SearchResults

This page documents both SearchResults and SingleResult. SearchResults wraps the results for all query vectors in a multi-NQ search. Each element of the inner list is a SingleResult containing the top-k hits for one query vector.

SearchResults

This class is returned by calling Results() on a SearchResponse or HybridSearchResponse.

SearchResults();
explicit SearchResults(std::vector<SingleResult>&& results);

Methods:

• const std::vector<SingleResult>& Results() const

  Returns one SingleResult per query vector, in the same order as the vectors were added to the request.

• const std::vector<float>& Recalls() const

  Recall values per query vector. Populated only when the search is run on a Zilliz Cloud instance with enable_recall_calculation set to true. Otherwise the vector is empty.

SingleResult

This struct holds the top-k hits for one query vector.

struct SingleResult {
    SingleResult(const std::string& pk_name, const std::string& score_name,
                 std::vector<FieldDataPtr>&& output_fields,
                 const std::set<std::string>& output_names);
};

using SingleResultPtr = std::shared_ptr<SingleResult>;

Methods:

• const std::vector<float>& Scores() const

  Similarity scores (distances) for each hit, in descending relevance order.

• IDArray Ids() const

  Primary key IDs of the top-k hits as an IDArray. Prefer using OutputField(PrimaryKeyName()) for typed access.

• const std::string& PrimaryKeyName() const

  The name of the primary key field as reported by the server. Useful when the caller does not know the PK field name.

• const std::string& ScoreName() const

  Name of the score field in the result (default: "score"). May be "_score" or "__score" if the collection has a field named "score".

• FieldDataPtr OutputField(const std::string& name) const

  Returns a named output field as a FieldDataPtr. Cast to the concrete type with std::dynamic_pointer_cast<FloatVecFieldData>(result.OutputField("vec")).

• const std::vector<FieldDataPtr>& OutputFields() const

  Returns all output fields.

• const std::set<std::string>& OutputFieldNames() const

  Names of the output fields requested in the search.

• Status OutputRows(EntityRows& rows) const

  Converts all hits to a vector of JSON-like row maps and stores them in rows.

• Status OutputRow(int i, EntityRow& row) const

  Converts hit at index i to a single JSON-like row map.

• uint64_t GetRowCount() const

  Number of hits returned.

Example

#include <milvus/MilvusClientV2.h>
using namespace milvus;

auto client = MilvusClientV2::Create();
client->Connect(ConnectParam("http://localhost:19530").WithToken("root:Milvus"));

std::vector<std::vector<float>> queries = {
    std::vector<float>(128, 0.1f),
    std::vector<float>(128, 0.2f),
};

SearchResponse response;
auto status = client->Search(
    SearchRequest()
        .WithCollectionName("my_collection")
        .WithAnnsField("vec")
        .WithLimit(5)
        .AddOutputField("id")
        .WithFloatVectors(std::move(queries)),
    response);
if (!status.IsOk()) {
    std::cout << status.Message() << std::endl;
}

for (size_t nq = 0; nq < response.Results().Results().size(); ++nq) {
    const SingleResult& result = response.Results().Results()[nq];
    std::cout << "Query " << nq << ": " << result.GetRowCount() << " hits\n";
    const auto& scores = result.Scores();
    auto id_field = std::dynamic_pointer_cast<Int64FieldData>(
        result.OutputField(result.PrimaryKeyName()));
    for (size_t i = 0; i < result.GetRowCount(); ++i) {
        std::cout << "  id=" << id_field->Value(i)
                  << " score=" << scores[i] << "\n";
    }
}