Use integer[] for consistency [skip ci]

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 0.8.0 (unreleased)
 
 - Added support for iterative index scans
+- Added `intvec` type
 - Added casts for arrays to `sparsevec`
 - Improved cost estimation
 - Improved performance of HNSW inserts and on-disk index builds

Makefile

@@ -4,8 +4,8 @@ EXTVERSION = 0.7.4
 MODULE_big = vector
 DATA = $(wildcard sql/*--*--*.sql)
 DATA_built = sql/$(EXTENSION)--$(EXTVERSION).sql
-OBJS = src/bitutils.o src/bitvec.o src/halfutils.o src/halfvec.o src/hnsw.o src/hnswbuild.o src/hnswinsert.o src/hnswscan.o src/hnswutils.o src/hnswvacuum.o src/ivfbuild.o src/ivfflat.o src/ivfinsert.o src/ivfkmeans.o src/ivfscan.o src/ivfutils.o src/ivfvacuum.o src/sparsevec.o src/vector.o
+OBJS = src/bitutils.o src/bitvec.o src/halfutils.o src/halfvec.o src/hnsw.o src/hnswbuild.o src/hnswinsert.o src/hnswscan.o src/hnswutils.o src/hnswvacuum.o src/intvec.o src/ivfbuild.o src/ivfflat.o src/ivfinsert.o src/ivfkmeans.o src/ivfscan.o src/ivfutils.o src/ivfvacuum.o src/sparsevec.o src/vector.o
-HEADERS = src/halfvec.h src/sparsevec.h src/vector.h
+HEADERS = src/halfvec.h src/intvec.h src/sparsevec.h src/vector.h
 
 TESTS = $(wildcard test/sql/*.sql)
 REGRESS = $(patsubst test/sql/%.sql,%,$(TESTS))

Makefile.win

@@ -2,8 +2,8 @@ EXTENSION = vector
 EXTVERSION = 0.7.4
 
 DATA_built = sql\$(EXTENSION)--$(EXTVERSION).sql
-OBJS = src\bitutils.obj src\bitvec.obj src\halfutils.obj src\halfvec.obj src\hnsw.obj src\hnswbuild.obj src\hnswinsert.obj src\hnswscan.obj src\hnswutils.obj src\hnswvacuum.obj src\ivfbuild.obj src\ivfflat.obj src\ivfinsert.obj src\ivfkmeans.obj src\ivfscan.obj src\ivfutils.obj src\ivfvacuum.obj src\sparsevec.obj src\vector.obj
+OBJS = src\bitutils.obj src\bitvec.obj src\halfutils.obj src\halfvec.obj src\hnsw.obj src\hnswbuild.obj src\hnswinsert.obj src\hnswscan.obj src\hnswutils.obj src\hnswvacuum.obj src\intvec.obj src\ivfbuild.obj src\ivfflat.obj src\ivfinsert.obj src\ivfkmeans.obj src\ivfscan.obj src\ivfutils.obj src\ivfvacuum.obj src\sparsevec.obj src\vector.obj
-HEADERS = src\halfvec.h src\sparsevec.h src\vector.h
+HEADERS = src\halfvec.h src\intvec.h src\sparsevec.h src\vector.h
 
 REGRESS = bit btree cast copy halfvec hnsw_bit hnsw_halfvec hnsw_sparsevec hnsw_vector ivfflat_bit ivfflat_halfvec ivfflat_vector sparsevec vector_type
 REGRESS_OPTS = --inputdir=test --load-extension=$(EXTENSION)

README.md

@@ -223,7 +223,7 @@ L2 distance
 CREATE INDEX ON items USING hnsw (embedding vector_l2_ops);
 ```
 
-Note: Use `halfvec_l2_ops` for `halfvec` and `sparsevec_l2_ops` for `sparsevec` (and similar with the other distance functions)
+Note: Use `halfvec_l2_ops` for `halfvec`, `intvec_l2_ops` for `intvec`, and `sparsevec_l2_ops` for `sparsevec` (and similar with the other distance functions)
 
 Inner product
 
@@ -259,6 +259,7 @@ Supported types are:
 
 - `vector` - up to 2,000 dimensions
 - `halfvec` - up to 4,000 dimensions (added in 0.7.0)
+- `intvec` - up to 8,000 dimensions (added in 0.8.0)
 - `bit` - up to 64,000 dimensions (added in 0.7.0)
 - `sparsevec` - up to 1,000 non-zero elements (added in 0.7.0)
 
@@ -477,6 +478,16 @@ Get the nearest neighbors
 SELECT * FROM items ORDER BY embedding::halfvec(3) <-> '[1,2,3]' LIMIT 5;
 ```
 
+## Integer Vectors
+
+*Added in 0.8.0*
+
+Use the `intvec` type to store 8-bit integer vectors
+
+```sql
+CREATE TABLE items (id bigserial PRIMARY KEY, embedding intvec(3));
+```
+
 ## Binary Vectors
 
 Use the `bit` type to store binary vectors ([example](https://github.com/pgvector/pgvector-python/blob/master/examples/imagehash/example.py))
@@ -940,6 +951,30 @@ Function | Description | Added
 avg(halfvec) → halfvec | average | 0.7.0
 sum(halfvec) → halfvec | sum | 0.7.0
 
+### Intvec Type
+
+Each int vector takes `dimensions + 8` bytes of storage. Each element is a single byte signed integer. Int vectors can have up to 16,000 dimensions.
+
+### Intvec Operators
+
+Operator | Description | Added
+--- | --- | ---
+<-> | Euclidean distance | 0.8.0
+<#> | negative inner product | 0.8.0
+<=> | cosine distance | 0.8.0
+<+> | taxicab distance | 0.8.0
+
+### Intvec Functions
+
+Function | Description | Added
+--- | --- | ---
+cosine_distance(intvec, intvec) → double precision | cosine distance | 0.8.0
+inner_product(intvec, intvec) → double precision | inner product | 0.8.0
+l1_distance(intvec, intvec) → double precision | taxicab distance | 0.8.0
+l2_distance(intvec, intvec) → double precision | Euclidean distance | 0.8.0
+l2_norm(intvec) → double precision | Euclidean norm | 0.8.0
+vector_dims(intvec) → integer | number of dimensions | 0.8.0
+
 ### Bit Type
 
 Each bit vector takes `dimensions / 8 + 8` bytes of storage. See the [Postgres docs](https://www.postgresql.org/docs/current/datatype-bit.html) for more info.

sql/vector--0.7.4--0.8.0.sql

@@ -1,6 +1,188 @@
 -- complain if script is sourced in psql, rather than via CREATE EXTENSION
 \echo Use "ALTER EXTENSION vector UPDATE TO '0.8.0'" to load this file. \quit
 
+CREATE FUNCTION hnsw_intvec_support(internal) RETURNS internal
+	AS 'MODULE_PATHNAME' LANGUAGE C;
+
+CREATE TYPE intvec;
+
+CREATE FUNCTION intvec_in(cstring, oid, integer) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_out(intvec) RETURNS cstring
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_typmod_in(cstring[]) RETURNS integer
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_recv(internal, oid, integer) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_send(intvec) RETURNS bytea
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE TYPE intvec (
+	INPUT     = intvec_in,
+	OUTPUT    = intvec_out,
+	TYPMOD_IN = intvec_typmod_in,
+	RECEIVE   = intvec_recv,
+	SEND      = intvec_send,
+	STORAGE   = external
+);
+
+CREATE FUNCTION l2_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_l2_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION inner_product(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_inner_product' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION cosine_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_cosine_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION l1_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_l1_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION vector_dims(intvec) RETURNS integer
+	AS 'MODULE_PATHNAME', 'intvec_vector_dims' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION l2_norm(intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_lt(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_le(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_eq(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_ne(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_ge(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_gt(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_cmp(intvec, intvec) RETURNS int4
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_l2_squared_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_negative_inner_product(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec(intvec, integer, boolean) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION array_to_intvec(integer[], integer, boolean) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_to_integer(intvec, integer, boolean) RETURNS integer[]
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE CAST (intvec AS intvec)
+	WITH FUNCTION intvec(intvec, integer, boolean) AS IMPLICIT;
+
+CREATE CAST (intvec AS integer[])
+	WITH FUNCTION intvec_to_integer(intvec, integer, boolean) AS ASSIGNMENT;
+
+CREATE CAST (integer[] AS intvec)
+	WITH FUNCTION array_to_intvec(integer[], integer, boolean) AS ASSIGNMENT;
+
+CREATE OPERATOR <-> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = l2_distance,
+	COMMUTATOR = '<->'
+);
+
+CREATE OPERATOR <#> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_negative_inner_product,
+	COMMUTATOR = '<#>'
+);
+
+CREATE OPERATOR <=> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = cosine_distance,
+	COMMUTATOR = '<=>'
+);
+
+CREATE OPERATOR <+> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = l1_distance,
+	COMMUTATOR = '<+>'
+);
+
+CREATE OPERATOR < (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_lt,
+	COMMUTATOR = > , NEGATOR = >= ,
+	RESTRICT = scalarltsel, JOIN = scalarltjoinsel
+);
+
+CREATE OPERATOR <= (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_le,
+	COMMUTATOR = >= , NEGATOR = > ,
+	RESTRICT = scalarlesel, JOIN = scalarlejoinsel
+);
+
+CREATE OPERATOR = (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_eq,
+	COMMUTATOR = = , NEGATOR = <> ,
+	RESTRICT = eqsel, JOIN = eqjoinsel
+);
+
+CREATE OPERATOR <> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_ne,
+	COMMUTATOR = <> , NEGATOR = = ,
+	RESTRICT = eqsel, JOIN = eqjoinsel
+);
+
+CREATE OPERATOR >= (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_ge,
+	COMMUTATOR = <= , NEGATOR = < ,
+	RESTRICT = scalargesel, JOIN = scalargejoinsel
+);
+
+CREATE OPERATOR > (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_gt,
+	COMMUTATOR = < , NEGATOR = <= ,
+	RESTRICT = scalargtsel, JOIN = scalargtjoinsel
+);
+
+CREATE OPERATOR CLASS intvec_ops
+	DEFAULT FOR TYPE intvec USING btree AS
+	OPERATOR 1 < ,
+	OPERATOR 2 <= ,
+	OPERATOR 3 = ,
+	OPERATOR 4 >= ,
+	OPERATOR 5 > ,
+	FUNCTION 1 intvec_cmp(intvec, intvec);
+
+CREATE OPERATOR CLASS intvec_l2_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <-> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 intvec_l2_squared_distance(intvec, intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
+CREATE OPERATOR CLASS intvec_ip_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <#> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 intvec_negative_inner_product(intvec, intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
+CREATE OPERATOR CLASS intvec_cosine_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <=> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 cosine_distance(intvec, intvec),
+	FUNCTION 2 l2_norm(intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
+CREATE OPERATOR CLASS intvec_l1_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <+> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 l1_distance(intvec, intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
 CREATE FUNCTION array_to_sparsevec(integer[], integer, boolean) RETURNS sparsevec
 	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 

