EDIT

This was observed with a locally running cdmlib-remote-webapp instance configured with 700 MB of Heap:

Left pane shows the cdmlib-remote-webapp instance*, right pane the Taxeditor.

[caryophyllales_spp] 14:34:40,792 WARN [qtp759156157-23][or.sp.re.su.RemoteInvocationTraceInterceptor] - Processing of HttpInvokerServiceExporter remote call resulted in fatal exception: eu.etaxonomy.cdm.api.service.IService.load
java.lang.OutOfMemoryError: GC overhead limit exceeded
    at java.util.HashMap.newNode(HashMap.java:1742)
    at java.util.HashMap.putVal(HashMap.java:630)
    at java.util.HashMap.put(HashMap.java:611)
    at java.util.HashSet.add(HashSet.java:219)
    at java.util.AbstractCollection.addAll(AbstractCollection.java:344)
    at org.hibernate.collection.internal.PersistentSet.endRead(PersistentSet.java:327)
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollection(CollectionLoadContext.java:234)
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:221)
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:194)
    at org.hibernate.loader.Loader.endCollectionLoad(Loader.java:1179)
    at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1143)
    at org.hibernate.loader.Loader.processResultSet(Loader.java:992)
    at org.hibernate.loader.Loader.doQuery(Loader.java:930)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:336)
    at org.hibernate.loader.Loader.doList(Loader.java:2611)
    at org.hibernate.loader.Loader.doList(Loader.java:2594)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2423)
    at org.hibernate.loader.Loader.list(Loader.java:2418)
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:501)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:371)
    at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216)
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1326)
    at org.hibernate.internal.QueryImpl.list(QueryImpl.java:87)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.bulkLoadLazyCollections(AdvancedBeanInitializer.java:533)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.bulkLoadLazies(AdvancedBeanInitializer.java:435)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.initializeNodeNoWildcard(AdvancedBeanInitializer.java:244)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.initializeNode(AdvancedBeanInitializer.java:125)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.initializeNodeRecursive(AdvancedBeanInitializer.java:105)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.initializeNodeRecursive(AdvancedBeanInitializer.java:107)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.initializeNodeRecursive(AdvancedBeanInitializer.java:107)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.initializeAll(AdvancedBeanInitializer.java:85)
    at eu.etaxonomy.cdm.persistence.dao.initializer.AdvancedBeanInitializer.initialize(AdvancedBeanInitializer.java:57)

At the test-server it takes ~700MB to load the matrix data without garbage collection