This involved changes to the driver interface as well as the database
schemata. The most significantly altered queries were for article
selection and marking, which relied upon unusual features of SQLite.
Overall query efficiency should not be adversely affected (it may have
even imprved) in the common case, while very rare cases (not presently
triggered by any REST handlers) require more queries.
One notable benefit of these changes is that functions which query
articles can now have complete control over which columns are returned.
This has not, however, been implemented yet: symbolic column groups are
still used for now.
Note that PostgreSQL still fails many tests, but the test suite runs to
completion. Note also that one line of the Database class is not
covered; later changes will eventually make it easier to cover the line
in question.
Tests for different drivers will have their own files, but all derive
from a common prototype test series where applicable, similar to the
existing arrangement for database function tests. However, the prototype
will reside with other test cases rather than in the library path. The
database function test series will hopefully be moved as well in time.