ARTICLE
Shared Objects - States of Area Instance Versions
Area instance versions can have the following states.
"Building"
An area instance version that has a
change lock is being built. Change locks automatically create a
building version.
"Active"
The area instance version whose build or update was last released using
the DETACH_COMMIT method (and a
database commit in the case of transactional areas) is active. All read
locks are automatically set to the current active version.
"Obsolete"
If during read access to the currently active version of the build, a
new version becomes complete, the new version becomes active and the
version that was previously active becomes obsolete. The
read locks on the obsolete version
remain until the read process is complete; new read locks for the area
instance are always set on the active version, however.
"Expired"
Once the last read lock on an obsolete version is removed, the version
expires; that is, it is deleted by the garbage collector. No locks can
be set on expired versions and they are not considered when the version
number is determined.
In an area without area instance versioning, there is always only one
area instance version, which is available in one of the states mentioned
above. In an area with versioning, there can be different states in an
area instance at the same time:
Since there can be a maximum of one change lock on an area instance,
there is a maximum of one building version for each area instance at any
given time.
There is a maximum of one active version for each area instance.
Depending on the maximum version number, several obsolete versions can
exist in parallel.
Note
If there are a large number of obsolete area instance versions for an
area that still have read locks, but there is an updated version in an
active state, this can indicate a problem with the use of shared
objects.
Example
In a simple case with a maximum of two version, there can be a maximum
of:
One active version and one building version
One active version and one obsolete version
One building version and one obsolete version
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved