What is the MOST effective method for verifying the correctness of individual account balances after a database migration?

The most effective method for verifying the correctness of individual account balances after a database migration is to perform sample testing of the migrated account balances. This approach allows for a direct examination of specific records to ensure they have been accurately transferred. By selecting a sample of account balances, one can validate the correctness of the information through substantive testing, which involves checking the actual numerical values and their computations.

This method is particularly effective because it enables auditors to identify potential discrepancies and errors in individual account balances, ensuring that each account is accurately represented in the new database. Additionally, sample testing can reveal systematic issues that may not be evident through other methods, thus providing a higher degree of confidence in the overall accuracy of the migration.

While comparing hash totals, verifying the number of records, and comparing control totals can provide useful checks, they generally focus on overall data integrity rather than on the accuracy of specific account details. Hash totals and control totals can identify discrepancies in data volume or integrity but may miss errors within the actual account balances. Verifying the number of records only ensures that the same amount of data exists post-migration without confirming that the data is correct. Therefore, sample testing is the most comprehensive and effective way to ensure accuracy after migration.