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| META TOPICPARENT |
name="SystemAdministration" |
File Analysis and Recovery
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| | Recovering a Damaged File:
There are several techniques that can recover a damaged file. It's not possible to determine in advance which technique will give the best results, therefore we recommend you back up the damaged file, then try these techniques to see which one recovers the most data |
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< | Rebuilding the key file |
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> | Important Note
The Export and Import utilities should not be used for recovering a damaged file. The export routine will stop reading the corrupt file when the corruption is encountered. The resulting export file will be missing the remaining data records.
Rebuilding the key file |
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This is the easiest & simplest type of recovery. Either delete or rename the existing .key file, then run 'Create Files' on the Data File Management menu. This will rebuild the key file, and when it is complete run the 'Verify' step again to check the record counts and confirm the file is good. Even if the file passes verification, you might have lost data. If possible, check the file to see if any valid data was lost. |
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< | Export/Import the file |
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> | Restoring files from Backup
Note that all work performed since the backup was made will be lost.
When restoring design files, the entire application should be restored from backup, not just a single file. The best course of action is to restore all of the applications for the version to ensure that design integrity is maintained across applications. |
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< | This approach might recover more data than rebuilding the key. It will read the file by it's primary key and export the data. You can then import the file with the 'Replace' option to rebuild the .dat and .key file. Import and Export are on the Data File Management menu.
APPX -recover Option |
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> | When restoring data files, it may be necessary to restore the entire database. For example, it makes no sense to restore an Order file without also restoring the line item file. Consider other files which may have been updated during the course of processing. Those files may also need to be restored.
APPX Recover Utility |
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< | If the above techniques aren't successful, then you can try the '-recover' option. You can also use this technique to recover accidentally deleted records, if you can perform this procedure in time. Since APPX re-uses deleted records, if new data is added after the deleted records, the deleted record may already be overwritten.
Usage: |
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> | If the above techniques aren't successful, then you can try the 'appx.exe -r' option. You can also use this technique to recover accidentally deleted records, if you can perform this procedure in time. Since APPX re-uses deleted records, if new data is added after the deleted records, the deleted record may already be overwritten.
Usage: |
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| In Windows: |
%APPXPATH%\..\appx.exe -r old.file new.file [deleted.record.file] |
| In Unix: |
$APPXPATH/../appx -r old.file new.file [deleted.record.file] |
This utility will read an APPX indexed data file (.dat) and copy the good/active records to the output file. Any corrupt data is hex-dumped to the screen. If you redirect standard output (>bad.data ), you can collect any corrupted data into a file, for later examination. |
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This utility does not deal with duplicate primary or unique alternate indices. |
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< | After the command is complete, new.file contains the salvaged data. To access it, rename or delete the original file, then rename the new file to the original file name. Then you must create a new *.key file. This is done by renaming or deleting the existing *.key file, then running "Create Files" on the Data or Design File Management menu. The *.key file contains pointers to all of the data records in the *.dat file. By recovering the *.dat file, you invalidate the original *.key file.
Example: |
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> | By recovering the *.dat file, you invalidate the original *.key file.
After the command is complete, new.file contains the salvaged data. To access it, rename or delete the original file, then rename the new file to the original file name. Then you must create a new *.key file. This is done by renaming or deleting the existing *.key file, then running "Create Files" on the Data or Design File Management menu. The *.key file contains pointers to all of the data records in the *.dat file.
Example: |
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The following command (in Windows) ... |
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