Selecting a window in Perfetto UI, inspecting the main thread, RenderThread, and CPU states, then taking screenshots works well for one investigation. The harder question is whether another trace or device supports the same conclusion. I care more about being able to recompute that conclusion next time than about making one screenshot look convincing.

Part 11 covers PerfettoSQL and Trace Processor. The aim is straightforward: turn judgments made in the UI into queries that others can check, then use Python to run them across multiple traces. You do not need to become a SQL expert first. Treat a trace as a set of timestamped tables, and translate your visual assessment into a query you can run repeatedly.

The article follows one path: understand Trace Processor, express an assessment as a query over a defined time window, run it from the command line, process multiple traces with Python, and finally turn the results into stable metrics and Trace Summary output. Each step includes SQL you can reuse.