Author: mreutegg
Date: Thu Jan 23 10:59:10 2014
New Revision: 1560631
URL: http://svn.apache.org/r1560631
Log:
OAK-301: Document Oak
- identifier and versioning differences
Modified:
jackrabbit/oak/trunk/oak-doc/src/site/markdown/differences.md
Modified: jackrabbit/oak/trunk/oak-doc/src/site/markdown/differences.md
URL:
http://svn.apache.org/viewvc/jackrabbit/oak/trunk/oak-doc/src/site/markdown/differences.md?rev=1560631&r1=1560630&r2=1560631&view=diff
==============================================================================
--- jackrabbit/oak/trunk/oak-doc/src/site/markdown/differences.md (original)
+++ jackrabbit/oak/trunk/oak-doc/src/site/markdown/differences.md Thu Jan 23
10:59:10 2014
@@ -196,6 +196,15 @@ The import behavior for [`IMPORT_UUID_CR
* The implementation in Oak is closer to what the JCR specification says:
*Incoming nodes are assigned newly created identifiers upon addition to the
workspace. As a result, identifier collisions never occur.*
* Oak uses a MVCC model where a session operates on a snapshot of the
repository. It is therefore very difficult to ensure new UUIDs only in case of
a conflict. Based on the snapshot view of a session, an existing node with a
conflicting UUID may not be visible until commit.
+Identifiers
+-----------
+
+In contrast to Jackrabbit 2.x, only referenceable nodes in Oak have a UUID
assigned. With Jackrabbit 2.x the UUID is only visible in content when the node
is referenceable and exposes the UUID as a `jcr:uuid` property. But using
`Node.getIdentifer()`, it is possible to get the UUID of any node. With Oak
this method will only return a UUID when the node is referenceable, otherwise
the identifier is the UUID of the nearest referenceable ancestor with the
relative path to the node.
+
+Versioning
+----------
+
+Because of the different identifier implementation in Oak, the value of a
`jcr:frozenUuid` property on a frozen node will not always be a UUID (see also
section about Identifiers). The property reflects the value returned by
`Node.getIdentifier()` when a node is copied into the version storage as a
frozen node. This also means a node restored from a frozen node will only have
a `jcr:uuid` when it is actually referenceable.
Security
--------
