Q:

Custom storage extension - obtain keyword children TCM ids

Another question in my ongoing saga to implement a customised Deployer without requiring a Broker database. 
When publishing a taxonomy I can see the childKeyword nodes listed in the XML for any given keyword.  For example:
<tcmc:locations rdf:about="tcm:2260-13571-1024">
    <rdfs:label>The Middle East (ME)</rdfs:label>
    <rdfs:comment>The Middle East (ME)</rdfs:comment>
    <tcmt:key>ME</tcmt:key>
    <tcmt:isAbstract>false</tcmt:isAbstract>
    <tcmt:isRoot>true</tcmt:isRoot>
    <tcmt:metadata rdf:parseType="Literal"/>
    <tcmt:childKeyword rdf:resource="tcm:2260-13572-1024"/>
    <tcmt:childKeyword rdf:resource="tcm:2260-13573-1024"/>
    <tcmt:childKeyword rdf:resource="tcm:2260-13574-1024"/>
</tcmc:locations>

I'm implementing a TaxonomyDAO to store keywords within Couchbase.  All of this is working fine, I've implemented the various methods to store each item in the taxonomy, and able remove the entire taxonomy. 
I would like to be able to store a references to a Keyword's children within the Couchbase document.  The TaxonomyItem passed to the store method has a hasChildren boolean, but no property to return the actual child items themselves. 
My question: Is there a mechanism to obtain a list of child keywords for a keyword, when publishing a taxonomy?  A list of Ids will do. 

A:

This can be achieved without a Deployer extension.  Within my storage extension CouchbaseFactoryDAO there are a few useful methods which handle the transaction:

startTransaction
commitTransaction
rollbackTransaction
rollbackTimedOutTransaction

I created a map of transaction objects.  Each transaction object contains a map of TaxonomyItems (as well as associated ItemMeta), that is populated by the store methods of the CouchbaseTaxonomyDAO, and CouchbaseItemDAO classes. 
When the factory commitTransaction method is called, I have all the information in my transaction object.  Iterate through the maps, merging the metadata, and setting the child references (as each Keyword has it's parent id). 
Once this is complete, it's just a case of inserting into Couchbase.