From bc9e2a37ec4e51c2468ec277210b1a1b227ae8d8 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Tue, 21 Mar 2023 11:25:25 -0700
Subject: [PATCH] Improved performance of cosine distance

---
 CHANGELOG.md | 1 +
 src/vector.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05a62d6..a3a4eb8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## 0.4.1 (unreleased)
 
+- Improved performance of cosine distance
 - Fixed index scan count
 
 ## 0.4.0 (2023-01-11)
diff --git a/src/vector.c b/src/vector.c
index c287c03..7c0cf4a 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -568,7 +568,7 @@ cosine_distance(PG_FUNCTION_ARGS)
 		normb += bx[i] * bx[i];
 	}
 
-	PG_RETURN_FLOAT8(1 - (distance / (sqrt(norma) * sqrt(normb))));
+	PG_RETURN_FLOAT8(1 - (distance / sqrt(norma * normb)));
 }
 
 /*