sql/vector.sql

@@ -272,6 +272,9 @@ CREATE FUNCTION ivfflat_bit_support(internal) RETURNS internal
 CREATE FUNCTION hnsw_halfvec_support(internal) RETURNS internal
 	AS 'MODULE_PATHNAME' LANGUAGE C;
 
+CREATE FUNCTION hnsw_intvec_support(internal) RETURNS internal
+	AS 'MODULE_PATHNAME' LANGUAGE C;
+
 CREATE FUNCTION hnsw_bit_support(internal) RETURNS internal
 	AS 'MODULE_PATHNAME' LANGUAGE C;
 
@@ -647,6 +650,199 @@ CREATE OPERATOR CLASS halfvec_l1_ops
 	FUNCTION 1 l1_distance(halfvec, halfvec),
 	FUNCTION 3 hnsw_halfvec_support(internal);
 
+-- intvec type
+
+CREATE TYPE intvec;
+
+CREATE FUNCTION intvec_in(cstring, oid, integer) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_out(intvec) RETURNS cstring
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_typmod_in(cstring[]) RETURNS integer
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_recv(internal, oid, integer) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_send(intvec) RETURNS bytea
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE TYPE intvec (
+	INPUT     = intvec_in,
+	OUTPUT    = intvec_out,
+	TYPMOD_IN = intvec_typmod_in,
+	RECEIVE   = intvec_recv,
+	SEND      = intvec_send,
+	STORAGE   = external
+);
+
+-- intvec functions
+
+CREATE FUNCTION l2_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_l2_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION inner_product(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_inner_product' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION cosine_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_cosine_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION l1_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_l1_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION vector_dims(intvec) RETURNS integer
+	AS 'MODULE_PATHNAME', 'intvec_vector_dims' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION l2_norm(intvec) RETURNS float8
+	AS 'MODULE_PATHNAME', 'intvec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+-- intvec private functions
+
+CREATE FUNCTION intvec_lt(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_le(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_eq(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_ne(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_ge(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_gt(intvec, intvec) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_cmp(intvec, intvec) RETURNS int4
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_l2_squared_distance(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_negative_inner_product(intvec, intvec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+-- intvec cast functions
+
+CREATE FUNCTION intvec(intvec, integer, boolean) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION array_to_intvec(integer[], integer, boolean) RETURNS intvec
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION intvec_to_integer(intvec, integer, boolean) RETURNS integer[]
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+-- intvec casts
+
+CREATE CAST (intvec AS intvec)
+	WITH FUNCTION intvec(intvec, integer, boolean) AS IMPLICIT;
+
+CREATE CAST (intvec AS integer[])
+	WITH FUNCTION intvec_to_integer(intvec, integer, boolean) AS ASSIGNMENT;
+
+CREATE CAST (integer[] AS intvec)
+	WITH FUNCTION array_to_intvec(integer[], integer, boolean) AS ASSIGNMENT;
+
+-- intvec operators
+
+CREATE OPERATOR <-> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = l2_distance,
+	COMMUTATOR = '<->'
+);
+
+CREATE OPERATOR <#> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_negative_inner_product,
+	COMMUTATOR = '<#>'
+);
+
+CREATE OPERATOR <=> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = cosine_distance,
+	COMMUTATOR = '<=>'
+);
+
+CREATE OPERATOR <+> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = l1_distance,
+	COMMUTATOR = '<+>'
+);
+
+CREATE OPERATOR < (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_lt,
+	COMMUTATOR = > , NEGATOR = >= ,
+	RESTRICT = scalarltsel, JOIN = scalarltjoinsel
+);
+
+CREATE OPERATOR <= (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_le,
+	COMMUTATOR = >= , NEGATOR = > ,
+	RESTRICT = scalarlesel, JOIN = scalarlejoinsel
+);
+
+CREATE OPERATOR = (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_eq,
+	COMMUTATOR = = , NEGATOR = <> ,
+	RESTRICT = eqsel, JOIN = eqjoinsel
+);
+
+CREATE OPERATOR <> (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_ne,
+	COMMUTATOR = <> , NEGATOR = = ,
+	RESTRICT = eqsel, JOIN = eqjoinsel
+);
+
+CREATE OPERATOR >= (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_ge,
+	COMMUTATOR = <= , NEGATOR = < ,
+	RESTRICT = scalargesel, JOIN = scalargejoinsel
+);
+
+CREATE OPERATOR > (
+	LEFTARG = intvec, RIGHTARG = intvec, PROCEDURE = intvec_gt,
+	COMMUTATOR = < , NEGATOR = <= ,
+	RESTRICT = scalargtsel, JOIN = scalargtjoinsel
+);
+
+-- intvec opclasses
+
+CREATE OPERATOR CLASS intvec_ops
+	DEFAULT FOR TYPE intvec USING btree AS
+	OPERATOR 1 < ,
+	OPERATOR 2 <= ,
+	OPERATOR 3 = ,
+	OPERATOR 4 >= ,
+	OPERATOR 5 > ,
+	FUNCTION 1 intvec_cmp(intvec, intvec);
+
+CREATE OPERATOR CLASS intvec_l2_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <-> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 intvec_l2_squared_distance(intvec, intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
+CREATE OPERATOR CLASS intvec_ip_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <#> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 intvec_negative_inner_product(intvec, intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
+CREATE OPERATOR CLASS intvec_cosine_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <=> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 cosine_distance(intvec, intvec),
+	FUNCTION 2 l2_norm(intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
+CREATE OPERATOR CLASS intvec_l1_ops
+	FOR TYPE intvec USING hnsw AS
+	OPERATOR 1 <+> (intvec, intvec) FOR ORDER BY float_ops,
+	FUNCTION 1 l1_distance(intvec, intvec),
+	FUNCTION 3 hnsw_intvec_support(internal);
+
 -- bit functions
 
 CREATE FUNCTION hamming_distance(bit, bit) RETURNS float8

src/hnswutils.c

@@ -1,5 +1,6 @@
 #include "postgres.h"
 
+#include <float.h>
 #include <math.h>
 
 #include "access/generic_xlog.h"
@@ -157,6 +158,9 @@ HnswInitSupport(HnswSupport * support, Relation index)
 Datum
 HnswNormValue(const HnswTypeInfo * typeInfo, Oid collation, Datum value)
 {
+	if (!typeInfo->normalize)
+		return value;
+
 	return DirectFunctionCall1Coll(typeInfo->normalize, collation, value);
 }
 
@@ -546,7 +550,14 @@ HnswLoadElementImpl(BlockNumber blkno, OffsetNumber offno, double *distance, Hns
 		if (DatumGetPointer(q->value) == NULL)
 			*distance = 0;
 		else
+		{
 			*distance = HnswGetDistance(q->value, PointerGetDatum(&etup->data), support);
+
+			/* Needed for intvec cosine distance */
+			/* TODO Improve */
+			if (isnan(*distance))
+				*distance = DBL_MAX;
+		}
 	}
 
