Pentaho Mondian : Mondrian Schema xml Vs Pentaho metadata domain xmi Vs CDA cda files

I have been exploring the Pentaho ecosystem. Please forgive any naive things in the question.

There are a couple of things about these config files ( containing domains names and its mappings etc ) th开发者_Python百科at I can't seem to put my finger on.

So, if you use mondrian directly, you setup these xml config files. Now, suppose I use Pentaho BI server instead of just plan mondrian, then there are these metadata domain xmi files in the solution repository.

Q1) Do these pentaho metadata domain xmi files obviate the need for the mondrian schema xml files ?

Now, also CDA ( community dashboard access ) looks interesting. And if I install this plugin there would be .cda config files in the solution repository. The cda files contain both connection and also domain mapping details.

Q2) Do these cda files obviate the need to the two config files discussed in Q1 ?

Q3) Suppose I want to use olap4j to write an mdx query to Pentaho BI server referencing a cda file. Does that question make sense ?

thanks

XMI files are purely for the adhoc reporting wizard - nothing to do with analysis/olap or mondrian.

mondrian.xml are the mondrian schema files to allow you to use the OLAP engine. Whether you use olap in the biserver or not you'll need a schema file to use mondrian

CDA files are a buffer between the underlying data source and the dashboard front end. Again if you want to use mondrian/olap underneath (which you will want to with a dashboard) then you need a mondrian schema first. CDA can cache too which is neat. CDA can access virtually any data source because it can also use Kettle/PDI as a data source - and that can read anything.

You can put an MDX query into CDA so there's no need to use olap4j. CDA actually uses the PRD libraries to talk to mondrian - it's all nicely incestuous! :) If you want to use the results of a query in your own app/front end then CDA returns a JSON dataset which you can play with.

Alternatively look at saiku - thats geared up for providing an easy way to access data from Mondrian for user interface developers.

Finally you wont get many pentaho answers on here - the Forum or the IRC channel is a much better place to go with questions like these!