id	summary	reporter	owner	description	type	status	priority	milestone	component	resolution	keywords	cc	repo	theme
169	Package dependencies	dread	rgrp	"A 'Derived' relationship can be applied from one package to another.

e.g.
sussex-demography is derived from census-2001

'Derived' relationship is:
 * directional
 * many:many
 * stateful

'derived' table columns:
 * id (primary key)
 * source_package (foreign key)
 * result_package (foreign key)
 * description (markdown text)

Further tickets:

* WUI - package view - shows 'derives from package x' and 'derived package y' with UML-like diagram of x -> this package -> y
* WUI - package edit form - new option to say it 'derives from' or 'has derivation' and you select the appropriate
* REST if - expose reading and writing this property"	enhancement	new	major		ckan