enhance: add channel num for queryHook optimization (#35104)

At most cases, data in each channel is almost evenly distributed, we
could utilize the channel num info to optimize searh param in queryHook

Signed-off-by: chasingegg <chao.gao@zilliz.com>

internal/querynodev2/optimizers/query_hook.go

@@ -66,6 +66,9 @@ func OptimizeSearchParams(ctx context.Context, req *querypb.SearchRequest, query
 			common.WithOptimizeKey: paramtable.Get().AutoIndexConfig.EnableOptimize.GetAsBool(),
 			common.CollectionKey:   req.GetReq().GetCollectionID(),
 		}
+		if withFilter && channelNum > 1 {
+			params[common.ChannelNumKey] = channelNum
+		}
 		err := queryHook.Run(params)
 		if err != nil {
 			log.Warn("failed to execute queryHook", zap.Error(err))

pkg/common/common.go

@@ -109,6 +109,7 @@ const (
 	SegmentNumKey   = "segment_num"
 	WithFilterKey   = "with_filter"
 	DataTypeKey     = "data_type"
+	ChannelNumKey   = "channel_num"
 	WithOptimizeKey = "with_optimize"
 	CollectionKey   = "collection"