Improve compare.py output to use min times and better column titles (#6134)

* Minor: improve output of compare.py

* cleanup

Author: alamb

benchmarks/compare.py

@@ -20,7 +20,6 @@
 from __future__ import annotations
 
 import json
-import statistics
 from dataclasses import dataclass
 from typing import Dict, List, Any
 from pathlib import Path
@@ -33,8 +32,6 @@
     print("Try `pip install rich` for using this script.")
     raise
 
-MEAN_THRESHOLD = 5
-
 
 @dataclass
 class QueryResult:
@@ -64,14 +61,9 @@ def load_from(cls, data: Dict[str, Any]) -> QueryRun:
     def execution_time(self) -> float:
         assert len(self.iterations) >= 1
 
-        # If we don't have enough samples, median() is probably
-        # going to be a worse measure than just an average.
-        if len(self.iterations) < MEAN_THRESHOLD:
-            method = statistics.mean
-        else:
-            method = statistics.median
-
-        return method(iteration.elapsed for iteration in self.iterations)
+        # Use minimum execution time to account for variations / other
+        # things the system was doing
+        return min(iteration.elapsed for iteration in self.iterations)
 
 
 @dataclass
@@ -81,7 +73,6 @@ class Context:
     num_cpus: int
     start_time: int
     arguments: List[str]
-    branch: str
 
     @classmethod
     def load_from(cls, data: Dict[str, Any]) -> Context:
@@ -91,7 +82,6 @@ def load_from(cls, data: Dict[str, Any]) -> Context:
             num_cpus=data["num_cpus"],
             start_time=data["start_time"],
             arguments=data["arguments"],
-            branch=data["arguments"][9]
         )
 
 
@@ -119,17 +109,19 @@ def compare(
     noise_threshold: float,
 ) -> None:
     baseline = BenchmarkRun.load_from_file(baseline_path)
-    baselineBranch = baseline.context.branch
 
     comparison = BenchmarkRun.load_from_file(comparison_path)
-    comparisonBranch = comparison.context.branch
 
     console = Console()
 
+    # use basename as the column names
+    baseline_header = baseline_path.stem
+    comparison_header = comparison_path.stem
+
     table = Table(show_header=True, header_style="bold magenta")
     table.add_column("Query", style="dim", width=12)
-    table.add_column(baselineBranch, justify="right", style="dim", width=12)
-    table.add_column(comparisonBranch, justify="right", style="dim", width=12)
+    table.add_column(baseline_header, justify="right", style="dim")
+    table.add_column(comparison_header, justify="right", style="dim")
     table.add_column("Change", justify="right", style="dim")
 
     for baseline_result, comparison_result in zip(baseline.queries, comparison.queries):