Update IVF_PQ to set memory_budget in constructor, support preload feature_vectors and metadata only modes

apis/python/src/tiledb/vector_search/index.py

@@ -186,15 +186,20 @@ def _query_with_driver(
         def query_udf(index_type, index_open_kwargs, query_kwargs):
             from tiledb.vector_search.flat_index import FlatIndex
             from tiledb.vector_search.ivf_flat_index import IVFFlatIndex
+            from tiledb.vector_search.ivf_pq_index import IVFPQIndex
             from tiledb.vector_search.vamana_index import VamanaIndex
 
             # Open index
             if index_type == "FLAT":
                 index = FlatIndex(**index_open_kwargs)
             elif index_type == "IVF_FLAT":
                 index = IVFFlatIndex(**index_open_kwargs)
+            elif index_type == "IVF_PQ":
+                index = IVFPQIndex(**index_open_kwargs)
             elif index_type == "VAMANA":
                 index = VamanaIndex(**index_open_kwargs)
+            else:
+                raise ValueError(f"Unsupported index_type: {index_type}")
 
             # Query index
             return index.query(**query_kwargs)

apis/python/src/tiledb/vector_search/ingestion.py

@@ -3071,6 +3071,8 @@ def consolidate_and_vacuum(
                 uri=index_group_uri, memory_budget=1000000, config=config
             )
         elif index_type == "IVF_PQ":
-            return ivf_pq_index.IVFPQIndex(uri=index_group_uri, config=config)
+            return ivf_pq_index.IVFPQIndex(
+                uri=index_group_uri, memory_budget=1000000, config=config
+            )
         else:
             raise ValueError(f"Not supported index_type {index_type}")

apis/python/src/tiledb/vector_search/ivf_pq_index.py

@@ -37,6 +37,12 @@ class IVFPQIndex(index.Index):
         If not provided, all index data are loaded in main memory.
         Otherwise, no index data are loaded in main memory and this memory budget is
         applied during queries.
+    preload_k_factor_vectors: bool
+        When using `k_factor` in a query, we first query for `k_factor * k` pq-encoded vectors,
+        and then do a re-ranking step using the original input vectors for the top `k` vectors.
+        If `True`, we will load all the input vectors in main memory. This can only be used with
+        `memory_budget` set to `-1`, and is useful when the input vectors are small enough to fit in
+        memory and you want to speed up re-ranking.
     open_for_remote_query_execution: bool
         If `True`, do not load any index data in main memory locally, and instead load index data in the TileDB Cloud taskgraph created when a non-`None` `driver_mode` is passed to `query()`.
         If `False`, load index data in main memory locally. Note that you can still use a taskgraph for query execution, you'll just end up loading the data both on your local machine and in the cloud taskgraph.
@@ -48,14 +54,25 @@ def __init__(
         config: Optional[Mapping[str, Any]] = None,
         timestamp=None,
         memory_budget: int = -1,
+        preload_k_factor_vectors: bool = False,
         open_for_remote_query_execution: bool = False,
         **kwargs,
     ):
+        if preload_k_factor_vectors and memory_budget != -1:
+            raise ValueError(
+                "preload_k_factor_vectors can only be used with memory_budget set to -1."
+            )
+        if preload_k_factor_vectors and open_for_remote_query_execution:
+            raise ValueError(
+                "preload_k_factor_vectors can only be used with open_for_remote_query_execution set to False."
+            )
+
         self.index_open_kwargs = {
             "uri": uri,
             "config": config,
             "timestamp": timestamp,
             "memory_budget": memory_budget,
+            "preload_k_factor_vectors": preload_k_factor_vectors,
         }
         self.index_open_kwargs.update(kwargs)
         self.index_type = INDEX_TYPE
@@ -65,8 +82,20 @@ def __init__(
             timestamp=timestamp,
             open_for_remote_query_execution=open_for_remote_query_execution,
         )
-        # TODO(SC-48710): Add support for `open_for_remote_query_execution`. We don't leave `self.index`` as `None` because we need to be able to call index.dimensions().
-        self.index = vspy.IndexIVFPQ(self.ctx, uri, to_temporal_policy(timestamp))
+        strategy = (
+            IndexLoadStrategy.PRELOAD_VECTORS_FOR_RERANKING
+            if preload_k_factor_vectors
+            else IndexLoadStrategy.ONLY_METADATA
+            if open_for_remote_query_execution
+            else IndexLoadStrategy.DEFAULT
+        )
+        self.index = vspy.IndexIVFPQ(
+            self.ctx,
+            uri,
+            0 if memory_budget == -1 else memory_budget,
+            to_temporal_policy(timestamp),
+            strategy,
+        )
         self.db_uri = self.group[
             storage_formats[self.storage_version]["PARTS_ARRAY_NAME"]
         ].uri
@@ -125,16 +154,9 @@ def query_internal(
         if not queries.flags.f_contiguous:
             queries = queries.copy(order="F")
         queries_feature_vector_array = vspy.FeatureVectorArray(queries)
-
-        if self.memory_budget == -1:
-            distances, ids = self.index.query_infinite_ram(
-                queries_feature_vector_array, k, nprobe, k_factor
-            )
-        else:
-            distances, ids = self.index.query_finite_ram(
-                queries_feature_vector_array, k, nprobe, self.memory_budget, k_factor
-            )
-
+        distances, ids = self.index.query(
+            queries_feature_vector_array, k=k, nprobe=nprobe, k_factor=k_factor
+        )
         return np.array(distances, copy=False), np.array(ids, copy=False)
 
