Added basic support for float4 arrays

src/float4.c

@@ -0,0 +1,58 @@
+#include "postgres.h"
+
+#include "utils/array.h"
+
+/*
+ * Get the L2 distance between vectors
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(float4_l2_distance);
+Datum
+float4_l2_distance(PG_FUNCTION_ARGS)
+{
+	ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
+	ArrayType  *b = PG_GETARG_ARRAYTYPE_P(1);
+	float	   *ax = (float *) ARR_DATA_PTR(a);
+	float	   *bx = (float *) ARR_DATA_PTR(b);
+	float		distance = 0.0;
+	float		diff;
+
+	/* TODO Check rank, dimensions, and nulls */
+	int			dim = ARR_DIMS(a)[0];
+
+	/* Auto-vectorized */
+	for (int i = 0; i < dim; i++)
+	{
+		diff = ax[i] - bx[i];
+		distance += diff * diff;
+	}
+
+	PG_RETURN_FLOAT8(sqrt((double) distance));
+}
+
+/*
+ * Get the L2 squared distance between vectors
+ * This saves a sqrt calculation
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(float4_l2_squared_distance);
+Datum
+float4_l2_squared_distance(PG_FUNCTION_ARGS)
+{
+	ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
+	ArrayType  *b = PG_GETARG_ARRAYTYPE_P(1);
+	float	   *ax = (float *) ARR_DATA_PTR(a);
+	float	   *bx = (float *) ARR_DATA_PTR(b);
+	float		distance = 0.0;
+	float		diff;
+
+	/* TODO Check rank, dimensions, and nulls */
+	int			dim = ARR_DIMS(a)[0];
+
+	/* Auto-vectorized */
+	for (int i = 0; i < dim; i++)
+	{
+		diff = ax[i] - bx[i];
+		distance += diff * diff;
+	}
+
+	PG_RETURN_FLOAT8((double) distance);
+}

src/hnsw.c

@@ -33,6 +33,12 @@ HnswInit(void)
 					  HNSW_DEFAULT_EF_CONSTRUCTION, HNSW_MIN_EF_CONSTRUCTION, HNSW_MAX_EF_CONSTRUCTION
 #if PG_VERSION_NUM >= 130000
 					  ,AccessExclusiveLock
+#endif
+		);
+	add_int_reloption(hnsw_relopt_kind, "dimensions", "Number of dimensions",
+					  HNSW_DEFAULT_DIMENSIONS, HNSW_MIN_DIMENSIONS, HNSW_MAX_DIMENSIONS
+#if PG_VERSION_NUM >= 130000
+					  ,AccessExclusiveLock
 #endif
 		);
 
@@ -125,6 +131,7 @@ hnswoptions(Datum reloptions, bool validate)
 	static const relopt_parse_elt tab[] = {
 		{"m", RELOPT_TYPE_INT, offsetof(HnswOptions, m)},
 		{"ef_construction", RELOPT_TYPE_INT, offsetof(HnswOptions, efConstruction)},
+		{"dimensions", RELOPT_TYPE_INT, offsetof(HnswOptions, dimensions)},
 	};
 
 #if PG_VERSION_NUM >= 130000

src/hnsw.h

@@ -42,6 +42,9 @@
 #define HNSW_DEFAULT_EF_SEARCH	40
 #define HNSW_MIN_EF_SEARCH		1
 #define HNSW_MAX_EF_SEARCH		1000
+#define HNSW_DEFAULT_DIMENSIONS	-1
+#define HNSW_MIN_DIMENSIONS		1
+#define HNSW_MAX_DIMENSIONS		HNSW_MAX_DIM
 
 /* Tuple types */
 #define HNSW_ELEMENT_TUPLE_TYPE  1
@@ -131,6 +134,7 @@ typedef struct HnswOptions
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int			m;				/* number of connections */
 	int			efConstruction; /* size of dynamic candidate list */
+	int			dimensions;
 }			HnswOptions;
 
 typedef struct HnswBuildState
@@ -259,6 +263,7 @@ typedef struct HnswVacuumState
 /* Methods */
 int			HnswGetM(Relation index);
 int			HnswGetEfConstruction(Relation index);
+int			HnswGetDimensions(Relation index);
 FmgrInfo   *HnswOptionalProcInfo(Relation index, uint16 procnum);
 bool		HnswNormValue(FmgrInfo *procinfo, Oid collation, Datum *value, Vector * result);
 void		HnswCommitBuffer(Buffer buf, GenericXLogState *state);

src/hnswbuild.c

@@ -400,6 +400,7 @@ HnswGetMaxInMemoryElements(int m, double ml, int dimensions)
 	elementSize += sizeof(HnswNeighborArray) * (avgLevel + 1);
 	elementSize += sizeof(HnswCandidate) * (m * (avgLevel + 2));
 	elementSize += sizeof(ItemPointerData);
+	/* TODO Handle non-vector types */
 	elementSize += VECTOR_SIZE(dimensions);
 	return (maintenance_work_mem * 1024L) / elementSize;
 }
@@ -417,7 +418,10 @@ InitBuildState(HnswBuildState * buildstate, Relation heap, Relation index, Index
 
 	buildstate->m = HnswGetM(index);
 	buildstate->efConstruction = HnswGetEfConstruction(index);
-	buildstate->dimensions = TupleDescAttr(index->rd_att, 0)->atttypmod;
+	buildstate->dimensions = HnswGetDimensions(index);
+
+	if (buildstate->dimensions < 0)
+		buildstate->dimensions = TupleDescAttr(index->rd_att, 0)->atttypmod;
 
 	/* Require column to have dimensions to be indexed */
 	if (buildstate->dimensions < 0)

src/hnswutils.c

@@ -35,6 +35,20 @@ HnswGetEfConstruction(Relation index)
 	return HNSW_DEFAULT_EF_CONSTRUCTION;
 }
 
+/*
+ * Get the number of dimensions in the index
+ */
+int
+HnswGetDimensions(Relation index)
+{
+	HnswOptions *opts = (HnswOptions *) index->rd_options;
+
+	if (opts)
+		return opts->dimensions;
+
+	return HNSW_DEFAULT_DIMENSIONS;
+}
+
 /*
  * Get proc
  */