 	/* Load element */
@@ -1393,6 +1404,19 @@ hnsw_halfvec_support(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(&typeInfo);
 };
 
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(hnsw_intvec_support);
+Datum
+hnsw_intvec_support(PG_FUNCTION_ARGS)
+{
+	static const HnswTypeInfo typeInfo = {
+		.maxDimensions = HNSW_MAX_DIM * 4,
+		.normalize = NULL,
+		.checkValue = NULL
+	};
+
+	PG_RETURN_POINTER(&typeInfo);
+};
+
 FUNCTION_PREFIX PG_FUNCTION_INFO_V1(hnsw_bit_support);
 Datum
 hnsw_bit_support(PG_FUNCTION_ARGS)

src/intvec.c

@@ -0,0 +1,754 @@
+#include "postgres.h"
+
+#include <limits.h>
+#include <math.h>
+
+#include "catalog/pg_type.h"
+#include "fmgr.h"
+#include "intvec.h"
+#include "lib/stringinfo.h"
+#include "libpq/pqformat.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+/*
+ * Ensure same dimensions
+ */
+static inline void
+CheckDims(IntVector * a, IntVector * b)
+{
+	if (a->dim != b->dim)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("different intvec dimensions %d and %d", a->dim, b->dim)));
+}
+
+/*
+ * Ensure expected dimensions
+ */
+static inline void
+CheckExpectedDim(int32 typmod, int dim)
+{
+	if (typmod != -1 && typmod != dim)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("expected %d dimensions, not %d", typmod, dim)));
+}
+
+/*
+ * Ensure valid dimensions
+ */
+static inline void
+CheckDim(int dim)
+{
+	if (dim < 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("intvec must have at least 1 dimension")));
+
+	if (dim > INTVEC_MAX_DIM)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("intvec cannot have more than %d dimensions", INTVEC_MAX_DIM)));
+}
+
+/*
+ * Ensure element in range
+ */
+static inline void
+CheckElement(long value)
+{
+	if (value < SCHAR_MIN || value > SCHAR_MAX)
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("value \"%ld\" is out of range for type intvec", value)));
+}
+
+/*
+ * Allocate and initialize a new int vector
+ */
+IntVector *
+InitIntVector(int dim)
+{
+	IntVector  *result;
+	int			size;
+
+	size = INTVEC_SIZE(dim);
+	result = (IntVector *) palloc0(size);
+	SET_VARSIZE(result, size);
+	result->dim = dim;
+
+	return result;
+}
+
+/*
+ * Check for whitespace, since array_isspace() is static
+ */
+static inline bool
+intvec_isspace(char ch)
+{
+	if (ch == ' ' ||
+		ch == '\t' ||
+		ch == '\n' ||
+		ch == '\r' ||
+		ch == '\v' ||
+		ch == '\f')
+		return true;
+	return false;
+}
+
+/*
+ * Convert textual representation to internal representation
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_in);
+Datum
+intvec_in(PG_FUNCTION_ARGS)
+{
+	char	   *lit = PG_GETARG_CSTRING(0);
+	int32		typmod = PG_GETARG_INT32(2);
+	int8		x[INTVEC_MAX_DIM];
+	int			dim = 0;
+	char	   *pt = lit;
+	IntVector  *result;
+
+	while (intvec_isspace(*pt))
+		pt++;
+
+	if (*pt != '[')
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input syntax for type intvec: \"%s\"", lit),
+				 errdetail("Vector contents must start with \"[\".")));
+
+	pt++;
+
+	while (intvec_isspace(*pt))
+		pt++;
+
+	if (*pt == ']')
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("intvec must have at least 1 dimension")));
+
+	for (;;)
+	{
+		long		val;
+		char	   *stringEnd;
+
+		if (dim == INTVEC_MAX_DIM)
+			ereport(ERROR,
+					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+					 errmsg("intvec cannot have more than %d dimensions", VECTOR_MAX_DIM)));
+
+		while (intvec_isspace(*pt))
+			pt++;
+
+		/* Check for empty string like float4in */
+		if (*pt == '\0')
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for type intvec: \"%s\"", lit)));
+
+		errno = 0;
+
+		/* Use similar logic as int2vectorin */
+		val = strtol(pt, &stringEnd, 10);
+
+		if (stringEnd == pt)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for type intvec: \"%s\"", lit)));
+
+		/* Check for range error like float4in */
+		if (errno == ERANGE || val < SCHAR_MIN || val > SCHAR_MAX)
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("\"%s\" is out of range for type intvec", pnstrdup(pt, stringEnd - pt))));
+
+		CheckElement(val);
+		x[dim++] = val;
+
+		pt = stringEnd;
+
+		while (intvec_isspace(*pt))
+			pt++;
+
+		if (*pt == ',')
+			pt++;
+		else if (*pt == ']')
+		{
+			pt++;
+			break;
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for type intvec: \"%s\"", lit)));
+	}
+
+	/* Only whitespace is allowed after the closing brace */
+	while (intvec_isspace(*pt))
+		pt++;
+
+	if (*pt != '\0')
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input syntax for type intvec: \"%s\"", lit),
+				 errdetail("Junk after closing right brace.")));
+
+	CheckDim(dim);
+	CheckExpectedDim(typmod, dim);
+
+	result = InitIntVector(dim);
+	for (int i = 0; i < dim; i++)
+		result->x[i] = x[i];
+
+	PG_RETURN_POINTER(result);
+}
+
+/*
+ * Convert internal representation to textual representation
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_out);
+Datum
+intvec_out(PG_FUNCTION_ARGS)
+{
+	IntVector  *vector = PG_GETARG_INTVEC_P(0);
+	int			dim = vector->dim;
+	char	   *buf;
+	char	   *ptr;
+
+	/*
+	 * Need:
+	 *
+	 * dim * 4 bytes for elements (-128 to 127)
+	 *
+	 * dim - 1 bytes for separator
+	 *
+	 * 3 bytes for [, ], and \0
+	 */
+	buf = (char *) palloc(5 * dim + 2);
+	ptr = buf;
+
+	*ptr = '[';
+	ptr++;
+	for (int i = 0; i < dim; i++)
+	{
+		if (i > 0)
+		{
+			*ptr = ',';
+			ptr++;
+		}
+
+#if PG_VERSION_NUM >= 140000
+		ptr += pg_ltoa(vector->x[i], ptr);
+#else
+		pg_ltoa(vector->x[i], ptr);
+		while (*ptr != '\0')
+			ptr++;
+#endif
+	}
+	*ptr = ']';
+	ptr++;
+	*ptr = '\0';
+
+	PG_FREE_IF_COPY(vector, 0);
+	PG_RETURN_CSTRING(buf);
+}
+
+/*
+ * Convert type modifier
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_typmod_in);
+Datum
+intvec_typmod_in(PG_FUNCTION_ARGS)
+{
+	ArrayType  *ta = PG_GETARG_ARRAYTYPE_P(0);
+	int32	   *tl;
+	int			n;
+
+	tl = ArrayGetIntegerTypmods(ta, &n);
+
+	if (n != 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid type modifier")));
+
+	if (*tl < 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("dimensions for type intvec must be at least 1")));
+
+	if (*tl > INTVEC_MAX_DIM)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("dimensions for type intvec cannot exceed %d", INTVEC_MAX_DIM)));
+
+	PG_RETURN_INT32(*tl);
+}
+
+/*
+ * Convert external binary representation to internal representation
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_recv);
+Datum
+intvec_recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	int32		typmod = PG_GETARG_INT32(2);
+	IntVector  *result;
+	int16		dim;
+	int16		unused;
+
+	dim = pq_getmsgint(buf, sizeof(int16));
+	unused = pq_getmsgint(buf, sizeof(int16));
+
+	CheckDim(dim);
+	CheckExpectedDim(typmod, dim);
+
+	if (unused != 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("expected unused to be 0, not %d", unused)));
+
+	result = InitIntVector(dim);
+	for (int i = 0; i < dim; i++)
+		result->x[i] = pq_getmsgint(buf, sizeof(int8));
+
+	PG_RETURN_POINTER(result);
+}
+
+/*
+ * Convert internal representation to the external binary representation
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_send);
+Datum
+intvec_send(PG_FUNCTION_ARGS)
+{
+	IntVector  *vec = PG_GETARG_INTVEC_P(0);
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendint(&buf, vec->dim, sizeof(int16));
+	pq_sendint(&buf, vec->unused, sizeof(int16));
+	for (int i = 0; i < vec->dim; i++)
+		pq_sendint8(&buf, vec->x[i]);
+
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+/*
+ * Convert int vector to int vector
+ * This is needed to check the type modifier
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec);
+Datum
+intvec(PG_FUNCTION_ARGS)
+{
+	IntVector  *vec = PG_GETARG_INTVEC_P(0);
+	int32		typmod = PG_GETARG_INT32(1);
+
+	CheckExpectedDim(typmod, vec->dim);
+
+	PG_RETURN_POINTER(vec);
+}
+
+/*
+ * Convert array to intvec vector
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(array_to_intvec);
+Datum
+array_to_intvec(PG_FUNCTION_ARGS)
+{
+	ArrayType  *array = PG_GETARG_ARRAYTYPE_P(0);
+	int32		typmod = PG_GETARG_INT32(1);
+	IntVector  *result;
+	int16		typlen;
+	bool		typbyval;
+	char		typalign;
+	Datum	   *elemsp;
+	int			nelemsp;
+
