cmr-field-name

only one 

Specifies the Java identifier of a field. Must match the value of the cmr-field-name subelement of the cmr-field that is being mapped.

column-pair

one or more 

Specifies the pair of columns that determine the relationship between two database tables. 

fetched-with

zero or one 

Specifies the fetch group for this CMR field’s relationship.