SOAP API Developer Guide

Introduction to SOAP API
Reference
Using the API with Salesforce Features
Implementation Considerations
Objects and SOAP API Calls and Headers for Apex
Outbound Messaging
Data Loading and Integration
Data Replication
API Calls for Data Replication
Scope of Data Replication
Data Replication Steps
Object-Specific Requirements for Data Replication
Polling for Changes
Checking for Structural Changes in the Object
Feature-Specific Considerations
Glossary
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Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Checking for Structural Changes in the Object

In the API, data replication only reflects changes made to object records. It does not determine whether changes have been made to the structure of objects (for example, fields added to—or removed from—a custom object). It is the responsibility of the client application to check whether the structure of a given object has changed since the last update. Before replicating data, client applications can call describeSObjects() on the object, and then compare the data returned in the DescribeSObjectResult with the data returned and saved from previous describeSObjects() invocations.