 

apis/python/src/tiledb/vector_search/module.cc

@@ -18,6 +18,7 @@
 #include "detail/linalg/tdb_matrix.h"
 #include "detail/linalg/tdb_partitioned_matrix.h"
 #include "detail/time/temporal_policy.h"
+#include "index/index_defs.h"
 #include "utils/seeder.h"
 
 namespace py = pybind11;
@@ -1096,6 +1097,14 @@ PYBIND11_MODULE(_tiledbvspy, m) {
       .value("L2", DistanceMetric::L2)
       .export_values();
 
+  py::enum_<IndexLoadStrategy>(m, "IndexLoadStrategy")
+      .value("ONLY_METADATA", IndexLoadStrategy::ONLY_METADATA)
+      .value("DEFAULT", IndexLoadStrategy::DEFAULT)
+      .value(
+          "PRELOAD_VECTORS_FOR_RERANKING",
+          IndexLoadStrategy::PRELOAD_VECTORS_FOR_RERANKING)
+      .export_values();
+
   /* === Module inits === */
 
   init_kmeans(m);

apis/python/src/tiledb/vector_search/type_erased_module.cc

@@ -368,10 +368,8 @@ void init_type_erased_module(py::module_& m) {
       .def("dimensions", &IndexFlatL2::dimensions)
       .def(
           "query",
-          [](IndexFlatL2& index,
-             const FeatureVectorArray& vectors,
-             size_t top_k) {
-            auto r = index.query(vectors, top_k);
+          [](IndexFlatL2& index, const FeatureVectorArray& vectors, size_t k) {
+            auto r = index.query(vectors, k);
             return make_python_pair(std::move(r));
           });
 
