Advanced Topics - eXist: A NoSQL Database and Application Development Platform - page 432

</v:properties>
<v:diff>
<v:delete event= "start" ref= "1.3" />
<v:append ref= "1.3" >
<v:end name= "deceased" />
</v:append>
<v:delete event= "end" ref= "1.3" />
<v:delete ref= "1.4.1" />
<v:insert ref= "1.3" >
<v:start name= "deceased" />
</v:insert>
<v:insert ref= "1.4.1" > The British actor Michael Rennie worked as a car
salesman and factory manager before he turned to acting. A meeting
with a Gaumont-British Studios casting director led to Rennie's first
acting job - that of stand-in for Robert Young in Secret Agent
(1936), directed by Alfred Hitchcock. </v:insert>
</v:diff>
</v:version>
We can see that the second diff document contains both the changes we made in this
revision (i.e., updated text in the abstract element) as well as all changes from previ‐
ous revisions. This is because, as previously mentioned, each diff document is
between the current document and the document base revision.
If you wish to configure the VersioningTrigger for a collection in your database,
you need to add the following to the triggers element within your collection's con‐
figuration document ( collection.xconf ):
<triggers>
<trigger class= "org.exist.versioning.VersioningTrigger" >
<!--
Whether to try and avoid
write conflicts on versioned
documents.
Set to 'false' to avoid write conflicts,
or 'true' to ignore write conflicts and
overwrite the later revision.
-->
<parameter name= "overwrite" value= "false" />
</trigger>
</triggers>
It is worth noting that you can also interrogate document revisions from XQuery by
using the versioning XQuery module, as discussed in versioning .