Maintaining database integrity
One of the most important responsibilities of a database
administrator is to maintain the integrity of the database and prevent it from
Derby must be able to sync
to disk. Some machine, disk, or operating system settings can prevent a proper
sync and cause unrecoverable database corruption in the event of a power
failure, system crash, or software crash. To avoid database corruption, you can
do the following:
- Do not enable disk write caching on the hard drive that holds the database.
Disable write caching if it is turned on (it is enabled by default on many
Windows systems). Disk write caching can increase operating system performance.
However, it can also result in the loss of information if a power failure,
equipment failure, or software failure occurs. Consult your operating system
support documentation for information on how to disable disk write caching.
- Run Derby on a local
drive rather than on an NFS mounted, SMB mounted, or other network mounted
- Disable any other settings or options that might prevent a proper sync to
disk when Derby is writing
its transaction logs or other data.
Many corruption issues can arise from improper backups or restores. Back up
your database in a way that prevents it from becoming corrupted:
- Always make sure the database is shut down or frozen before using operating
system commands to back it up.
- Always back up the database to a fresh location rather than overwriting
any existing data.
After you perform a backup, check the consistency of the database. See
Checking database consistency for details.
See Backing up and restoring databases for more