Data correction in book-keeping is simple, even for previous accounting periods. Hence, for example, a mis-posting to a supplier account is easily corrected, a nominal account may be changed or a VAT amount amended.
Any change made to a posting is automatically reflected in the nominal ledger. It is impossible to post a sales/purchase ledger transaction without the effect being shown in the nominal ledger: so no more inconsistent or corrupt databases.
Data entry to batches allows checking of entries in the batch before they affect the various ledgers. Hence, changes at this stage are straightforward. After the batch has been posted to the ledger, it is still possible to change entries, but the process is then deliberately more difficult and only possible if you have the requisite permission.