We are looking at Lifecycle Query Engine (LQE) and Data Warehouse (DW).
The DW has been part of Jazz platform much sooner than the LQE and therefore it is more mature. It has well-documented schema and ready-to-use reports that are missing in LQE or as not developed as much as DW. Currently the component that is storing data to the data warehouse is called Data Collection Component (DCC) and it runs the data collection periodically. The DCC requests changes from the IBM® Engineering Lifecycle Management (ELM) applications and the changes are sent to the relational database.
The LQE is a newer addition to the Jazz platform. It does not store data into the data warehouse, instead it indexes and stores information locally. It does not use ETL jobs (extract, transform and load) like DCC, but instead it uses TRS (tracked resource sets) to make data available for indexing. It keeps the data refreshed nearly in real time. In order to report on project areas with configuration management enabled, you need to use this data source.
What are the pros and cons of each ?
Lifecycle Query Engine
PROS
- It enables you to report on project areas in RQM and DNG that have configurations enabled
- The data is refreshed in nearly real time
- More flexible schema-less reports (free text search)
- Data source for RELM
CONS
- Uses a lot of server resources (recommended to run on it’s own server)
- Can not report on historical trends of data as much as DCC
- Customizing queries requires SPARQL knowledge
Data Warehouse
PROS
- Has mature set of ready-to-use reports.
- Much richer history and metrics data
- If there are thousands of active users or over 5 milions resources it is recommended to use DW
- It does not use that many resources in comparison to the LQE.
- Data source of IBM Cognos and BIRT (RTC/RQM)
CONS
- Cannot report on projects with configurations enabled (apart from work items since those aren’t versioned)
- Not compatible with RELM.
- The data is not as actual as in LQE
If you have enough server resources it is completely fine to use both of these data sources and benefit from their advantages.
Note: There is one more different option that does not use LQE or DW as a data source – Rational Publishing Engine (RPE). This tool is not included with the ELM/CLM and you need to purchase separate license for it. This tool extracts data directly from the applications via REST API in order to generate reports (documents and spreadsheets).
