### Description

Dynamic mappings can greatly help the getting started experience but they currently don't apply to all types, one example is `dense_vector`.

It's been suggested to automatically map float arrays as dense vectors when there are more than 100 values, or a heuristic along these lines.
server/src/main/java/org/elasticsearch/index/mapper/DocumentParserContext.java
}
    public final DocumentParserContext createChildContext(ObjectMapper parent) {
        return new Wrapper(parent, this);
    }
    /**
     * Return a new context that will be used within a nested document.
     */
    public final DocumentParserContext createNestedContext(NestedObjectMapper nestedMapper) {
        if (isWithinCopyTo()) {
            
            return this;
        }
        final LuceneDocument doc = new LuceneDocument(nestedMapper.fullPath(), doc());
        
        
        
        
        
        
        IndexableField idField = doc.getParent().getField(IdFieldMapper.NAME);
        if (idField != null) {
            
            
            
            doc.add(new StringField(IdFieldMapper.NAME, idField.binaryValue(), Field.Store.NO));
        } else {
            throw new IllegalStateException("The root document of a nested document should have an _id field");
        }
        doc.add(NestedPathFieldMapper.field(indexSettings().getIndexVersionCreated(), nestedMapper.nestedTypePath()));
        addDoc(doc);