APPX Software Library

Chapter 7: Analysis and recovery

Physical recovery

A healthy encrypted file is decrypted with the export and Replace procedure in Chapters 4 and 6. Physical recovery is for a damaged file. Restore a verified backup when that is the appropriate way to recover the database.

Choose the recovery route from the file's actual condition.

ConditionAction
Encryption mismatch or FI_CRYPTRestore the correct configuration before changing files or keys
Missing or damaged index, with a readable datafileFollow Decide whether to rebuild a missing or damaged index
APPX can export every required recordPreserve and check the complete export; recreate the file with Replace under the intended encryption settings
Damaged encrypted APPX 6.2.1 fileUse a compatible 6.2.1 engine on working copies, then rebuild and verify as described below

Use an APPX 6.2.1 engine with the matching file format, structures, administration configuration, and encryption settings. Do not use a different release's engine as a shortcut for recovering an older physical file.

In the APPX 6.2.1 recovery test, nine active records survived recovery and an index rebuild after a record was deleted. Their complete exported values matched the export made before recovery. The check included a NATIONAL field and its index. Separate copies with a damaged or truncated final record each recovered the other eight records with unchanged values and reported the lost record as an error. A record that cannot be recovered still requires a backup or other trusted source.

  1. Stop all access. Preserve the original datafile, index, structure, administration backup, and key records.
  2. Work in a separate restricted directory. Choose a new output filename that does not already exist. Never use the source filename as the destination.
  3. Run the recovery utility and retain its entire log. The following Unix example uses the example paths described in the previous topic.
/opt/appx/appx -recover /srv/appx-recovery/PROSPECT.dat /srv/appx-recovery/PROSPECT-new.dat

For Windows PowerShell, substitute your own paths:

& 'C:\APPX\appx.exe' -recover 'C:\APPX-Recovery\PROSPECT.dat' 'C:\APPX-Recovery\PROSPECT-new.dat'
  1. Review the number of active records copied, deleted records removed, and errors found. Investigate skipped or damaged regions; a completed run alone does not establish that all required data was recovered.
  2. In a separate test database with matching structures and encryption settings, put the recovered .dat under the expected file name. Preserve the old index separately.
  3. Select only that test file in Data File Management and run Rebuild key Files. The recovered datafile requires a new matching index. Do not reuse the original .key file.
  1. Run Verify Integrity of APPXIO Files. Compare counts and application values, and compare a normal APPX export with a known-good export when available.
  2. Accept a recovered file only after the data and application checks are satisfactory. Plan any replacement of live data as a separate controlled restoration.

Do not use the recovery utility's -c option as a decryption or CSV-export shortcut. Keep deleted-record outputs, dumps, and recovery logs restricted. They may contain sensitive information.