[ms] fix planning bug with rewritten constants: when removing some source for a const due to relation constraints, we should propagate this change to other constants coming from the same original variable
Schema of the data
------------------
First take a look at the data schema_ then try to remember that you are browsing
through a heap of data by applying stylesheets to the results of queries. This
site is not a content management system with items placed in folders. It is an
interface to a database which applies a view to retreived data.
.. _schema: schema