From 0c9b1597f275cc87eb577c6c83a83058b102033b Mon Sep 17 00:00:00 2001
From: Xiaoguang Zhu <smdsbz@qq.com>
Date: Tue, 9 Sep 2025 14:46:04 +0800
Subject: [PATCH] fix: deduce metric type from non-empty search result (#44222)

issue: https://github.com/milvus-io/milvus/issues/32262

The old implementation always takes metric type from the first sub
result, which may not always be valid. The fixed implementation returns
initialized metric type from sub results.

Signed-off-by: smdsbz <smdsbz@qq.com>
---
 internal/proxy/search_util.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/internal/proxy/search_util.go b/internal/proxy/search_util.go
index db8f5e080e..ec1f6b545d 100644
--- a/internal/proxy/search_util.go
+++ b/internal/proxy/search_util.go
@@ -602,9 +602,10 @@ func convertHybridSearchToSearch(req *milvuspb.HybridSearchRequest) *milvuspb.Se
 }
 
 func getMetricType(toReduceResults []*internalpb.SearchResults) string {
-	metricType := ""
-	if len(toReduceResults) >= 1 {
-		metricType = toReduceResults[0].GetMetricType()
+	for _, r := range toReduceResults {
+		if m := r.GetMetricType(); m != "" {
+			return m
+		}
 	}
-	return metricType
+	return ""
 }