The pattern: configure the External Data Source, validate the connection, sync the External Object definitions, configure relationships, surface in the UI.
- Create the External Data Source
Setup, External Data Sources, New. Pick the adapter type (OData 2.0, OData 4.0, Cross-Org, Custom). Enter the source URL and authentication. For OData, the URL is the OData service root; the platform discovers entity collections from the metadata document.
- Validate the connection and sync schema
Click Validate and Sync. Salesforce fetches the source schema and lists every entity available. Pick which entities to expose as External Objects. The platform creates External Object definitions (api names ending __x) with auto-generated field mappings.
- Configure relationships
On the External Object, add Indirect Lookup or External Lookup relationships to Salesforce objects. Indirect Lookup needs a matching field on the Salesforce side; External Lookup uses the External Object''s primary key.
- Add to page layouts and apps
Edit page layouts on the parent objects (Account, Case) to add the External Object''s related list. Build list views on the External Object itself if direct browsing matters. Add to the Lightning navigation as appropriate.
- Monitor source performance
Setup, External Data Sources, click into the source, view recent queries and response times. Slow source responses degrade the Salesforce UX; coordinate with the source-system team to ensure adequate performance.
OData 2.0, OData 4.0, Cross-Org (Salesforce-to-Salesforce), Custom Apex (DataSource.Provider interface). Pick based on source capability.
OData option that caches query results briefly to reduce source-system load. Suitable when source data does not change second-by-second.
Anonymous, Per User (each user supplies credentials), Named Principal (one set of credentials for the entire org). Match to the source security model.
Read-only or read-write. Read-write requires the source to expose write endpoints and the adapter to support DML. Reads are universal; writes are not.
- Every list view, report, or related list triggers a live source query. Slow sources make Salesforce feel slow; users blame Salesforce.
- Bulk writes are expensive. Architecture suits UI-driven one-at-a-time writes, not nightly batch loads.
- External Object reports cannot join to standard Salesforce reports natively. Use the cross-object lookup or build a Custom Report Type per case.
- Cache is limited to a few minutes via High Data Volume. For truly real-time data, every query goes through. For semi-static, the cache helps.
- Per-source licensing applies. Connecting five external sources costs more than connecting one, regardless of record volume.