What we really would like to do is get bitmapped indexes integrated into
PostgreSQL so star queries could be done by combining the bitmap
indexes. TODO has:
* Use bitmaps to fetch heap pages in sequential order [performance]
* Use bitmaps to combine existing indexes [performance]
---------------------------------------------------------------------------
Clark C. Evans wrote:
> I'm looking around for a Relational OLAP solution based on
> PostgreSQL (and liberally licensed) to contribute to. If there
> is one out there, great, please forward. If not, is there anyone
> interested in joining a new project?
>
> I was thinking of a simple "star schema" with a single fact table
> to start. The fact table would have two sorts of columns, a
> "dimention" column or an "aggregate" column. These columns
> could be marked... perhaps using extra schema information
> on the relname/attname pair. Once this base schema was defined,
> we'd have to define what a "query" looks like, it appears that
> there is an "XML Analysis" which Hyperion and Microsoft use...
> although YAML would be cleaner. Once there is a query format
> (something simple at first) we could then implement a stored
> procedure which returns a result set when passed a query. The
> first implementation of the proceure would work directly against
> the fact table, doing the necessary aggregations. This bootstrap
> would then be given a nice regression test (with base data and
> expected query results).
>
> With this bootstrap in place, we could then focus on various
> query and/or cacheing optimizations. Further, we could then
> extend the scope to handle more than one fact table (multicube)
> which are attached via one or more shared dimentions, allowing
> the user to bounce between cubes. In parallel to this, someone
> could then be working on a user interface; I was thinking Python
> via Webware or mod_python using PIL.
>
> Anyway, please ping if you are working in this direction or would
> like to work in this direction. The result would be liberally
> licensed (BSDish) and ideally put into the "contrib".
>
> Best,
>
> Clark
>
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