OLAP or ALTP at reporting Tools

should I use OLAP or OLTP for reporting tools like BIRT, Jasper Rep开发者_Python百科ort... ? I want to build ad - hoc many documents (e.g. 1000000).

Just to extend on icCube's comment and provide an answer.

If you want to build many documents (in the order of millions), you probably do have data that are queried more than they are updated, and you might want an OLAP system, especially if your documents need aggregation of data (summing, counting) in hierarchies of your data (weekly, monthly, yearly aggregations).

If you have data that frequently flow into your database, like stock market data, you would definitely want a OLTP system.

You might need neither, and go mainstream with a RDBMS.