[SoC] SoC report: Geo-BI dashboards
Etienne Dube
etdube at gmail.com
Fri Jul 18 16:09:15 EDT 2008
Hi everybody,
1. What did I do this week:
- Implemented the serialization of OLAP CellSets. The result of a query
is returned as a JSON object to the client as part of the response
(along the GeoJSON data). This will allow other dashboard components
(crosstabs, charts) to display another view of the data (synchronized
with the map view).
- Investigated a way to implement OLAP operators. It turns out that
there isn't a way in olap4j to manipulate and transform an existing MDX
query. This is planned as part of the final specification, but hasn't
been implemented yet. This is a major blocking point, and I will have to
implement at least part of this functionality myself. I'm investigating
the way JPivot (a Java/JSP based web OLAP client) is managing this for
basic OLAP navigation (drill-down on a member and so on). However,
JPivot is coupled direcly to Mondrian (it hasn't been updated to use the
olap4j API) and isn't stateless (the server maintains a state with the
current execution context of the client, i.e. current MDX query, result
axes, etc. and sets a cookie on the client with the session ID). I would
prefer a stateless way of doing this, even if the client has to submit
some information about its current context on each invocation of the
servlet. Moreover, I want to keep using the olap4j API because
Mondrian's native API is on the way to be deprecated. This task will
require serious efforts to overcome, and will be my sole focus for the
next two weeks (and possibly more). This is an absolute requirement to
get a working application which is generic and usable with any data cube.
I have discussed this problem with my mentor and we have decided to bite
the bullet and work on solving this, as it will enable the development
of new OLAP operators in a faster and easier way. It could also be an
important and welcome contribution to the olap4j API (www.olap4j.org).
However, the time needed for this task means that other planned features
(more mapping styles, legends, ...) will probably not be fully
implemented before the end of SoC.
2. What do I plan on doing next week:
- Continue working on a way to implement MDX query transformations and
OLAP operators.
3. Am I blocked on anything:
- The problem with OLAP operators/query transformations was unexpected,
but it is not really blocking as I'm working on a solution. See above.
Etienne
More information about the Soc
mailing list