Solr/Lucene fieldCache OutOfMemory error sorting on dynamic field

Question

We have a Solr core that has about 250 TrieIntFields (declared as dynamicField). There are about 14M docs in our Solr index and many documents have

Answer 1

We have a way to rework the schema by keeping a single sort field. The dynamic fields we have are like relevance_CLASSID. The current schema has a unique key NODEID and a multi-valued field CLASSID - the relevance scores are for these class Ids. If we instead keep one document per classId per nodeId i.e. the new schema will have NODEID:CLASSID as unique key and store some redundant information across documents with the same NODEID, then we can sort on a single field relevance and do a filter query on CLASSID.