Database Restoration

This procedure first replaces the database by a backup copy (produced earlier from the ORG menu) and then updates it using the current LOG file. This makes sure that it is always possible to recreate the most recent stable state of the database after a severe crash or other events that result in instability or even non-usability.
If the state of corruption is so severe that a99 cannot even start:
IF you had done a backup copy at some point, it doesn't look too bad for you.
Open a DOS window, and change to the data directory. You will find a file  xyzREST.BAT  there (with xyz  being the name of your database; cat being the standard). Just start this to get the restoration work going.
The system needs to know where the backup copy had been stored. Normally it will be a directory the name of which is specified in the INI command  DbBack=... . This name results from the last backup activity (from the ORG menu) because the name used will be recorded in the DbBack variable. This command may be changed manually, however, if circumstances require it. The `Handbook` tells more about backup/restore functions.
A restoration can be done only while no one is logged in. This will therefore be checked first. In the positive case, a99 aborts itself, i.e. the window disappears. A DOS window opens instead and displays messages from the program UPDATE which is used to do the job. After completion, a99 is automatically restarted and presents you with the restored database.

If you want to know even more
The backup copy has to be placed on a different directory. The ORG menu function makes sure that this is the case. If a backup copy had been made by other methods, like compression or tape copy, the copy must be placed on an accessible directory first. Then, restoration can begin.
Attention: It the LOG file had been copied, unnecessarily!, together with the database, you have to make sure it will not be copied back tp the data path. For there it would overwrite the current LOG file - which contains exactly those records that had been entered or changed after the backup had been made...
If the backup copy is NOT brought back to the data directory but another one, and restoration is then initiated by this method, nothing can go wrong. Only with very large databases reasons of time and space will probably force the administrator to restore the backup copy directly from the tape to the data path. Then, make sure the current LOG file is not overwritten.

?Handbook=h ac0-7