+	if (ARR_NDIM(array) > 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("array must be 1-D")));
+
+	if (ARR_HASNULL(array) && array_contains_nulls(array))
+		ereport(ERROR,
+				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+				 errmsg("array must not contain nulls")));
+
+	get_typlenbyvalalign(ARR_ELEMTYPE(array), &typlen, &typbyval, &typalign);
+	deconstruct_array(array, ARR_ELEMTYPE(array), typlen, typbyval, typalign, &elemsp, NULL, &nelemsp);
+
+	CheckDim(nelemsp);
+	CheckExpectedDim(typmod, nelemsp);
+
+	result = InitIntVector(nelemsp);
+
+	if (ARR_ELEMTYPE(array) == INT4OID)
+	{
+		for (int i = 0; i < nelemsp; i++)
+		{
+			long		l = DatumGetInt32(elemsp[i]);
+
+			CheckElement(l);
+
+			result->x[i] = l;
+		}
+	}
+	else
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("unsupported array type")));
+	}
+
+	/*
+	 * Free allocation from deconstruct_array. Do not free individual elements
+	 * when pass-by-reference since they point to original array.
+	 */
+	pfree(elemsp);
+
+	PG_RETURN_POINTER(result);
+}
+
+/*
+ * Convert int vector to integer[]
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_to_integer);
+Datum
+intvec_to_integer(PG_FUNCTION_ARGS)
+{
+	IntVector  *vec = PG_GETARG_INTVEC_P(0);
+	Datum	   *datums;
+	ArrayType  *result;
+
+	datums = (Datum *) palloc(sizeof(Datum) * vec->dim);
+
+	for (int i = 0; i < vec->dim; i++)
+		datums[i] = Int32GetDatum((int) vec->x[i]);
+
+	result = construct_array(datums, vec->dim, INT4OID, sizeof(int32), true, TYPALIGN_INT);
+
+	pfree(datums);
+
+	PG_RETURN_POINTER(result);
+}
+
+static int
+IntvecL2SquaredDistance(int dim, int8 *ax, int8 *bx)
+{
+	int			distance = 0;
+
+	/* Auto-vectorized */
+	for (int i = 0; i < dim; i++)
+	{
+		int			diff = (int) ax[i] - (int) bx[i];
+
+		distance += diff * diff;
+	}
+
+	return distance;
+}
+
+/*
+ * Get the L2 distance between int vectors
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_l2_distance);
+Datum
+intvec_l2_distance(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	CheckDims(a, b);
+
+	PG_RETURN_FLOAT8(sqrt((double) IntvecL2SquaredDistance(a->dim, a->x, b->x)));
+}
+
+/*
+ * Get the L2 squared distance between int vectors
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_l2_squared_distance);
+Datum
+intvec_l2_squared_distance(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	CheckDims(a, b);
+
+	PG_RETURN_FLOAT8((double) IntvecL2SquaredDistance(a->dim, a->x, b->x));
+}
+
+static int
+IntvecInnerProduct(int dim, int8 *ax, int8 *bx)
+{
+	int			distance = 0;
+
+	/* Auto-vectorized */
+	for (int i = 0; i < dim; i++)
+		distance += (int) ax[i] * (int) bx[i];
+
+	return distance;
+}
+
+/*
+ * Get the inner product of two int vectors
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_inner_product);
+Datum
+intvec_inner_product(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	CheckDims(a, b);
+
+	PG_RETURN_FLOAT8((double) IntvecInnerProduct(a->dim, a->x, b->x));
+}
+
+/*
+ * Get the negative inner product of two int vectors
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_negative_inner_product);
+Datum
+intvec_negative_inner_product(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	CheckDims(a, b);
+
+	PG_RETURN_FLOAT8((double) -IntvecInnerProduct(a->dim, a->x, b->x));
+}
+
+static double
+IntvecCosineSimilarity(int dim, int8 *ax, int8 *bx)
+{
+	int			similarity = 0;
+	int			norma = 0;
+	int			normb = 0;
+
+	/* Auto-vectorized */
+	for (int i = 0; i < dim; i++)
+	{
+		int			axi = ax[i];
+		int			bxi = bx[i];
+
+		similarity += axi * bxi;
+		norma += axi * axi;
+		normb += bxi * bxi;
+	}
+
+	/* Use sqrt(a * b) over sqrt(a) * sqrt(b) */
+	return (double) similarity / sqrt((double) norma * (double) normb);
+}
+
+/*
+ * Get the cosine distance between two int vectors
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_cosine_distance);
+Datum
+intvec_cosine_distance(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+	double		similarity;
+
+	CheckDims(a, b);
+
+	similarity = IntvecCosineSimilarity(a->dim, a->x, b->x);
+
+#ifdef _MSC_VER
+	/* /fp:fast may not propagate NaN */
+	if (isnan(similarity))
+		PG_RETURN_FLOAT8(NAN);
+#endif
+
+	/* Keep in range */
+	if (similarity > 1)
+		similarity = 1;
+	else if (similarity < -1)
+		similarity = -1;
+
+	PG_RETURN_FLOAT8(1 - similarity);
+}
+
+static int
+IntvecL1Distance(int dim, int8 *ax, int8 *bx)
+{
+	int			distance = 0;
+
+	/* Auto-vectorized */
+	for (int i = 0; i < dim; i++)
+		distance += abs((int) ax[i] - (int) bx[i]);
+
+	return distance;
+}
+
+/*
+ * Get the L1 distance between two int vectors
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_l1_distance);
+Datum
+intvec_l1_distance(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	CheckDims(a, b);
+
+	PG_RETURN_FLOAT8((double) IntvecL1Distance(a->dim, a->x, b->x));
+}
+
+/*
+ * Get the dimensions of an int vector
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_vector_dims);
+Datum
+intvec_vector_dims(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+
+	PG_RETURN_INT32(a->dim);
+}
+
+/*
+ * Get the L2 norm of an int vector
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(intvec_l2_norm);
+Datum
+intvec_l2_norm(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	int8	   *ax = a->x;
+	int			norm = 0;
+
+	/* Auto-vectorized */
+	for (int i = 0; i < a->dim; i++)
+		norm += (int) ax[i] * (int) ax[i];
+
+	PG_RETURN_FLOAT8(sqrt((double) norm));
+}
+
+/*
+ * Internal helper to compare int vectors
+ */
+static int
+intvec_cmp_internal(IntVector * a, IntVector * b)
+{
+	int			dim = Min(a->dim, b->dim);
+
+	/* Check values before dimensions to be consistent with Postgres arrays */
+	for (int i = 0; i < dim; i++)
+	{
+		if (a->x[i] < b->x[i])
+			return -1;
+
+		if (a->x[i] > b->x[i])
+			return 1;
+	}
+
+	if (a->dim < b->dim)
+		return -1;
+
+	if (a->dim > b->dim)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Less than
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_lt);
+Datum
+intvec_lt(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	PG_RETURN_BOOL(intvec_cmp_internal(a, b) < 0);
+}
+
+/*
+ * Less than or equal
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_le);
+Datum
+intvec_le(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	PG_RETURN_BOOL(intvec_cmp_internal(a, b) <= 0);
+}
+
+/*
+ * Equal
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_eq);
+Datum
+intvec_eq(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	PG_RETURN_BOOL(intvec_cmp_internal(a, b) == 0);
+}
+
+/*
+ * Not equal
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_ne);
+Datum
+intvec_ne(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	PG_RETURN_BOOL(intvec_cmp_internal(a, b) != 0);
+}
+
+/*
+ * Greater than or equal
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_ge);
+Datum
+intvec_ge(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	PG_RETURN_BOOL(intvec_cmp_internal(a, b) >= 0);
+}
+
+/*
+ * Greater than
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_gt);
+Datum
+intvec_gt(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	PG_RETURN_BOOL(intvec_cmp_internal(a, b) > 0);
+}
+
+/*
+ * Compare int vectors
+ */
+FUNCTION_PREFIX PG_FUNCTION_INFO_V1(intvec_cmp);
+Datum
+intvec_cmp(PG_FUNCTION_ARGS)
+{
+	IntVector  *a = PG_GETARG_INTVEC_P(0);
+	IntVector  *b = PG_GETARG_INTVEC_P(1);
+
+	PG_RETURN_INT32(intvec_cmp_internal(a, b));
+}

src/intvec.h

@@ -0,0 +1,23 @@
+#ifndef INTVEC_H
+#define INTVEC_H
+
+#include "vector.h"
+
+#define INTVEC_MAX_DIM VECTOR_MAX_DIM
+
+#define INTVEC_SIZE(_dim)		(offsetof(IntVector, x) + sizeof(int8)*(_dim))
+#define DatumGetIntVector(x)	((IntVector *) PG_DETOAST_DATUM(x))
+#define PG_GETARG_INTVEC_P(x)	DatumGetIntVector(PG_GETARG_DATUM(x))
+#define PG_RETURN_INTVEC_P(x)	PG_RETURN_POINTER(x)
+
+typedef struct IntVector
+{
+	int32		vl_len_;		/* varlena header (do not touch directly!) */
+	int16		dim;			/* number of dimensions */
+	int16		unused;
+	int8		x[FLEXIBLE_ARRAY_MEMBER];
+}			IntVector;
+
+IntVector  *InitIntVector(int dim);
+
+#endif

test/expected/cast.out

@@ -140,6 +140,34 @@ SELECT '{1e-8,-1e-8}'::real[]::halfvec;
  [0,-0]
 (1 row)
 
