Salesforce Data Schema (SFD)
Every object that is downloaded to SQL from Salesforce will have three tables in the Salesforce Data Schema. For example the Account object will have the tables:
After running a download the sfd_Account table will be a copy of all the data in the Account object. If the object is being downloaded with the incremental integration method the sfd_Account_history table will contain all versions of all Account records that have been downloaded. The sfd_Account_temp table is only used during the download process and can be ignored. It will normally contain the last set of downloaded data for the object.