Fix parallel workers under the lead process in UI via ORDER BY

[kmoppel-cognite]

Currently they're jumping around annoyingly. Relevant for vers >= 9.6

[kmoppel-cognite]

Currently something like this happens:

[kmoppel-cognite]

Or such:

[kmoppel-cognite]

After patch:

[blogh]

Hi,

It has also been bugging me for a while.
Since we sort here afterwards. I wonder if we should ditch the sort in the query and add the pid sort in the sorted function.

@dlax do you have an opinion on this ?

[dlax]

Since we sort here afterwards. I wonder if we should ditch the sort in the query and add the pid sort in the sorted function.

Indeed, it might be worth trying:

diff --git a/pgactivity/activities.py b/pgactivity/activities.py
index da0689a..bcb989c 100644
--- a/pgactivity/activities.py
+++ b/pgactivity/activities.py
@@ -198,7 +198,7 @@ def sorted(processes: List[T], *, key: SortKey, reverse: bool = False) -> List[T
     """
     return builtins.sorted(
         processes,
-        key=lambda p: getattr(p, key.name) or 0,  # TODO: avoid getattr()
+        key=lambda p: (getattr(p, key.name) or 0, p.pid),  # TODO: avoid getattr()
         reverse=reverse,
     )

[dlax]

Indeed, it might be worth trying:

Pushed this suggestion into procs-sort branch, if you can give it a try; @blogh, @kmoppel-cognite.

[kmoppel-cognite]

@dlax Oh I see, sorted in code instead. But the above comment didn't work for me sadly - this did:

diff --git a/pgactivity/activities.py b/pgactivity/activities.py
index bcb989c..31636eb 100644
--- a/pgactivity/activities.py
+++ b/pgactivity/activities.py
@@ -198,7 +198,7 @@ def sorted(processes: List[T], *, key: SortKey, reverse: bool = False) -> List[T
     """
     return builtins.sorted(
         processes,
-        key=lambda p: (getattr(p, key.name) or 0, p.pid),  # TODO: avoid getattr()
+        key=lambda p: (getattr(p, key.name) or (p.duration, p.pid)),  # TODO: avoid getattr()
         reverse=reverse,
     )

[kmoppel-cognite]

Closing in favour of Python code based sorting #291