The general guidance is that you segment your application domain into two categories - Online Transaction Processing (OLTP) and Online Analytical Processing (OLAP).
The OLAP data is populated from the OLTP data using queries (snapshot tables, materialized views etc., could be the implementation).
You then add/refresh data into the OLAP tables in a set frequency (for eg: daily, weekly, bi-weekly, monthly, quarterly, yearly etc.,).
The OLTP system has up-to-date realtime transactions. The OLAP data has snapshots as of a particular date. The OLAP data may be denormalized while the OLTP data is highly normalized. This makes the OLAP data optimized for reads while the OLTP data is optimized for writes.
The OLAP data is populated from the OLTP data using queries (snapshot tables, materialized views etc., could be the implementation).
You then add/refresh data into the OLAP tables in a set frequency (for eg: daily, weekly, bi-weekly, monthly, quarterly, yearly etc.,).
The OLTP system has up-to-date realtime transactions. The OLAP data has snapshots as of a particular date. The OLAP data may be denormalized while the OLTP data is highly normalized. This makes the OLAP data optimized for reads while the OLTP data is optimized for writes.