The Content Manager OnDemand database includes recovery logs which are used to
recover from application or system errors. In combination with database
backups, they are used to recover the consistency of the database
right up to the point in time when an error occurs. Some logs, called active or primary logs,
contain transactions which have not been committed to the database.
These logs are stored in the primary database log path. Other logs,
called archived or secondary logs,
contain transactions which have been committed to the database. These
logs are stored in the secondary database log path. Both types of
logs can be used with database backups to enable forward recovery
of the database to any point in time before a failure.
When you load a report into
Content Manager OnDemand, the database manager records
changes made to the database in a recovery log:
- If you are using DB2®, when a log fills, the database
manager closes the full log and opens a new log. When all changes
to the database have been made, the database manager closes the last
log. After the load process disconnects from the database, Content Manager OnDemand copies
the closed logs from the primary database log path to the secondary
database log path. When you create a full backup image of the database
with the arsdb command, Content Manager OnDemand deletes all of the logs from the secondary
database log path. (When you create a full backup image of the database,
it invalidates the secondary logs that were created before the time
that the backup was taken.)
- If you are using SQL Server, when a log file fills, the database
manager closes the full log file and opens a new log file, provided
that you have configured the transaction log to use multiple log files.
SQL Server also uses the auto grow feature
to reduce the potential of running out of transaction log space. The
log files are truncated after a successful backup of the transaction
log and can be reused.
The amount of disk space that you need to store log files is a
factor of the number and size of the log files and the length of time
between full backups of the database.
When you install and configure Content Manager OnDemand, you set parameters that determine
the number and size of the log files and where Content Manager OnDemand should store
the log files.
