Delta extraction from FI module in R/3

Hello,

Could you please tell me how the delta records are updated in BI in the case of extraction from FI? I understand that RSA7 is not updated with the delta records as in the case of LO extraction. How can the delta records be validated on the BI side? BWFI_TIMEST and BWFI_AEDAT would only give the time stamps of change in documents. Can RSA3 be used to validate the records? Please help!!

Thank you.