as a child object and its records would be dependent on its parent's sample.

Behavior for Contacts, Accounts, and Opportunities

Contact and Opportunity records do not have a required Master-Detail relationship with the Account object. However, the Partial Copy sandbox sampling application treats the UI-enforced relationship as required:

• Contacts or Opportunities created via Apex or API without an associated Account are skipped during sampling and are not copied to the sandbox.

Storage Limitation

There is a storage limit of 5 GB for Partial Data sandboxes. If there are a large number of objects with more than 10,000 records each, the number of records copied per object may be reduced to stay within this limit.