Indexes

The main index interfaces are listed here and in the next sections. Refer to this table when making decisions about which index to use.

• svs::Vamana - A graph-based similarity search engine suitable for high recall, high throughput, and low latency.

• svs::Flat - An exhaustive search engine. Provides precise results at the expense of low throughput and high latency for large datasets.

Contents

• Vamana Index
  • Vamana
    • Vamana::search_parameters_type
    • Vamana::get_alpha()
    • Vamana::get_max_candidates()
    • Vamana::save()
    • Vamana::size()
    • Vamana::dimensions()
    • Vamana::query_types()
    • Vamana::can_change_threads()
    • Vamana::get_num_threads()
    • Vamana::set_num_threads()
    • Vamana::assemble()
    • Vamana::build()
  • Helper Classes
    • VamanaBuildParameters
      • VamanaBuildParameters::alpha
      • VamanaBuildParameters::graph_max_degree
      • VamanaBuildParameters::window_size
      • VamanaBuildParameters::max_candidate_pool_size
      • VamanaBuildParameters::prune_to
      • VamanaBuildParameters::use_full_search_history
    • VamanaSearchParameters
      • VamanaSearchParameters::buffer_config_
      • VamanaSearchParameters::search_buffer_visited_set_
      • VamanaSearchParameters::prefetch_lookahead_
      • VamanaSearchParameters::prefetch_step_
  • Example
    • Preamble
    • Building and Index
    • Searching the Index
    • Saving the Index
    • Reloading a Saved Index
    • Using Vector Compression
    • Building using Vector Compression
    • Entire Example
• Flat Orchestrator
  • Flat
    • Flat::search_parameters_type
    • Flat::size()
    • Flat::dimensions()
    • Flat::query_types()
    • Flat::can_change_threads()
    • Flat::get_num_threads()
    • Flat::set_num_threads()
    • Flat::assemble()
    • Flat::AssembleTag

Compatible Loaders

The table below lists the compatibility between different index and the different kinds of dataset (e.g., uncompressed, lvq etc).

Index and Loader Compatibility Matrix

Loader / Right: Index	svs::Vamana	svs::Flat
svs::VectorDataLoader	Build and Search	Search Only
svs::quantization::lvq::LVQDataset	Build and Search	Search Only

Note

As an implementation detail, the indexes here are type-erased instances of more specialized, heavily templated implementations. These low level implementations generally have a similar API to the top level indexes and can be more expressive as functions calls do not have to cross a virtual function boundary. However, this specialization results in a different concrete type for each implementation which can be undesireable. More documentation regarding the low level implementation will be available in the future.