While FairCom always attempts to maintain backward compatibility whenever possible, transaction logs from earlier versions are generally not always compatible with newer FairCom Server formats.
Note: Unless otherwise mentioned in the version-specific Update Guides, existing data and index files are usually not affected by transaction log changes.
Removing Transaction Logs and Upgrading the FairCom Database Engine
The FairCom process makes it easy to upgrade the FairCom server using your existing files, as long as you remove prior transaction logs in a safe manner. The steps shown below are appropriate any time you are upgrading. Notice that you will shut down your server two times during this process (steps 2 and 5) to allow all files to be brought to a consistent state.
Remember that the Administrator user ID is "admin" (case insensitive) and the default password is "ADMIN" (case sensitive). The default c-tree Server name is "FAIRCOMS".
Note: We do not recommend removing FAIRCOM.FCS unless specifically instructed to do so in the notes accompanying the new FairCom version.
Several other types of log dependencies should be considered before deleting transaction logs:
2. Deferred indexes
3. Record update callbacks
If these options are in use, ensure they have processed all the log data before the logs are deleted. Otherwise the dependent data could be out-of-sync. (2 & 3 don't always use the transaction logs)
Note: Client compatibility can prevent connections to the new FairCom Database Engine. It is always advised to use the most recent matching client version with your FairCom server version.
FairCom has added logic to notify you when transaction logs may be incompatible. Please review the section "Detection of Transaction Log Incompatibilities" in the FairCom Server Administrator’s Guide for details.