This class is a faster alternative to DbRAMRelationN for relations that may become big, but in
counterpart it does not preserve the order of elements, so it cannot be used for lists whose
order is controlled by the user.
This class implements a general support for relation N, that may be used for any DBMS (not only
DbRAM); so, for some DBMSs, we may prefer to use this implementation instead of the DBMS's own
collections.
This class provides a mapping between "repository" strings (such as "tableColumns", "tablename",
etc.) and Generic meta fields (such as "m_components", "m_name", etc.).