External Objects and Salesforce Connect (Overview)
By the end of this lesson, you'll be able to:
- Explain what an external object is at a conceptual level
- Distinguish an external object from Module 36's callout-based integration approach
- Recognize when real-time federated access is preferable to syncing data in
Prerequisites: "Platform Cache"
Two different integration philosophies
Module 36 and Module 42's ledger integration made explicit HTTP callouts at specific moments (a Queueable job firing after a transaction) — data flows one direction, at a chosen time, and Salesforce keeps its own copy. External objects flip this: Salesforce Connect queries the external ledger system live, every time, and Salesforce never stores a copy of that data at all.
What this looks like conceptually
Ledger_Transaction__x (an external object, not a standard/custom object)
↕ (Salesforce Connect, live query, no local copy)
External Ledger System's own databaseA SOQL query against Ledger_Transaction__x looks almost identical to querying a normal object, but under the hood, Salesforce Connect is making a live request to the external system for that query, every single time — nothing is ever stored locally.
When federated access beats syncing
If the external ledger system is the single source of truth and its data changes constantly, syncing a copy into Salesforce (Module 36's approach) risks staleness — exactly the problem Lesson 2's Platform Cache lesson warned against for Balance__c. An external object avoids staleness entirely by never storing a copy, at the cost of depending on the external system's availability and response time for every single query.
Exercise
As a comment, explain the core difference between how Module 36's Queueable callout integration and an external object each keep Salesforce data in sync with an external system.
Show hint
Think about when the data transfer happens and whether Salesforce keeps a copy.
External Objects and Salesforce Connect (Overview) Quiz
My Notes
Log in to keep private notes on this lesson.
Questions about this lesson
No questions yet — be the first to ask.
Log in to ask a question about this lesson.
Summary
An external object lets Salesforce query data that physically lives in another system in real time, via Salesforce Connect, without copying that data into Salesforce at all — a fundamentally different integration approach from Module 36's callouts.