Chris,
it is obviously difficult for me to compare the features that I can
offer to the rich set of the ones offered by a suite of
open-source/commercial softwares: in fact I don't have anything at the
moment on my desk!
In my opinion, the drafted plan that I'm considering could lead to a
better/cleaner set of dimensions and facts (derived by the OFBiz data
model); if in the process we will find good ways of integrating (or just
using) external tools (and I hope this will happen) I would be more than
happy to invest some time in their integration.
Maybe, it would be really helpful at this stage to find out what are the
*cons* of integrating an external suite for datawarehouse; for example,
since you did some experiments integrating such tools in OFBiz, what are
the problems (if any) you found using them with OFBiz? What are the
challenges we will have to resolve if we try to integrate them?
Thanks,
Jacopo
Chris Howe wrote:
Inline..
--- Jacopo Cappellato <[EMAIL PROTECTED]> wrote:
Chris,
first of all, thanks for your interest on this subject.
Please, see my comments inline:
Building ETL services and an initial star schema (that I guess is
what
you refer to with denormalized entities) is my primary goal now.
From the Pentaho site
* Mondrian - Open Source OLAP Server
* JFreeReport - Open Source Reporting
* Kettle - Open Source Data Integration (E.T.T.L.) <<
* Pentaho - Comprehensive Open Source BI Suite
* Weka - Open Source Data Mining
ETTL means...
* Extraction of data from one or more databases
* Transport of data from one location to an other
* Transformation of data
* Loading of data in a data warehouse
So their's even has an extra "T" ;)
The star schema will be built in a relational database but
essentially
is composed of:
a fact table (e.g. "Sales Transactions")
a set of dimension tables (e.g. "Products", "Date", "Time", "Stores"
etc..)
Usually the fact table is only useful inside one star schema, while
dimensions are shared among many star schemas.
I'd like to build a common, based on best practices set of dimensions
(and a few fact tables that use them) derived from the OFBiz data
model.
You can then use the tool you want to run your reports/analysis
etc...
I don't know how Mondrian works, but by what you say here it seems
that
you can use Mondrian on top of these star schemas.
That is almost an exact description of what a cube is in Mondrian and
from what I understand Microsoft's OLAP as well
http://mondrian.pentaho.org/documentation/schema.php#Cube
