Recovering Damaged Files

Power failures, hardware problems, or other factors can damage a YuleLog™ file. YuleLog provides two built-in mechanisms for restoring damaged databases: AutoRepair and Recover. AutoRepair occurs when the file is opened. Recover is a command you choose by opening YuleLog in a special way.

When the program discovers a damaged file, a dialog box will appear and tell you the name of the damaged file. Once you know which file is damaged, you can recover it.

To recover a damaged file on a Macintosh, double-click the YuleLog icon and then press Option-Command while the file is opening. On Windows, double-click the YuleLog icon and press Ctrl+Shift while the file is opening. Hold the keys down until you see the Recover File dialog box. Select the damaged file from the files in the YuleLog™ folder:

When a Recover is completed, a status dialog is displayed showing what was done to the database during recovery. The dialog box shows:

- the number of bytes copied from the damaged database into the new database

- the number of records that had to be skipped (deleted) from the recovered database

- the number of field values that had to be skipped (deleted) from the database

- the number of field definitions that had to be recreated

A newly recovered database will take longer to open than a database that was closed properly the last time it was used. This happens only the first time a recovered database is opened and is the result of rebuilding various internal structures that were deleted during recovery.

The most frequent cause of file damage occurs when YuleLog is not closed properly. Another cause of problems with YuleLog databases is media failures (for example, hard disks), where a file cannot be read by the file system.

Improperly closed files can occasionally cause damaged files.

A file is not closed properly when YuleLog is running and then:

- External power is interrupted, shutting down the computer abruptly

- YuleLog runs into a problem and presents a dialog that requires the user to quit the application (e.g., disk-read error or file-damaged error)

- Another application (or the system software) crashes, causing YuleLog to crash

- YuleLog freezes, forcing a manual restart of the computer

- A manual restart is made for some other reason

Note In all of these cases, not only is the active file damaged by being improperly closed, but so are all unlocked local files that may have been open at the same time.

AutoRepair is run automatically, if necessary, when the database is opened. On the other hand, Recover is a command you can use should the database require more extensive repairs.

The underlying action of AutoRepair and Recover is to preserve as much of the data as possible. In this context, data generically refers to records, layouts, scripts, and field definitions. Non-essential data, such as the sort order, is not recovered.

These utilities do not guarantee that the file has been completely repaired. Therefore, after managing to get a damaged database to open, you should take precautions, such as immediately saving a backup copy of the recovered database.

As a general rule, after a repaired or recovered database has been successfully opened, the file should be checked for consistent content. This is especially true if there was an active operation under way at the time of the shutdown.

If YuleLog is not able to recover a file using the above methods contact Todd Ray at YuleLog Software .