PERF: Increase threashold for using binary search in IndexEngine (#54746

) * Increase threashold for using binary search in IndexEngine * Add an entry to the latest whatsnew * Improve entry in the lastest whatsnew --------- Co-authored-by: Patrick Hoefler <61934744+phofl@users.noreply.github.com>
pandas-dev · Aug 26, 2023 · 48f5a96 · 48f5a96
1 parent 9939c32
commit 48f5a96
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/doc/source/whatsnew/v2.2.0.rst b/doc/source/whatsnew/v2.2.0.rst
@@ -153,7 +153,7 @@ Deprecations
 
 Performance improvements
 ~~~~~~~~~~~~~~~~~~~~~~~~
--
+- Performance improvement when indexing with more than 4 keys (:issue:`54550`)
 -
 
 .. ---------------------------------------------------------------------------

diff --git a/pandas/_libs/index.pyx b/pandas/_libs/index.pyx
@@ -375,7 +375,7 @@ cdef class IndexEngine:
         # map each starget to its position in the index
         if (
                 stargets and
-                len(stargets) < 5 and
+                len(stargets) < (n / (2 * n.bit_length())) and
                 not na_in_stargets and
                 self.is_monotonic_increasing
         ):