SQL Performance Investigator (SQL-PI) is an extension to the standard Foglight for SQL Server Cartridge, and adds Real-time and historical data.
If you have used Performance Analysis for SQL Server, then SQL Performance Investigator should look very familiar to you.
Detailed instructions on how to enable the SQL PI Extensions:
The PI feature is also reflected on the databases dashboards. Under Monitoring Powered by should illuminate the green SQLPI indicator. The agents since now containing the SQL PI add on will also be referenced in the Databases SQLPI dashboards.
SQL Performance Investigator does require an add-on license, which can be obtained by contacting your sales rep.
The link below contains a video version of the information above.