3-44 IBM Informix OnLine Database Server Administrator’s Guide
Archive Types
An online archive is an archive that is created while OnLine is online and
databaseserver processes are modifying data. Allocation of some disk pages
in dbspaces and blobspaces might be temporarily frozen during an online
archive. (Refer topage 4-30 for an explanation of how OnLine manages an
online archive.)
Aquiescent archive is an archive that is created while OnLine is in quiescent
mode. No database activity occurs while the archive is being made.
Aremote archive is an archive that is created on a tape device managed by
another host machine. You can create a remote archive in either online or
quiescent mode. (Refer to page 3-53 for instructions on how to specify an
archive device on another machine.)
Level-0 Archive
Alevel-0archive is the baseline archive. It contains a copy of every used disk
page (dbspace and blobspace) that would be needed to restore an OnLine
system to that point in time. All disk page copies on the tape reflect the
contents of the disk pages at the time the level-0 archive began. This is true
even for online archives, which are created while users continue to process
data.(Refer to page 4-30 for a description of what happens during an OnLine
archive.)
During a level-0 archive, OnLine copies disk pages selectively; not every
usedpage is copied. Dbspace pages allocated to OnLine but not yet allocated
to an extent are ignored. (Refer topage 2-114 for a detailed discussion of
extents and allocating pages to an extent.) Pages allocated to the logical log
orphysical log are ignored. Temporary tables are scanned and can be copied
during a level-0 archive.
Blobspace blobpages are scanned. OnLine might need to copy specific disk
pages that contain deleted blobs because of requirements related to the
restore procedure. (Refer topage 4-45.)
Mirror chunks are not archived if their primary chunks are accessible.
The configuration file is not part of an OnLine archive.
Refer topage 4-37 for more information about the archive criteria and how
OnLinedetermines whether or not a page should be copied to disk during a
level-0 archive.