Setup a new database
Here is a small tutorial to setup a new database and how to handle it.
First, go to options and create a new database (1).

The location of the database will be displayed in this text box (2).

Afterwards set checkbox for Database/Measurement (3) to record laps.
A sub-directory is created to store the measurement files.
From now on each lap is recorded in one measurement file (zipped), stored in the sub-directory. To keep the overview of your lap-measurement-files an entry in your just created SQL-Database is created.
Save settings.
Once you’ve collected some data, you can quickly access it by using SQL query commands.
Go to Database.
Here some examples of queries:
To show all database entries:
SELECT * FROM Database
To set some filter:
SELECT * FROM Database WHERE Track = 'Melbourne'
The WHERE clause can be combined with AND, OR, and NOT operators.
SELECT * FROM Database WHERE Track = 'Melbourne' AND LapTime < 127
Please note that you have to enter LapTime queries in seconds.
There some predefined filters accessible via a pull-down menu. These are combined by AND.
By the ORDER BY keyword, you can sort the result-set in ascending or descending order. (ASC|DESC)
SELECT * FROM Database WHERE WHERE Track = 'Melbourne' AND LapTime < 127 ORDER BY DRS1 DESC
The BETWEEN operator selects values within a given range.
SELECT * FROM Database WHERE WHERE Fuel BETWEEN 20 AND 30
These are the basic commands in SQL syntax.
Further functionality:
You can mark/unmark your favorite database entries by the context menu. (See the result in the Favorite column).
The Show-button (or in the context menu) leads to TDA (Telemetry Data Analyzer). This feature does not exist yet but is coming soon. End of 3Q/2018.