+SELECT '[1,2,3]'::intvec::integer[];
+  int4   
+---------
+ {1,2,3}
+(1 row)
+
+SELECT '{1,2,3}'::integer[]::intvec;
+ intvec  
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '{1,2,3}'::integer[]::intvec(3);
+ intvec  
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '{1,2,3}'::integer[]::intvec(2);
+ERROR:  expected 2 dimensions, not 3
+SELECT '{127,-128}'::integer[]::intvec;
+   intvec   
+------------
+ [127,-128]
+(1 row)
+
+SELECT '{128,-129}'::integer[]::intvec;
+ERROR:  value "128" is out of range for type intvec
 SELECT '[0,1.5,0,3.5,0]'::vector::sparsevec;
     sparsevec    
 -----------------

test/expected/copy.out

@@ -30,6 +30,23 @@ SELECT * FROM t2 ORDER BY val;
  
 (4 rows)
 
+DROP TABLE t;
+DROP TABLE t2;
+-- intvec
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE TABLE t2 (val intvec(3));
+\copy t TO 'results/intvec.bin' WITH (FORMAT binary)
+\copy t2 FROM 'results/intvec.bin' WITH (FORMAT binary)
+SELECT * FROM t2 ORDER BY val;
+   val   
+---------
+ [0,0,0]
+ [1,1,1]
+ [1,2,3]
+ 
+(4 rows)
+
 DROP TABLE t;
 DROP TABLE t2;
 -- sparsevec

test/expected/hnsw_intvec.out

@@ -0,0 +1,102 @@
+SET enable_seqscan = off;
+-- L2
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_l2_ops);
+INSERT INTO t (val) VALUES ('[1,2,4]');
+SELECT * FROM t ORDER BY val <-> '[3,3,3]';
+   val   
+---------
+ [1,2,3]
+ [1,2,4]
+ [1,1,1]
+ [0,0,0]
+(4 rows)
+
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <-> (SELECT NULL::intvec)) t2;
+ count 
+-------
+     4
+(1 row)
+
+SELECT COUNT(*) FROM t;
+ count 
+-------
+     5
+(1 row)
+
+TRUNCATE t;
+SELECT * FROM t ORDER BY val <-> '[3,3,3]';
+ val 
+-----
+(0 rows)
+
+DROP TABLE t;
+-- inner product
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_ip_ops);
+INSERT INTO t (val) VALUES ('[1,2,4]');
+SELECT * FROM t ORDER BY val <#> '[3,3,3]';
+   val   
+---------
+ [1,2,4]
+ [1,2,3]
+ [1,1,1]
+ [0,0,0]
+(4 rows)
+
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <#> (SELECT NULL::intvec)) t2;
+ count 
+-------
+     4
+(1 row)
+
+DROP TABLE t;
+-- cosine
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_cosine_ops);
+INSERT INTO t (val) VALUES ('[1,2,4]');
+SELECT * FROM t ORDER BY val <=> '[3,3,3]';
+   val   
+---------
+ [1,1,1]
+ [1,2,3]
+ [1,2,4]
+(3 rows)
+
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <=> '[0,0,0]') t2;
+ count 
+-------
+     3
+(1 row)
+
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <=> (SELECT NULL::intvec)) t2;
+ count 
+-------
+     3
+(1 row)
+
+DROP TABLE t;
+-- L1
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_l1_ops);
+INSERT INTO t (val) VALUES ('[1,2,4]');
+SELECT * FROM t ORDER BY val <+> '[3,3,3]';
+   val   
+---------
+ [1,2,3]
+ [1,2,4]
+ [1,1,1]
+ [0,0,0]
+(4 rows)
+
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <+> (SELECT NULL::intvec)) t2;
+ count 
+-------
+     4
+(1 row)
+
+DROP TABLE t;

