Since Pentaho uses ROLAP mode (which basically means it runs the query on the source at Run-time), I wanted to understand if anyone has run into performance issues? If anyone has performance benchmarks for using Pentaho for operational BI that they can share, that would be great!
We are using Pentaho as ETL tool as well for BI from almost 5 years and There are no performance issues.
Performance issues will exist if there are problems with your underlying db
Pentaho will run against the database , you will run into performance issues unless your database will be fit for your needs. so if you try to work with big data or just more than few million rows its time to get a in memory / columnar data warehouse like infobright / infinidb : open source (infinidb closed recently - but the DB is very good and free) or others like : exasol , redshift, vertica...
for more information about ETL with pentaho please enter pentahokettletutorial.com/