Metadata Database Design Information and Background

The metadata database was initially created in 2007 and has evolved over time as our understanding of our needs became clearer.  We knew that the metadata database should support our user and data needs.  We tried, at first, to use a metadata standard but found them to be either overly complex or not sufficient for our needs.  Eventually, we realized that we could support any well designed standard by mapping our metadata database entries to the standard, and indeed we are working on doing that now (March 2010) by creating FGDC metadata entries for data that we are archiving at NODC.

This page will contain additional notes and comments that might help people (including ourselves!) better understand how the database evolved, what decisions dictated certain choices, how the design is evolving. 

A PDF image of the metadata database table organization is located at http://www.bco-dmo.org/files/bcodmo/schema_BCO-DMO.pdf and it contains several pages of notes describing the changes made to the database over time.

Parameters table and the Dataset_parameters table: 

The U.S. GLOBEC thesaurus and the U.S. JGOFS thesaurus were the starting points for the BCO-DMO "official" (and so-called) Parameters table.  The Parameters table is a MySQL table defining the "official" parameter (data variable or data column) names.  This is an evolving list which also seeks input from evolving ontologies (see for example the MMI web site http://marinemetadata.org/).  There is also a Dataset_parameters table containing the parameter names as used by each contributing scientist on a dataset (data object) basis.  There is an attempt to make a connection between the Dataset_parameters table the Parameters table and (eventually) an entry in the Dataset_parameters table pointing to some kind of conversion routine.  This is a long range goal, but it gives us the beginning for establishing "standard" parameter names and yet we are still able to support the reality that we get data with user supplied parameter names that do not conform to any standard.