Introduction to Bulk API 2.0 and Bulk API
Any data operation that includes more than 2,000 records is a good candidate for Bulk API 2.0 to successfully prepare, execute, and manage an asynchronous workflow that uses the Bulk framework. Jobs with fewer than 2,000 records should involve “bulkified” synchronous calls in REST (for example, Composite) or SOAP.
Using Bulk API 2.0 or Bulk API requires basic familiarity with software development, web services, and the Salesforce user interface. Because both Bulk APIs are asynchronous, Salesforce doesn’t guarantee a service level agreement.