Metadata Standards Crosswalk (created by the Getty Research Institute, Revised 9 June 2009)
MARC Mappings (to various standards)
Why Use a Relational Cataloging Tool (J. Eklund, 2008 from VRA-L)
Strategies for Data Migration in the Age of CCO and VRA Core 4.0 (2007 Conference Session)
CCO; Section VII. DATABASE DESIGN AND RELATIONSHIPS, (pp. 20-27 online pdf)
Sample ER (“entity relationship”) diagrams of relational databases
VCat (simplified collapsed view; database written in Filemaker)
IRIS (simplified and edited collapsed view; database written in Filemaker)
Local mapping, creating local data dictionaries (using Excel or flat data)
The first step would be to create a mapping of your database export fields to VRA Core 4; all other maps or data dictionaries can proceed from that.
The following are mappings from VCat, but show the flat VRA Core 4 mappings used; they may be downloaded and freely adapted. Plug in your own local field names (replacing the VCat names column) and map (and manipulate data) accordingly.