Salesforce allows the creation and manipulation of fields within Salesforce to manage integrations with other systems. These fields are marked as External Id fields within Salesforce. An external id contains unique information that Salesforce can use to identity specific records that are linked to records within other systems.
The advantage of creating and maintaining external ids with using SmartConnect are as follows:
|•||When creating new records, if an external id is defined the system will check that the record does not already exist before creating the new record.|
|•||When updating records the system has a unique field it can check to determine if the record exists. If no unique record exists then the key fields on the map are used to determine the records to update. This may not be as accurate as using an external id as multiple records may be returned when selecting by map key fields, and in that instance all returned records would be updated.|
|•||When performing updates, if the update entity contains an external id, only the external id is required for the update. If no external id is provided a query on the data must be performed to get the matching entity id(s), upon which the updates will occur. Update proceed quicker if an external id has been defined.|
More information on External ID's and how to set them up within Salesforce can be found here.