Column name	Type	Description
conoid	oid	Foreign key constraint oid for many-to-one relationships, null for others.
refconoids	oid []	Oids of the foreign keys the one-to-one or many-to-many relationship is based on, null for many-to-ones.
srcname	name	Foreign key's name.
dstname	name	Foreign key's name used in the inverse relationship (null for many-to-one relationships).
src	oid	Source table's oid.
dst	oid	Destination table's oid.
helper	oid	Helper table oid for many-to-many relationships, null for others.
srcnspname	name	Source table's namespace.
srcrelname	name	Source table name.
dstnspname	name	Destination table's namespace.
dsterelname	name	Destination table name.
srcfields	smallint []	Column indices in the source table (referencing columns for many-to-one and one-to-one relationships, referenced for many-to-many relationships).
dstfields	smallint []	Column indices in the destination table (referenced columns).
helperfields	smallint []	Helper table's columns' indices for many-to-many relationships (referencing columns), null for others.
srcfnames	name []	Field names corresponding to srcfields.
dstfnames	name []	Field names corresponding to dstfields.
helperfnames	name []	Field names corresponding to helperfields.
type	character (1)	Relationship type; 't' for many-to-ones, 'o' for one-to-ones, 'm' for many-to-many relationships.
dst_is_pkey	boolean	Whether the destination columns are a primary key (currently unique indices aren't supported).

Foreign keys correspond to many-to-one relationships. These are represented by BXRelationshipDescription objects which are created for each row of type 'm'. BXOneToOneRelationshipDescriptions and BXHelperTableMTMRelationshipDescriptions correspond to one-to-one and many-to-many relationships. Each is based on foreign keys the oids of which are in the refconoids array.

In addition to inverse relationship names fetched from the database, each (many-to-one?) relationship can be queried by the name of the table the referencing column is in. This is also the preferred method.