Re: theory #1- there are commodity solutions to the queriable data warehouse problem, e.g. Vertica or Greenplum. Looking at these can give you an idea of what

Re: theory #1- there are commodity solutions to the queriable data warehouse problem, e.g. Vertica or Greenplum. Looking at these can give you an idea of what might be hard. You've just described Vertica pretty accurately (column-oriented storage, materialised on disk for particular query patterns, ad-hoc deletion comparatively costly). And ageing out in Vertica is easy- you just drop a partition. I can't imagine a custom system would be built without so e provision for this.