Fix comments an codebook size estimate

Author: tfeher

cpp/src/neighbors/detail/cagra/cagra_helpers.cpp

@@ -30,7 +30,7 @@ std::tuple<size_t, size_t, size_t, size_t> optimize_workspace_size(size_t n_rows
     mst_host = n_rows * index_size;                  // mst_graph_num_edges
     mst_host += n_rows * graph_degree * index_size;  // mst_graph allocated in optimize
     mst_host += n_rows * graph_degree * index_size;  // mst_graph allocated in mst_optimize
-    mst_host += n_rows * index_size * 7;             // vectors with _max_edges suffix
+    mst_host += n_rows * index_size * 7;             // Five vectors _edges suffix, and label, cluster_size vectors.
     mst_host_fixed += (graph_degree - 1) * (graph_degree - 1) * index_size;  // iB_candidates
     mst_host += mst_host_fixed;
   }

cpp/src/neighbors/ivf_pq_index.cu

@@ -828,12 +828,14 @@ size_t compressed_dataset_size(raft::resources const& res,
   constexpr static uint32_t kIndexGroupSize   = 32;
   constexpr static uint32_t kIndexGroupVecLen = 16;
 
-  size_t pq_chunk   = (kIndexGroupVecLen * 8) / params.pq_bits;
-  size_t pq_centers = idx.pq_len() * pq_book_size * params.pq_dim * sizeof(float);
+  size_t pq_chunk = (kIndexGroupVecLen * 8) / params.pq_bits;
+  size_t pq_centers =
+    (params.codebook_kind == codebook_gen::PER_SUBSPACE ? params.pq_dim : params.n_lists) *
+    idx.pq_len() * pq_book_size * sizeof(float);
   size_t pq_dataset = raft::ceildiv<size_t>(dataset.extent(0), kIndexGroupSize) * kIndexGroupSize *
                       raft::ceildiv<size_t>(params.pq_dim, pq_chunk) * kIndexGroupVecLen;
   size_t indices         = dataset.extent(0) * sizeof(int64_t);
-  size_t rotation_matrix = idx.rot_dim() * idx.rot_dim() * sizeof(float);
+  size_t rotation_matrix = idx.rot_dim() * idx.dim() * sizeof(float);
   size_t list_offsets    = (params.n_lists + 1) * sizeof(int64_t);
   size_t list_sizes      = params.n_lists * sizeof(int64_t);
   size_t centers         = params.n_lists * idx.dim_ext() * sizeof(float);

examples/cpp/CMakeLists.txt

@@ -16,8 +16,6 @@ include(rapids-export)
 include(rapids-find)
 
 # ------------- configure project --------------#
-set(CMAKE_CXX_STANDARD 20)
-set(CMAKE_CUDA_STANDARD 20)
 
 rapids_cuda_init_architectures(test_cuvs)