diff --git a/internal/querynodev2/segments/segment.go b/internal/querynodev2/segments/segment.go
index 78401e5e73a0c..ac5383164cbc0 100644
--- a/internal/querynodev2/segments/segment.go
+++ b/internal/querynodev2/segments/segment.go
@@ -1040,7 +1040,11 @@ func (s *LocalSegment) innerLoadIndex(ctx context.Context,
 				return err
 			}
 			updateIndexInfoSpan := tr.RecordSpan()
-			if !typeutil.IsVectorType(fieldType) || s.HasRawData(indexInfo.GetFieldID()) {
+			// Skip warnup chunk cache when
+			// . scalar data
+			// . index has row data
+			// . vector was function output
+			if !typeutil.IsVectorType(fieldType) || s.HasRawData(indexInfo.GetFieldID()) || fieldSchema.IsFunctionOutput {
 				return nil
 			}
 
diff --git a/internal/querynodev2/segments/segment_loader.go b/internal/querynodev2/segments/segment_loader.go
index 390f4a460d6ef..554337f12329f 100644
--- a/internal/querynodev2/segments/segment_loader.go
+++ b/internal/querynodev2/segments/segment_loader.go
@@ -1505,7 +1505,7 @@ func getResourceUsageEstimateOfSegment(schema *schemapb.CollectionSchema, loadIn
 			if !estimateResult.HasRawData && !isVectorType {
 				shouldCalculateDataSize = true
 			}
-			if !estimateResult.HasRawData && isVectorType {
+			if !estimateResult.HasRawData && isVectorType && !fieldSchema.IsFunctionOutput {
 				mmapChunkCache := paramtable.Get().QueryNodeCfg.MmapChunkCache.GetAsBool()
 				if mmapChunkCache {
 					segmentDiskSize += binlogSize