test/expected/intvec.out

@@ -0,0 +1,328 @@
+SELECT '[1,2,3]'::intvec;
+ intvec  
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '[-1,-2,-3]'::intvec;
+   intvec   
+------------
+ [-1,-2,-3]
+(1 row)
+
+SELECT ' [ 1,  2 ,    3  ] '::intvec;
+ intvec  
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '[1.23456]'::intvec;
+ERROR:  invalid input syntax for type intvec: "[1.23456]"
+LINE 1: SELECT '[1.23456]'::intvec;
+               ^
+SELECT '[hello,1]'::intvec;
+ERROR:  invalid input syntax for type intvec: "[hello,1]"
+LINE 1: SELECT '[hello,1]'::intvec;
+               ^
+SELECT '[127,-128]'::intvec;
+   intvec   
+------------
+ [127,-128]
+(1 row)
+
+SELECT '[128,-129]'::intvec;
+ERROR:  "128" is out of range for type intvec
+LINE 1: SELECT '[128,-129]'::intvec;
+               ^
+SELECT '[1,2,3'::intvec;
+ERROR:  invalid input syntax for type intvec: "[1,2,3"
+LINE 1: SELECT '[1,2,3'::intvec;
+               ^
+SELECT '[1,2,3]9'::intvec;
+ERROR:  invalid input syntax for type intvec: "[1,2,3]9"
+LINE 1: SELECT '[1,2,3]9'::intvec;
+               ^
+DETAIL:  Junk after closing right brace.
+SELECT '1,2,3'::intvec;
+ERROR:  invalid input syntax for type intvec: "1,2,3"
+LINE 1: SELECT '1,2,3'::intvec;
+               ^
+DETAIL:  Vector contents must start with "[".
+SELECT ''::intvec;
+ERROR:  invalid input syntax for type intvec: ""
+LINE 1: SELECT ''::intvec;
+               ^
+DETAIL:  Vector contents must start with "[".
+SELECT '['::intvec;
+ERROR:  invalid input syntax for type intvec: "["
+LINE 1: SELECT '['::intvec;
+               ^
+SELECT '[,'::intvec;
+ERROR:  invalid input syntax for type intvec: "[,"
+LINE 1: SELECT '[,'::intvec;
+               ^
+SELECT '[]'::intvec;
+ERROR:  intvec must have at least 1 dimension
+LINE 1: SELECT '[]'::intvec;
+               ^
+SELECT '[1,]'::intvec;
+ERROR:  invalid input syntax for type intvec: "[1,]"
+LINE 1: SELECT '[1,]'::intvec;
+               ^
+SELECT '[1a]'::intvec;
+ERROR:  invalid input syntax for type intvec: "[1a]"
+LINE 1: SELECT '[1a]'::intvec;
+               ^
+SELECT '[1,,3]'::intvec;
+ERROR:  invalid input syntax for type intvec: "[1,,3]"
+LINE 1: SELECT '[1,,3]'::intvec;
+               ^
+SELECT '[1, ,3]'::intvec;
+ERROR:  invalid input syntax for type intvec: "[1, ,3]"
+LINE 1: SELECT '[1, ,3]'::intvec;
+               ^
+SELECT '[1,2,3]'::intvec(3);
+ intvec  
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '[1,2,3]'::intvec(2);
+ERROR:  expected 2 dimensions, not 3
+SELECT '[1,2,3]'::intvec(3, 2);
+ERROR:  invalid type modifier
+LINE 1: SELECT '[1,2,3]'::intvec(3, 2);
+                          ^
+SELECT '[1,2,3]'::intvec('a');
+ERROR:  invalid input syntax for type integer: "a"
+LINE 1: SELECT '[1,2,3]'::intvec('a');
+                          ^
+SELECT '[1,2,3]'::intvec(0);
+ERROR:  dimensions for type intvec must be at least 1
+LINE 1: SELECT '[1,2,3]'::intvec(0);
+                          ^
+SELECT '[1,2,3]'::intvec(16001);
+ERROR:  dimensions for type intvec cannot exceed 16000
+LINE 1: SELECT '[1,2,3]'::intvec(16001);
+                          ^
+SELECT unnest('{"[1,2,3]", "[4,5,6]"}'::intvec[]);
+ unnest  
+---------
+ [1,2,3]
+ [4,5,6]
+(2 rows)
+
+SELECT '{"[1,2,3]"}'::intvec(2)[];
+ERROR:  expected 2 dimensions, not 3
+SELECT '[1,2,3]'::intvec < '[1,2,3]';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT '[1,2,3]'::intvec < '[1,2]';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT '[1,2,3]'::intvec <= '[1,2,3]';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT '[1,2,3]'::intvec <= '[1,2]';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT '[1,2,3]'::intvec = '[1,2,3]';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT '[1,2,3]'::intvec = '[1,2]';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT '[1,2,3]'::intvec != '[1,2,3]';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT '[1,2,3]'::intvec != '[1,2]';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT '[1,2,3]'::intvec >= '[1,2,3]';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT '[1,2,3]'::intvec >= '[1,2]';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT '[1,2,3]'::intvec > '[1,2,3]';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT '[1,2,3]'::intvec > '[1,2]';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT intvec_cmp('[1,2,3]', '[1,2,3]');
+ intvec_cmp 
+------------
+          0
+(1 row)
+
+SELECT intvec_cmp('[1,2,3]', '[0,0,0]');
+ intvec_cmp 
+------------
+          1
+(1 row)
+
+SELECT intvec_cmp('[0,0,0]', '[1,2,3]');
+ intvec_cmp 
+------------
+         -1
+(1 row)
+
+SELECT intvec_cmp('[1,2]', '[1,2,3]');
+ intvec_cmp 
+------------
+         -1
+(1 row)
+
+SELECT intvec_cmp('[1,2,3]', '[1,2]');
+ intvec_cmp 
+------------
+          1
+(1 row)
+
+SELECT intvec_cmp('[1,2]', '[2,3,4]');
+ intvec_cmp 
+------------
+         -1
+(1 row)
+
+SELECT intvec_cmp('[2,3]', '[1,2,3]');
+ intvec_cmp 
+------------
+          1
+(1 row)
+
+SELECT vector_dims('[1,2,3]'::intvec);
+ vector_dims 
+-------------
+           3
+(1 row)
+
+SELECT l2_distance('[0,0]'::intvec, '[3,4]');
+ l2_distance 
+-------------
+           5
+(1 row)
+
+SELECT l2_distance('[0,0]'::intvec, '[0,1]');
+ l2_distance 
+-------------
+           1
+(1 row)
+
+SELECT l2_distance('[1,2]'::intvec, '[3]');
+ERROR:  different intvec dimensions 2 and 1
+SELECT '[0,0]'::intvec <-> '[3,4]';
+ ?column? 
+----------
+        5
+(1 row)
+
+SELECT inner_product('[1,2]'::intvec, '[3,4]');
+ inner_product 
+---------------
+            11
+(1 row)
+
+SELECT inner_product('[1,2]'::intvec, '[3]');
+ERROR:  different intvec dimensions 2 and 1
+SELECT inner_product('[127]'::intvec, '[127]');
+ inner_product 
+---------------
+         16129
+(1 row)
+
+SELECT '[1,2]'::intvec <#> '[3,4]';
+ ?column? 
+----------
+      -11
+(1 row)
+
+SELECT cosine_distance('[1,2]'::intvec, '[2,4]');
+ cosine_distance 
+-----------------
+               0
+(1 row)
+
+SELECT cosine_distance('[1,2]'::intvec, '[0,0]');
+ cosine_distance 
+-----------------
+             NaN
+(1 row)
+
+SELECT cosine_distance('[1,1]'::intvec, '[1,1]');
+ cosine_distance 
+-----------------
+               0
+(1 row)
+
+SELECT cosine_distance('[1,0]'::intvec, '[0,2]');
+ cosine_distance 
+-----------------
+               1
+(1 row)
+
+SELECT cosine_distance('[1,1]'::intvec, '[-1,-1]');
+ cosine_distance 
+-----------------
+               2
+(1 row)
+
+SELECT cosine_distance('[1,2]'::intvec, '[3]');
+ERROR:  different intvec dimensions 2 and 1
+SELECT '[1,2]'::intvec <=> '[2,4]';
+ ?column? 
+----------
+        0
+(1 row)
+
+SELECT l1_distance('[0,0]'::intvec, '[3,4]');
+ l1_distance 
+-------------
+           7
+(1 row)
+
+SELECT l1_distance('[0,0]'::intvec, '[0,1]');
+ l1_distance 
+-------------
+           1
+(1 row)
+
+SELECT l1_distance('[1,2]'::intvec, '[3]');
+ERROR:  different intvec dimensions 2 and 1

test/sql/cast.sql

@@ -38,6 +38,14 @@ SELECT '{1,2,3}'::real[]::halfvec(2);
 SELECT '{65520,-65520}'::real[]::halfvec;
 SELECT '{1e-8,-1e-8}'::real[]::halfvec;
 
+SELECT '[1,2,3]'::intvec::integer[];
+
+SELECT '{1,2,3}'::integer[]::intvec;
+SELECT '{1,2,3}'::integer[]::intvec(3);
+SELECT '{1,2,3}'::integer[]::intvec(2);
+SELECT '{127,-128}'::integer[]::intvec;
+SELECT '{128,-129}'::integer[]::intvec;
+
 SELECT '[0,1.5,0,3.5,0]'::vector::sparsevec;
 SELECT '[0,1.5,0,3.5,0]'::vector::sparsevec(5);
 SELECT '[0,1.5,0,3.5,0]'::vector::sparsevec(4);

test/sql/copy.sql

@@ -28,6 +28,21 @@ SELECT * FROM t2 ORDER BY val;
 DROP TABLE t;
 DROP TABLE t2;
 
+-- intvec
+
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+
+CREATE TABLE t2 (val intvec(3));
+
+\copy t TO 'results/intvec.bin' WITH (FORMAT binary)
+\copy t2 FROM 'results/intvec.bin' WITH (FORMAT binary)
+
+SELECT * FROM t2 ORDER BY val;
+
+DROP TABLE t;
+DROP TABLE t2;
+
 -- sparsevec
 
 CREATE TABLE t (val sparsevec(3));

test/sql/hnsw_intvec.sql

@@ -0,0 +1,58 @@
+SET enable_seqscan = off;
+
+-- L2
+
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_l2_ops);
+
+INSERT INTO t (val) VALUES ('[1,2,4]');
+
+SELECT * FROM t ORDER BY val <-> '[3,3,3]';
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <-> (SELECT NULL::intvec)) t2;
+SELECT COUNT(*) FROM t;
+
+TRUNCATE t;
+SELECT * FROM t ORDER BY val <-> '[3,3,3]';
+
+DROP TABLE t;
+
+-- inner product
+
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_ip_ops);
+
+INSERT INTO t (val) VALUES ('[1,2,4]');
+
+SELECT * FROM t ORDER BY val <#> '[3,3,3]';
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <#> (SELECT NULL::intvec)) t2;
+
+DROP TABLE t;
+
+-- cosine
+
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_cosine_ops);
+
+INSERT INTO t (val) VALUES ('[1,2,4]');
+
+SELECT * FROM t ORDER BY val <=> '[3,3,3]';
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <=> '[0,0,0]') t2;
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <=> (SELECT NULL::intvec)) t2;
+
+DROP TABLE t;
+
+-- L1
+
+CREATE TABLE t (val intvec(3));
+INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
+CREATE INDEX ON t USING hnsw (val intvec_l1_ops);
+
+INSERT INTO t (val) VALUES ('[1,2,4]');
+
+SELECT * FROM t ORDER BY val <+> '[3,3,3]';
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <+> (SELECT NULL::intvec)) t2;
+
+DROP TABLE t;

