With large volumes of data comes the risk of file corruption, and sadly it’s unavoidable. The best long term step you can take is to develop a process which works effectively while limiting risk. Data migration tools offer a reliable way to recover work from even a damaged file, while potentially resolving further data corruption down the line.

With Excel’s great tools and functionality but clear limitations, it’s no surprise to see errors eventually occuring. When you face file damage, you’ll normally have two options to recover corrupted files – either recovering the file to continue using it as best you can, or reverting to a last known backup, where save progress may have been lost.

Our FileMaker developer experts suggest going with the first option because it is the best and fastest way to get the program running. However, it is not a recommended option for all users as there is no guarantee that recovering the corrupted file will remove the underlying corruption at source. You might correct the problem enough to open the file, but leave the root cause of the problem in place, which could lead to further corruption or other issues later. You may even end up removing elements like layout objects or record data in a desperate attempt to recover your file.

Reverting your files to the most recent backup just before a crash seems like a good option too, but you may avoid choosing this option as it includes loss to data and functionality. What does this really mean, and how can you avoid it?

Data Loss

To prevent data loss, import all records for all tables into a clone of the backup. Even if you already had a script in place that cloned the files, running the script could take a long time. However, with the help of a data migration tool, this import process becomes much faster.

Functionality Loss

To report a functionality loss, you need to re-deploy all changes made since the backup file was created. You would have to manually recreate those changes. If you keep tracking your changes over time, it’s possible to reduce this loss but it may involve significant effort. Avoiding tracking these changes might lead to a bigger problem as identifying the difference between the files will become difficult. In such a situation, you could opt to use third-party software which enables a side-by-side comparison of two versions of the same file.

First Steps

If you are dealing with a file that failed a consistency check and wouldn’t reopen, then our top level tool will help you recover that file. Try reverting to the last known, good backup and then restore the data using the new data migration tool. You can do this by specifying a source file and a target file. If the source file is damaged, then target the clone of the backup file. You can set hourly, daily, and weekly backup schedules for these files.

Will a Data Migration Tool Remove Corrupt Record Data?

FileMaker’s Data Migration Tool can help recover a corrupt file; but can it also remove corrupt record data? The answer in most cases is yes, but to check this on your own file, you can try out the tool if you report a symptom…

To begin, try searching for (for example) status “X” and location “Y” shows 20 records. You will see that three of these records don’t display any value. If you delete these three records, FileMaker Pro will not report an error. However, the total record count doesn’t change, even when you repeat the search.

These symptoms could be a warning sign of corrupt record data or corrupt field indexes. 

While the data migration tool may not remove bad record data, you can try the following methods to restore your file…

• Rebuild field indexes – Question marks can sometimes indicate damaged field indexes. You can manually rebuild each field index in the affected table, or you can run ‘Recover’ on the file without actually doing a recovery. Simply select the option to rebuild field indexes. Select the “copy file blocks as-is” and “rebuild field indexes now” options and leave all of the other options unselected.
• Reimport data – Arrange the found set to include all records and exclude the corrupt ones. Export the found set using the merge format and write a script to shorten the table. Now import the good data back into the file and import the corrupted records from a backup, if you can find a backup that still has those records non-corrupted.

Recovering Corrupted Files and Best Practices

In addition to being used as a deployment tool, the FileMaker Data Migration Tool can also be used to recover the corrupted file by moving production data into a clone of a last known good backup. This tool makes the recovery smooth and quick, and makes it an essential part of your process.

Make a habit of simple best practices before a problem occurs, including setting up backup schedules to create clones of your database files, maintaining a reasonably long history of backups and clones, enabling verification for your weekly or daily backup schedules, and enabling email notifications so that you will be informed if a file becomes damaged. Keep a check on the changes you deploy to production.

If you are unable to open the database, copy or move the damaged file to another folder. Recover the file and decide on which clone you will use. Go as far back in time as you can without skipping on any development changes that you may have made to the file. When using a data migration tool, specify the recovered damaged file as the source and the clone as the target. If the tool gives an error, open and then close the recovered file, and then try running the tool again.

The Best FileMaker File Solution

To mitigate errors and benefit from your own bespoke solution, tailored to the unique demands of your business, our team of certified FileMaker professionals are ready to help your company with a custom-made workflow system for all your needs. This will greatly help you organize your projects and eliminate the risk of file errors before they even occur. Connect with us today to find out more.