| # Debug Tracks |
| |
| Debug Tracks are a way to display tabular results from running a PerfettoSQL |
| query as a new so-called "debug" track. Specifically, if the resultant table can |
| be visualised in a slice format (for example, the |
| [`slice`](sql-tables.autogen#slice) table), a debug track can be created from |
| it. |
| |
| For a result table to be able to be visualised in a slice format, it should |
| include: |
| |
| 1. A name (the name of the slice) column. |
| 1. A non-null timestamp (the timestamp, in nanoseconds, at the start of the |
| slice) column. |
| 1. (Optionally) a duration (the duration, in nanoseconds, of the slice) column. |
| |
| To create a new debug track: |
| |
| 1. Run a SQL query, and ensure its results are `slice`-like (as described |
| above). |
|  |
| 1. Navigate to the Timeline view, and click on "Show debug track" to set up a |
| new debug track. Note that the names of the columns in the result table do |
| not necessarily have to be `name`, `ts`, or `dur`. Columns which |
| *semantically* match but have a different name can be selected from the |
| drop-down selectors. |
|  |
| 1. The debug track is visible as a pinned track near the top of the Timeline |
| view with slices from the table from which the track was created (note that |
| slices with no/zero duration will be displayed as instant events). The debug |
| track may be manually unpinned and then it should appear on the top of other |
| unpinned tracks. |
|  |
