3-48 IBM Informix OnLine Database Server Administrator’s Guide
Plan the Archive Schedule
■Size and number of archives. The minimum number of archives is
just the single level-0 archive. The maximum number is three, one
archive of each level.
■Size and number of logical log files since the last archive.
Thesize of the level-0 archive is fixed because it is the sum of all in-use data.
The size of the level-1 archive is a function of the time between your level-0
archives.The more often you create level-0 archives, the smaller each level-1
archive will be. This same relationship holds between level-1 archives and
level-2 archives and between level-2 archives and the number of logical log
files.
Minimize Restore TimeUsethe following strategy to minimize the time needed to restore an OnLine
system:
■Createa level-0 archive as often as is practicable, perhaps every three
days.
■Create a level-1 archive daily.
■Do not use level-2 archives.
The time required for any possible restore is limited to the time needed to
read and process the following data:
■A level-0 archive, representing the whole system
■A level-1 archive, representing from one to three days’ activity
■Logical log files, representing less than a day’s work