Clair will now use a YAML configuration file instead of command line
arguments as the number of parameters grows.
Also, Clair now exposes a Boot() func that allows everyone to easily
create their own project and load dynamically their own fetchers/updaters.
subject, predicate, object and labels are not indexed, thus, using a where clause on these fields for the DELETE statement does a full-table scan. Using *_hash columns instead will use the indexes.
It appears that preparing an INSERT statement on PostgreSQL actually makes it expecting to receive INSERTs and thus, it create some kind of locks for it. If instead, you only send him DELETE statements, it will indefinitely wait for an INSERT and hung.