1# Debug Tracks 2 3Debug Tracks are a way to display tabular results from running a PerfettoSQL 4query as a so-called "debug" track. Specifically, if the resultant table can 5be visualised in a slice format (ex: the 6[`slice`](sql-tables.autogen#slice) table) or counter format 7(ex: the [`counter`](sql-tables.autogen#counter) table), 8a debug track can be created from it. 9 10For a result table to be visualised, it should 11include: 12 131. A name (the name of the slice) column. 141. A non-null timestamp (the timestamp, in nanoseconds, at the start of the 15 slice) column. 161. (For `slice` tracks) a duration (the duration, in nanoseconds, of the slice) 17 column. 181. (Optionally) the name of a column to pivot 19 20 Note: Pivoting means allows you to create a single debug track per distinct 21 value in the selected "pivot" column. 22 23## Creating Debug `slice` Tracks 24 25To create `slice` tracks: 26 271. Run a SQL query, and ensure its results are `slice`-like (as described 28 above). 29  301. Navigate to the "Show Timeline" view, and click on "Show debug track" to set 31 up a new debug track. Select "slice" from the Track type dropdown. 32 33 Note that the names of the columns in the result table do 34 not necessarily have to be `name`, `ts`, or `dur`. Columns which 35 _semantically_ match but have a different name can be selected from the 36 drop-down selectors. 37 38  39 401. The debug slice track is visible as a pinned track near the top of the 41 Timeline view with slices from the table from which the track was created 42 (note that slices with no/zero duration will be displayed as instant events). 43 Debug tracks may be manually unpinned and will appear on the top of other 44 unpinned tracks. 45  46 471. (Optional) Pivoted `slice` tracks are created by selecting a value from the 48 "pivot" column. 49 50 Note: You can enter queries into the search box directly by typing `:` to 51 enter SQL mode. 52 53  54 55 This will result in a debug slice track created for each distinct pivot 56 value. 57 58  59 60## Creating Debug `counter` Tracks 61 62You can create new debug `counter` tracks by following similar steps to the ones 63mentioned above: 64 651. Run a SQL query, and ensure its results are `counter`-like (as described 66 above). 67 68  691. Navigate to the Timeline view, and click on "Show debug track" to set up a 70 new debug track. Select "counter" from the Track type dropdown and the 71 semantically matching column names of interest. 72 73  74 751. The counter track will appear as a pinned track near the top of the Timeline view. 76 77  78 791. (Optional) Pivoted `counter` tracks are created by selecting a value from the 80 "pivot" column. 81 82  83 84 This will result in a debug counter track created for each distinct pivot 85 value. 86 87  88