@@ -422,13 +420,13 @@ void init_type_erased_module(py::module_& m) {
           "query",
           [](IndexVamana& index,
              const FeatureVectorArray& vectors,
-             size_t top_k,
+             size_t k,
              uint32_t l_search) {
-            auto r = index.query(vectors, top_k, l_search);
+            auto r = index.query(vectors, k, l_search);
             return make_python_pair(std::move(r));
           },
           py::arg("vectors"),
-          py::arg("top_k"),
+          py::arg("k"),
           py::arg("l_search"))
       .def(
           "write_index",
@@ -467,13 +465,22 @@ void init_type_erased_module(py::module_& m) {
           [](IndexIVFPQ& instance,
              const tiledb::Context& ctx,
              const std::string& group_uri,
-             std::optional<TemporalPolicy> temporal_policy) {
-            new (&instance) IndexIVFPQ(ctx, group_uri, temporal_policy);
+             size_t memory_budget,
+             std::optional<TemporalPolicy> temporal_policy,
+             IndexLoadStrategy index_load_strategy) {
+            new (&instance) IndexIVFPQ(
+                ctx,
+                group_uri,
+                memory_budget,
+                temporal_policy,
+                index_load_strategy);
           },
           py::keep_alive<1, 2>(),  // IndexIVFPQ should keep ctx alive.
           py::arg("ctx"),
           py::arg("group_uri"),
-          py::arg("temporal_policy") = std::nullopt)
+          py::arg("memory_budget") = 0,
+          py::arg("temporal_policy") = std::nullopt,
+          py::arg("index_load_strategy") = IndexLoadStrategy::DEFAULT)
       .def(
           "__init__",
           [](IndexIVFPQ& instance, py::kwargs kwargs) {
@@ -494,41 +501,18 @@ void init_type_erased_module(py::module_& m) {
           },
           py::arg("vectors"))
       .def(
-          "query_infinite_ram",
-          [](IndexIVFPQ& index,
-             const FeatureVectorArray& vectors,
-             size_t top_k,
-             size_t nprobe,
-             float k_factor) {
-            auto r = index.query(
-                QueryType::InfiniteRAM, vectors, top_k, nprobe, 0, k_factor);
-            return make_python_pair(std::move(r));
-          },
-          py::arg("vectors"),
-          py::arg("top_k"),
-          py::arg("nprobe"),
-          py::arg("k_factor") = 1.f)
-      .def(
-          "query_finite_ram",
+          "query",
           [](IndexIVFPQ& index,
              const FeatureVectorArray& vectors,
-             size_t top_k,
+             size_t k,
              size_t nprobe,
-             size_t memory_budget,
              float k_factor) {
-            auto r = index.query(
-                QueryType::FiniteRAM,
-                vectors,
-                top_k,
-                nprobe,
-                memory_budget,
-                k_factor);
+            auto r = index.query(vectors, k, nprobe, k_factor);
             return make_python_pair(std::move(r));
           },
           py::arg("vectors"),
-          py::arg("top_k"),
+          py::arg("k"),
           py::arg("nprobe"),
-          py::arg("memory_budget"),
           py::arg("k_factor") = 1.f)
       .def(
           "write_index",
@@ -603,24 +587,24 @@ void init_type_erased_module(py::module_& m) {
           "query_infinite_ram",
           [](IndexIVFFlat& index,
              const FeatureVectorArray& query,
-             size_t top_k,
+             size_t k,
              size_t nprobe) {
-            auto r = index.query_infinite_ram(query, top_k, nprobe);
+            auto r = index.query_infinite_ram(query, k, nprobe);
             return make_python_pair(std::move(r));
-          })  //  , py::arg("vectors"), py::arg("top_k") = 1, py::arg("nprobe")
+          })  //  , py::arg("vectors"), py::arg("k") = 1, py::arg("nprobe")
               //  = 10)
       .def(
           "query_finite_ram",
           [](IndexIVFFlat& index,
              const FeatureVectorArray& query,
-             size_t top_k,
+             size_t k,
              size_t nprobe,
              size_t upper_bound) {
-            auto r = index.query_finite_ram(query, top_k, nprobe, upper_bound);
+            auto r = index.query_finite_ram(query, k, nprobe, upper_bound);
             return make_python_pair(std::move(r));
           },
           py::arg("vectors"),
-          py::arg("top_k") = 1,
+          py::arg("k") = 1,
           py::arg("nprobe") = 10,
           py::arg("upper_bound") = 0)
       .def("feature_type_string", &IndexIVFFlat::feature_type_string)

