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Tech Tip: Warnings before doing Recover by record headers
PRODUCT: 4D | VERSION: 20 | PLATFORM: Mac & Win
Published On: August 5, 2024

It is recommended to only do this option after restoring from backup or a standard repair proves ineffective, and the data file is severely damaged. if only indexes and records are damaged, then a standard repair should be enough to fix it.

Recovery by record headers has the MSC using the marker in the header of each record and compares it to a summary of that record to reconstruct it. It does not guarantee that anything relational to the recovered record is restored as well. Therefore, there may be some issues with the data file after recovery if the following is not checked beforehand.

Within the properties of the affected table, if the attribute "Records definitely deleted" were unselected, then doing a recovery by header files may cause the deleted records to disappear. The recovery option also does not take integrity constraints into account, such as duplicated values with unique fields are NULL values with unique fields with the "Never Null" option toggled.

It is extremely important to do a manual check of the data after this type of recovery to ensure that any following processes are run smoothly and the next verify on the data file does not run into any errors.