test/sql/intvec.sql

@@ -0,0 +1,73 @@
+SELECT '[1,2,3]'::intvec;
+SELECT '[-1,-2,-3]'::intvec;
+SELECT ' [ 1,  2 ,    3  ] '::intvec;
+SELECT '[1.23456]'::intvec;
+SELECT '[hello,1]'::intvec;
+SELECT '[127,-128]'::intvec;
+SELECT '[128,-129]'::intvec;
+SELECT '[1,2,3'::intvec;
+SELECT '[1,2,3]9'::intvec;
+SELECT '1,2,3'::intvec;
+SELECT ''::intvec;
+SELECT '['::intvec;
+SELECT '[,'::intvec;
+SELECT '[]'::intvec;
+SELECT '[1,]'::intvec;
+SELECT '[1a]'::intvec;
+SELECT '[1,,3]'::intvec;
+SELECT '[1, ,3]'::intvec;
+
+SELECT '[1,2,3]'::intvec(3);
+SELECT '[1,2,3]'::intvec(2);
+SELECT '[1,2,3]'::intvec(3, 2);
+SELECT '[1,2,3]'::intvec('a');
+SELECT '[1,2,3]'::intvec(0);
+SELECT '[1,2,3]'::intvec(16001);
+
+SELECT unnest('{"[1,2,3]", "[4,5,6]"}'::intvec[]);
+SELECT '{"[1,2,3]"}'::intvec(2)[];
+
+SELECT '[1,2,3]'::intvec < '[1,2,3]';
+SELECT '[1,2,3]'::intvec < '[1,2]';
+SELECT '[1,2,3]'::intvec <= '[1,2,3]';
+SELECT '[1,2,3]'::intvec <= '[1,2]';
+SELECT '[1,2,3]'::intvec = '[1,2,3]';
+SELECT '[1,2,3]'::intvec = '[1,2]';
+SELECT '[1,2,3]'::intvec != '[1,2,3]';
+SELECT '[1,2,3]'::intvec != '[1,2]';
+SELECT '[1,2,3]'::intvec >= '[1,2,3]';
+SELECT '[1,2,3]'::intvec >= '[1,2]';
+SELECT '[1,2,3]'::intvec > '[1,2,3]';
+SELECT '[1,2,3]'::intvec > '[1,2]';
+
+SELECT intvec_cmp('[1,2,3]', '[1,2,3]');
+SELECT intvec_cmp('[1,2,3]', '[0,0,0]');
+SELECT intvec_cmp('[0,0,0]', '[1,2,3]');
+SELECT intvec_cmp('[1,2]', '[1,2,3]');
+SELECT intvec_cmp('[1,2,3]', '[1,2]');
+SELECT intvec_cmp('[1,2]', '[2,3,4]');
+SELECT intvec_cmp('[2,3]', '[1,2,3]');
+
+SELECT vector_dims('[1,2,3]'::intvec);
+
+SELECT l2_distance('[0,0]'::intvec, '[3,4]');
+SELECT l2_distance('[0,0]'::intvec, '[0,1]');
+SELECT l2_distance('[1,2]'::intvec, '[3]');
+SELECT '[0,0]'::intvec <-> '[3,4]';
+
+SELECT inner_product('[1,2]'::intvec, '[3,4]');
+SELECT inner_product('[1,2]'::intvec, '[3]');
+SELECT inner_product('[127]'::intvec, '[127]');
+SELECT '[1,2]'::intvec <#> '[3,4]';
+
+SELECT cosine_distance('[1,2]'::intvec, '[2,4]');
+SELECT cosine_distance('[1,2]'::intvec, '[0,0]');
+SELECT cosine_distance('[1,1]'::intvec, '[1,1]');
+SELECT cosine_distance('[1,0]'::intvec, '[0,2]');
+SELECT cosine_distance('[1,1]'::intvec, '[-1,-1]');
+SELECT cosine_distance('[1,2]'::intvec, '[3]');
+SELECT '[1,2]'::intvec <=> '[2,4]';
+
+SELECT l1_distance('[0,0]'::intvec, '[3,4]');
+SELECT l1_distance('[0,0]'::intvec, '[0,1]');
+SELECT l1_distance('[1,2]'::intvec, '[3]');

test/t/033_comparison.pl

@@ -40,6 +40,10 @@ for (1 .. 50)
 	$actual = $node->safe_psql("postgres", "SELECT halfvec_cmp(v::halfvec, '$query'::real[]::halfvec) FROM tst");
 	is($expected, $actual);
 
+	# Test intvec
+	$actual = $node->safe_psql("postgres", "SELECT intvec_cmp(v::integer[]::intvec, '$query'::integer[]::intvec) FROM tst");
+	is($expected, $actual);
+
 	# Test sparsevec
 	$actual = $node->safe_psql("postgres", "SELECT sparsevec_cmp(v::vector::sparsevec, '$query'::real[]::vector::sparsevec) FROM tst");
 	is($expected, $actual);

test/t/034_distance_functions.pl

@@ -45,6 +45,10 @@ for my $function (@functions)
 		my $actual = $node->safe_psql("postgres", "SELECT $function(v::halfvec, '$query'::vector::halfvec) FROM tst");
 		is($expected, $actual, "halfvec $function");
 
+		# Test intvec
+		$actual = $node->safe_psql("postgres", "SELECT $function(v::real[]::integer[]::intvec, '$query'::vector::real[]::integer[]::intvec) FROM tst");
+		is($expected, $actual, "intvec $function");
+
 		# Test sparsevec
 		$actual = $node->safe_psql("postgres", "SELECT $function(v::sparsevec, '$query'::vector::sparsevec) FROM tst");
 		is($expected, $actual, "sparsevec $function");

test/t/037_inputs.pl

@@ -12,8 +12,8 @@ $node->start;
 # Create extension
 $node->safe_psql("postgres", "CREATE EXTENSION vector;");
 
-my @types = ("vector", "halfvec", "sparsevec");
+my @types = ("vector", "halfvec", "intvec", "sparsevec");
-my @inputs = ("[1.23,4.56,7.89]", "[1.23,4.56,7.89]", "{1:1.23,2:4.56,3:7.89}/3");
+my @inputs = ("[1.23,4.56,7.89]", "[1.23,4.56,7.89]", "[1,2,3]", "{1:1.23,2:4.56,3:7.89}/3");
 my @subs = (" ", " ", ",", ":", "-", "1", "9", "\0", "2147483648", "-2147483649");
 
 for my $i (0 .. $#types)

test/t/045_hnsw_intvec_build_recall.pl

@@ -0,0 +1,132 @@
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+my $node;
+my @queries = ();
+my @expected;
+my $limit = 20;
+my $dim = 10;
+my $array_sql = join(",", ('(random() * 255)::int - 128') x $dim);
+
+sub test_recall
+{
+	my ($min, $operator) = @_;
+	my $correct = 0;
+	my $total = 0;
+
+	my $explain = $node->safe_psql("postgres", qq(
+		SET enable_seqscan = off;
+		EXPLAIN ANALYZE SELECT i FROM tst ORDER BY v $operator '$queries[0]' LIMIT $limit;
+	));
+	like($explain, qr/Index Scan/);
+
+	for my $i (0 .. $#queries)
+	{
+		my $actual = $node->safe_psql("postgres", qq(
+			SET enable_seqscan = off;
+			SELECT i FROM tst ORDER BY v $operator '$queries[$i]' LIMIT $limit;
+		));
+		my @actual_ids = split("\n", $actual);
+		my %actual_set = map { $_ => 1 } @actual_ids;
+
+		my @expected_ids = split("\n", $expected[$i]);
+
+		foreach (@expected_ids)
+		{
+			if (exists($actual_set{$_}))
+			{
+				$correct++;
+			}
+			$total++;
+		}
+	}
+
+	cmp_ok($correct / $total, ">=", $min, $operator);
+}
+
+# Initialize node
+$node = PostgreSQL::Test::Cluster->new('node');
+$node->init;
+$node->start;
+
+# Create table
+$node->safe_psql("postgres", "CREATE EXTENSION vector;");
+$node->safe_psql("postgres", "CREATE TABLE tst (i int4, v intvec($dim));");
+$node->safe_psql("postgres",
+	"INSERT INTO tst SELECT i, ARRAY[$array_sql] FROM generate_series(1, 10000) i;"
+);
+
+# Generate queries
+for (1 .. 20)
+{
+	my @r = ();
+	for (1 .. $dim)
+	{
+		push(@r, int(rand(256)) - 128);
+	}
+	push(@queries, "[" . join(",", @r) . "]");
+}
+
+# Check each index type
+my @operators = ("<->", "<#>", "<=>", "<+>");
+my @opclasses = ("intvec_l2_ops", "intvec_ip_ops", "intvec_cosine_ops", "intvec_l1_ops");
+
+for my $i (0 .. $#operators)
+{
+	my $operator = $operators[$i];
+	my $opclass = $opclasses[$i];
+
+	# Get exact results
+	@expected = ();
+	foreach (@queries)
+	{
+		my $res = $node->safe_psql("postgres", "SELECT i FROM tst ORDER BY v $operator '$_' LIMIT $limit;");
+		push(@expected, $res);
+	}
+
+	# Build index serially
+	$node->safe_psql("postgres", qq(
+		SET max_parallel_maintenance_workers = 0;
+		CREATE INDEX idx ON tst USING hnsw (v $opclass);
+	));
+
+	# Test approximate results
+	my $min = 0.98;
+	test_recall($min, $operator);
+
+	$node->safe_psql("postgres", "DROP INDEX idx;");
+
+	# Build index in parallel in memory
+	my ($ret, $stdout, $stderr) = $node->psql("postgres", qq(
+		SET client_min_messages = DEBUG;
+		SET min_parallel_table_scan_size = 1;
+		CREATE INDEX idx ON tst USING hnsw (v $opclass);
+	));
+	is($ret, 0, $stderr);
+	like($stderr, qr/using \d+ parallel workers/);
+
+	# Test approximate results
+	test_recall($min, $operator);
+
+	$node->safe_psql("postgres", "DROP INDEX idx;");
+
+	# Build index in parallel on disk
+	# Set parallel_workers on table to use workers with low maintenance_work_mem
+	($ret, $stdout, $stderr) = $node->psql("postgres", qq(
+		ALTER TABLE tst SET (parallel_workers = 2);
+		SET client_min_messages = DEBUG;
+		SET maintenance_work_mem = '4MB';
+		CREATE INDEX idx ON tst USING hnsw (v $opclass);
+		ALTER TABLE tst RESET (parallel_workers);
+	));
+	is($ret, 0, $stderr);
+	like($stderr, qr/using \d+ parallel workers/);
+	like($stderr, qr/hnsw graph no longer fits into maintenance_work_mem/);
+
+	$node->safe_psql("postgres", "DROP INDEX idx;");
+}
+
+done_testing();