apis/python/test/local-benchmarks.py

@@ -22,7 +22,10 @@
 from tiledb.vector_search.index import Index
 from tiledb.vector_search.ingestion import TrainingSamplingPolicy
 from tiledb.vector_search.ingestion import ingest
+from tiledb.vector_search.ivf_flat_index import IVFFlatIndex
+from tiledb.vector_search.ivf_pq_index import IVFPQIndex
 from tiledb.vector_search.utils import load_fvecs
+from tiledb.vector_search.vamana_index import VamanaIndex
 
 
 class RemoteURIType(Enum):
@@ -252,7 +255,7 @@ def save_charts(self):
         plt.xlabel("Average Query Accuracy")
         plt.ylabel("Time (seconds)")
         plt.title(f"Ingestion Time vs Average Query Accuracy {sift_string()}")
-        for idx, timer in self.timers:
+        for idx, timer in enumerate(self.timers):
             timer.add_data_to_ingestion_time_vs_average_query_accuracy(
                 markers[idx % len(markers)]
             )
@@ -265,7 +268,7 @@ def save_charts(self):
         plt.xlabel("Accuracy")
         plt.ylabel("Time (seconds)")
         plt.title(f"Query Time vs Accuracy {sift_string()}")
-        for idx, timer in self.timers:
+        for idx, timer in enumerate(self.timers):
             timer.add_data_to_query_time_vs_accuracy(markers[idx % len(markers)])
         plt.legend()
         plt.savefig(os.path.join(RESULTS_DIR, "query_time_vs_accuracy.png"))
@@ -295,6 +298,7 @@ def download_and_extract(url, download_path, extract_path):
 
 
 def get_uri(tag):
+    global config
     index_name = f"index_{tag.replace('=', '_')}"
     index_uri = ""
     if REMOTE_URI_TYPE == RemoteURIType.LOCAL:
@@ -346,7 +350,7 @@ def benchmark_ivf_flat():
         index_uri = get_uri(tag)
 
         timer.start(tag, TimerMode.INGESTION)
-        index = ingest(
+        ingest(
             index_type=index_type,
             index_uri=index_uri,
             source_uri=SIFT_BASE_PATH,
@@ -356,6 +360,10 @@ def benchmark_ivf_flat():
         )
         ingest_time = timer.stop(tag, TimerMode.INGESTION)
 
+        # The index returned by ingest() automatically has memory_budget=1000000 set. Open
+        # a fresh index so it's clear what config is being used.
+        index = IVFFlatIndex(index_uri, config)
+
         for nprobe in [1, 2, 3, 4, 5, 10, 20]:
             timer.start(tag, TimerMode.QUERY)
             _, result = index.query(queries, k=k, nprobe=nprobe)
@@ -386,7 +394,7 @@ def benchmark_vamana():
             index_uri = get_uri(tag)
 
             timer.start(tag, TimerMode.INGESTION)
-            index = ingest(
+            ingest(
                 index_type=index_type,
                 index_uri=index_uri,
                 source_uri=SIFT_BASE_PATH,
@@ -397,6 +405,8 @@ def benchmark_vamana():
             )
             ingest_time = timer.stop(tag, TimerMode.INGESTION)
 
+            index = VamanaIndex(index_uri, config)
+
             for l_search in [k, k + 50, k + 100, k + 200, k + 400]:
                 timer.start(tag, TimerMode.QUERY)
                 _, result = index.query(queries, k=k, l_search=l_search)
@@ -429,7 +439,7 @@ def benchmark_ivf_pq():
                 index_uri = get_uri(tag)
 
                 timer.start(tag, TimerMode.INGESTION)
-                index = ingest(
+                ingest(
                     index_type=index_type,
                     index_uri=index_uri,
                     source_uri=SIFT_BASE_PATH,
@@ -440,6 +450,10 @@ def benchmark_ivf_pq():
                 )
                 ingest_time = timer.stop(tag, TimerMode.INGESTION)
 
+                # The index returned by ingest() automatically has memory_budget=1000000 set. Open
+                # a fresh index so it's clear what config is being used.
+                index = IVFPQIndex(index_uri, config)
+
                 for nprobe in [5, 10, 20, 40, 60]:
                     timer.start(tag, TimerMode.QUERY)
                     _, result = index.query(