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Added l2_normalize function for sparsevec

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This commit is contained in:
Andrew Kane
2024-04-15 14:05:18 -07:00
parent 10dacfd991
commit 127ecdd650
8 changed files with 89 additions and 14 deletions
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1
README.md
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@@ -952,6 +952,7 @@ inner_product(sparsevec, sparsevec) → double precision | inner product | unrel
l1_distance(sparsevec, sparsevec) → double precision | taxicab distance | unreleased
l2_distance(sparsevec, sparsevec) → double precision | Euclidean distance | unreleased
l2_norm(sparsevec) → double precision | Euclidean norm | unreleased
l2_normalize(sparsevec) → sparsevec | Normalize with Euclidean norm | unreleased
## Installation Notes - Linux and Mac

3
sql/vector--0.6.2--0.7.0.sql
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@@ -364,6 +364,9 @@ CREATE FUNCTION l1_distance(sparsevec, sparsevec) RETURNS float8
CREATE FUNCTION l2_norm(sparsevec) RETURNS float8
AS 'MODULE_PATHNAME', 'sparsevec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
CREATE FUNCTION l2_normalize(sparsevec) RETURNS sparsevec
AS 'MODULE_PATHNAME', 'sparsevec_l2_normalize' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
CREATE FUNCTION sparsevec_lt(sparsevec, sparsevec) RETURNS bool
AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;

3
sql/vector.sql
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@@ -673,6 +673,9 @@ CREATE FUNCTION l1_distance(sparsevec, sparsevec) RETURNS float8
CREATE FUNCTION l2_norm(sparsevec) RETURNS float8
AS 'MODULE_PATHNAME', 'sparsevec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
CREATE FUNCTION l2_normalize(sparsevec) RETURNS sparsevec
AS 'MODULE_PATHNAME', 'sparsevec_l2_normalize' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
-- sparsevec private functions
CREATE FUNCTION sparsevec_lt(sparsevec, sparsevec) RETURNS bool

15
src/hnswutils.c
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@@ -213,20 +213,7 @@ HnswNormValue(FmgrInfo *procinfo, Oid collation, Datum *value, HnswType type)
else if (type == HNSW_TYPE_HALFVEC)
*value = DirectFunctionCall1(halfvec_l2_normalize, *value);
else if (type == HNSW_TYPE_SPARSEVEC)
{
SparseVector *v = DatumGetSparseVector(*value);
SparseVector *result = InitSparseVector(v->dim, v->nnz);
float *vx = SPARSEVEC_VALUES(v);
float *rx = SPARSEVEC_VALUES(result);
for (int i = 0; i < v->nnz; i++)
{
result->indices[i] = v->indices[i];
rx[i] = vx[i] / norm;
}
*value = PointerGetDatum(result);
}
*value = DirectFunctionCall1(sparsevec_l2_normalize, *value);
else
elog(ERROR, "Unsupported type");

42
src/sparsevec.c
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@@ -848,6 +848,48 @@ sparsevec_l2_norm(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(sqrt(norm));
}
/*
* Normalize a sparse vector with the L2 norm
*/
PGDLLEXPORT PG_FUNCTION_INFO_V1(sparsevec_l2_normalize);
Datum
sparsevec_l2_normalize(PG_FUNCTION_ARGS)
{
SparseVector *a = PG_GETARG_SPARSEVEC_P(0);
float *ax = SPARSEVEC_VALUES(a);
double norm = 0;
SparseVector *result;
float *rx;
result = InitSparseVector(a->dim, a->nnz);
rx = SPARSEVEC_VALUES(result);
/* Auto-vectorized */
for (int i = 0; i < a->nnz; i++)
norm += (double) ax[i] * (double) ax[i];
norm = sqrt(norm);
/* Return zero vector for zero norm */
if (norm > 0)
{
for (int i = 0; i < a->nnz; i++)
{
result->indices[i] = a->indices[i];
rx[i] = ax[i] / norm;
}
/* Check for overflow */
for (int i = 0; i < a->nnz; i++)
{
if (isinf(rx[i]))
float_overflow_error();
}
}
PG_RETURN_POINTER(result);
}
/*
* Internal helper to compare sparse vectors
*/

3
src/sparsevec.h
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@@ -1,6 +1,8 @@
#ifndef SPARSEVEC_H
#define SPARSEVEC_H
#include "fmgr.h"
#define SPARSEVEC_MAX_DIM 100000
#define SPARSEVEC_MAX_NNZ 16000
@@ -21,5 +23,6 @@ typedef struct SparseVector
} SparseVector;
SparseVector *InitSparseVector(int dim, int nnz);
Datum sparsevec_l2_normalize(PG_FUNCTION_ARGS);
#endif

30
test/expected/sparsevec_functions.out
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@@ -292,3 +292,33 @@ SELECT l1_distance('{1:1,3:3,5:5,7:7,9:9}/9'::sparsevec, '{2:2,4:4,6:6,8:8}/9');
45
(1 row)
SELECT l2_normalize('{1:3,2:4}/2'::sparsevec);
l2_normalize
-----------------
{1:0.6,2:0.8}/2
(1 row)
SELECT l2_normalize('{1:3}/2'::sparsevec);
l2_normalize
--------------
{1:1}/2
(1 row)
SELECT l2_normalize('{2:0.1}/2'::sparsevec);
l2_normalize
--------------
{2:1}/2
(1 row)
SELECT l2_normalize('{}/2'::sparsevec);
l2_normalize
--------------
{}/2
(1 row)
SELECT l2_normalize('{1:3e38}/1'::sparsevec);
l2_normalize
--------------
{1:1}/1
(1 row)

6
test/sql/sparsevec_functions.sql
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@@ -55,3 +55,9 @@ SELECT l1_distance('{1:1,2:2}/2'::sparsevec, '{1:3}/1');
SELECT l1_distance('{1:3e38}/1'::sparsevec, '{1:-3e38}/1');
SELECT l1_distance('{1:1,3:3,5:5,7:7}/8'::sparsevec, '{2:2,4:4,6:6,8:8}/8');
SELECT l1_distance('{1:1,3:3,5:5,7:7,9:9}/9'::sparsevec, '{2:2,4:4,6:6,8:8}/9');
SELECT l2_normalize('{1:3,2:4}/2'::sparsevec);
SELECT l2_normalize('{1:3}/2'::sparsevec);
SELECT l2_normalize('{2:0.1}/2'::sparsevec);
SELECT l2_normalize('{}/2'::sparsevec);
SELECT l2_normalize('{1:3e38}/1'::sparsevec);