When an end user modifies one or more rows of data from a BOSS REST Data Source, by default the APEX engine saves all the modified rows in a single, efficient bulk operation. For example, suppose a user inserts four new rows in an interactive grid region, modifies three rows, and deletes two rows, and then clicks Save. After passing the lost update protection checks mentioned above, the APEX engine sends all nine rows in a single round trip to the BOSS REST endpoint.

If you notice the BOSS REST endpoint you are working with does not behave as expected using bulk DML, you can disable this by setting the Use Bulk DML data source setting to No. When bulk DML is disabled for a BOSS REST Data Source, each delete, insert, and update is done using a separate call to the BOSS REST endpoint. In addition, Bulk DML only works for top level business object endpoints. When using REST Data Sources for nested child resources, set Use Bulk DML to No.