Many who are not exposed to Data Warehouse / Data Mining / Reporting won’t understand data properly.
Many times we are tempted to fetch reports from live database. Which is not correct.
Try to read about these two terms
Online analytical processing (OLAP)
Online transaction processing (OLTP)
Design database to query a date range for scheduling
Add index to required columns to avoid full table scans
Pentaho Data Integration (PDI, also called Kettle) is the component of Pentaho responsible for the Extract, Transform and Load (ETL) processes.
7 Steps to Data Warehousing
Finally google graphs are good to draw quick graphs for given data