Index expiration time
Index expiration time

The new datastore pricing (effective July 2016) no longer imposes a cost
penalty for indexed columns (other than storage costs).  It also makes
entity deletions more affordable.  This combination makes it feasible to
garbage collect expired kv values.

The expiration index is the first step in this direction.  It lets us
quickly find entities which have expired.  The next step will be a
function which could be run inside a cron job to delete expired
entities.

mndrix/aeds