Data Management — Import, Export & Duplicates
Data Import Wizard vs Data Loader, upsert with external IDs, duplicate and matching rules, backups.
Admin 2 min readData LoaderImportDuplicatesUpsert
Import Wizard vs Data Loader
| Data Import Wizard | Data Loader | |
|---|---|---|
| Where | In the browser (Setup) | Desktop app / command line |
| Volume | Up to 50,000 records | Up to 5 million |
| Objects | Common standard objects + custom objects | All objects that support the API |
| Delete / export | ❌ | ✅ insert, update, upsert, delete, hard delete, export |
| Scheduling | ❌ | ✅ (command line) |
| Duplicate prevention | Built-in matching for some objects | Use upsert / duplicate rules |
Upsert with an External ID
Upsert = insert or update based on a matching key.
csv
ERP_Id__c,Name,Industry
ERP-1001,Acme Corp,Technology
ERP-1002,Globex,Energy
Map ERP_Id__c (External ID) as the match field → existing records update, new ones are created. You can also link parents by their external ID (e.g. Contact Account:ERP_Id__c), so you never need Salesforce Ids in the file.
Load order and tips
- Load parents before children (Accounts → Contacts → Opportunities).
- Turn off or bypass noisy automation / validation for one-time migrations (and turn it back on).
- Keep Ids and error files from each load.
- Test in a sandbox first.
- Mind the batch size: smaller batches if triggers hit limits.
Duplicate management
- Matching rule — how records are compared (exact / fuzzy on name, email, phone…).
- Duplicate rule — what happens: Allow (with alert/report) or Block, on create and/or edit.
- Duplicate rules also run for API and Apex saves (unless allowed with headers /
DMLOptions). - Use Merge on Accounts, Contacts and Leads to combine duplicates.
Backups & recycle bin
- Deleted records stay in the Recycle Bin for 15 days.
- Data Export (weekly/monthly) or Backup & Restore for real backups.
- Hard delete (Data Loader) skips the recycle bin.
Interview questions
- You need to load 200,000 contacts linked to accounts from an ERP — how? → Data Loader upsert with external IDs, parents first.
- Matching rule vs duplicate rule?
- How long do deleted records stay in the recycle bin? → 15 days.