[wdmmg-dev] Removing aggregated entries

[Friedrich Lindenberg]

Hi all,

I've just pushed feature-no-aggreagte-entries, a branch without
aggregated entries. Creating this involved the following changes:

 * Re-implementing the views system to work against cubes (faster now)
 * Re-implementing the old aggregator API to work against cubes (fixes #119)
 * Remove most of the aggregation code
 * Remove all references to is_aggregate etc. from code base,
including entry-page entry browser

While this greatly simplifies OpenSpending, I'm sure Rufus will
disagree. Here are my arguments for merging this in:

 * Nobody wants to use aggregate entries: they are terribly
distracting in navigation and viewing them is weird.
 * We only ever created a partial set of aggregate entries and thus it
makes no sense to search them (obvious alternative here is to
implement full pre-agg, of course, but that in itself solves nothing)
 * They won't build compare-o-tron for us: for this we need something
with clear labels, i.e. a view that combines entities, classifiers and
entries and assigns each a unique value. Aggregate entries don't do
this.
 * Given that we seem to be having problems with the size of the
"entries" collection, we might not want to put aggregates in there,
where their retrieval is particularly time sensitive.
 * It makes things simpler. One aggregation system is better than two,
and the newer one works better.

What do people think?

- Friedrich