test/t/046_hnsw_intvec_insert_recall.pl

@@ -0,0 +1,113 @@
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+my $node;
+my @queries = ();
+my @expected;
+my $limit = 20;
+my $dim = 10;
+my $array_sql = join(",", ('(random() * 255)::int - 128') x $dim);
+
+sub test_recall
+{
+	my ($min, $operator) = @_;
+	my $correct = 0;
+	my $total = 0;
+
+	my $explain = $node->safe_psql("postgres", qq(
+		SET enable_seqscan = off;
+		EXPLAIN ANALYZE SELECT i FROM tst ORDER BY v $operator '$queries[0]' LIMIT $limit;
+	));
+	like($explain, qr/Index Scan/);
+
+	for my $i (0 .. $#queries)
+	{
+		my $actual = $node->safe_psql("postgres", qq(
+			SET enable_seqscan = off;
+			SELECT i FROM tst ORDER BY v $operator '$queries[$i]' LIMIT $limit;
+		));
+		my @actual_ids = split("\n", $actual);
+		my %actual_set = map { $_ => 1 } @actual_ids;
+
+		my @expected_ids = split("\n", $expected[$i]);
+
+		foreach (@expected_ids)
+		{
+			if (exists($actual_set{$_}))
+			{
+				$correct++;
+			}
+			$total++;
+		}
+	}
+
+	cmp_ok($correct / $total, ">=", $min, $operator);
+}
+
+# Initialize node
+$node = PostgreSQL::Test::Cluster->new('node');
+$node->init;
+$node->start;
+
+# Create table
+$node->safe_psql("postgres", "CREATE EXTENSION vector;");
+$node->safe_psql("postgres", "CREATE TABLE tst (i serial, v intvec($dim));");
+
+# Generate queries
+for (1 .. 20)
+{
+	my @r = ();
+	for (1 .. $dim)
+	{
+		push(@r, int(rand(256)) - 128);
+	}
+	push(@queries, "[" . join(",", @r) . "]");
+}
+
+# Check each index type
+my @operators = ("<->", "<#>", "<=>", "<+>");
+my @opclasses = ("intvec_l2_ops", "intvec_ip_ops", "intvec_cosine_ops", "intvec_l1_ops");
+
+for my $i (0 .. $#operators)
+{
+	my $operator = $operators[$i];
+	my $opclass = $opclasses[$i];
+
+	# Add index
+	$node->safe_psql("postgres", "CREATE INDEX idx ON tst USING hnsw (v $opclass);");
+
+	# Use concurrent inserts
+	$node->pgbench(
+		"--no-vacuum --client=10 --transactions=1000",
+		0,
+		[qr{actually processed}],
+		[qr{^$}],
+		"concurrent INSERTs",
+		{
+			"040_hnsw_intvec_insert_recall_$opclass" => "INSERT INTO tst (v) VALUES (ARRAY[$array_sql]);"
+		}
+	);
+
+	# Get exact results
+	@expected = ();
+	foreach (@queries)
+	{
+		my $res = $node->safe_psql("postgres", qq(
+			SET enable_indexscan = off;
+			SELECT i FROM tst ORDER BY v $operator '$_' LIMIT $limit;
+		));
+		push(@expected, $res);
+	}
+
+	# Test approximate results
+	my $min = 0.98;
+	test_recall($min, $operator);
+
+	$node->safe_psql("postgres", "DROP INDEX idx;");
+	$node->safe_psql("postgres", "TRUNCATE tst;");
+}
+
+done_testing();

test/t/047_hnsw_intvec_vacuum_recall.pl

@@ -0,0 +1,101 @@
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+my $node;
+my @queries = ();
+my @expected;
+my $limit = 20;
+my $dim = 10;
+my $array_sql = join(",", ('(random() * 255)::int - 128') x $dim);
+
+sub test_recall
+{
+	my ($min, $ef_search, $test_name) = @_;
+	my $correct = 0;
+	my $total = 0;
+
+	my $explain = $node->safe_psql("postgres", qq(
+		SET enable_seqscan = off;
+		SET hnsw.ef_search = $ef_search;
+		EXPLAIN ANALYZE SELECT i FROM tst ORDER BY v <-> '$queries[0]' LIMIT $limit;
+	));
+	like($explain, qr/Index Scan/);
+
+	for my $i (0 .. $#queries)
+	{
+		my $actual = $node->safe_psql("postgres", qq(
+			SET enable_seqscan = off;
+			SET hnsw.ef_search = $ef_search;
+			SELECT i FROM tst ORDER BY v <-> '$queries[$i]' LIMIT $limit;
+		));
+		my @actual_ids = split("\n", $actual);
+		my %actual_set = map { $_ => 1 } @actual_ids;
+
+		my @expected_ids = split("\n", $expected[$i]);
+
+		foreach (@expected_ids)
+		{
+			if (exists($actual_set{$_}))
+			{
+				$correct++;
+			}
+			$total++;
+		}
+	}
+
+	cmp_ok($correct / $total, ">=", $min, $test_name);
+}
+
+# Initialize node
+$node = PostgreSQL::Test::Cluster->new('node');
+$node->init;
+$node->start;
+
+# Create table
+$node->safe_psql("postgres", "CREATE EXTENSION vector;");
+$node->safe_psql("postgres", "CREATE TABLE tst (i int4, v intvec($dim));");
+$node->safe_psql("postgres", "ALTER TABLE tst SET (autovacuum_enabled = false);");
+$node->safe_psql("postgres",
+	"INSERT INTO tst SELECT i, ARRAY[$array_sql] FROM generate_series(1, 10000) i;"
+);
+
+# Add index
+$node->safe_psql("postgres", "CREATE INDEX ON tst USING hnsw (v intvec_l2_ops) WITH (m = 4, ef_construction = 8);");
+
+# Delete data
+$node->safe_psql("postgres", "DELETE FROM tst WHERE i > 2500;");
+
+# Generate queries
+for (1 .. 20)
+{
+	my @r = ();
+	for (1 .. $dim)
+	{
+		push(@r, int(rand(256)) - 128);
+	}
+	push(@queries, "[" . join(",", @r) . "]");
+}
+
+# Get exact results
+@expected = ();
+foreach (@queries)
+{
+	my $res = $node->safe_psql("postgres", qq(
+		SET enable_indexscan = off;
+		SELECT i FROM tst ORDER BY v <-> '$_' LIMIT $limit;
+	));
+	push(@expected, $res);
+}
+
+test_recall(0.18, $limit, "before vacuum");
+test_recall(0.84, 100, "before vacuum");
+
+# TODO Test concurrent inserts with vacuum
+$node->safe_psql("postgres", "VACUUM tst;");
+
+test_recall(0.84, $limit, "after vacuum");
+
+done_testing();

test/t/048_hnsw_intvec_duplicates.pl

@@ -0,0 +1,58 @@
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+# Initialize node
+my $node = PostgreSQL::Test::Cluster->new('node');
+$node->init;
+$node->start;
+
+# Create table
+$node->safe_psql("postgres", "CREATE EXTENSION vector;");
+$node->safe_psql("postgres", "CREATE TABLE tst (v intvec(3));");
+
+sub insert_vectors
+{
+	for my $i (1 .. 20)
+	{
+		$node->safe_psql("postgres", "INSERT INTO tst VALUES ('[1,1,1]');");
+	}
+}
+
+sub test_duplicates
+{
+	my $res = $node->safe_psql("postgres", qq(
+		SET enable_seqscan = off;
+		SET hnsw.ef_search = 1;
+		SELECT COUNT(*) FROM (SELECT * FROM tst ORDER BY v <-> '[1,1,1]') t;
+	));
+	is($res, 10);
+}
+
+# Test duplicates with build
+insert_vectors();
+$node->safe_psql("postgres", "CREATE INDEX idx ON tst USING hnsw (v intvec_l2_ops);");
+test_duplicates();
+
+# Reset
+$node->safe_psql("postgres", "TRUNCATE tst;");
+
+# Test duplicates with inserts
+insert_vectors();
+test_duplicates();
+
+# Test fallback path for inserts
+$node->pgbench(
+	"--no-vacuum --client=5 --transactions=100",
+	0,
+	[qr{actually processed}],
+	[qr{^$}],
+	"concurrent INSERTs",
+	{
+		"042_hnsw_intvec_duplicates" => "INSERT INTO tst VALUES ('[1,1,1]');"
+	}
+);
+
+done_testing();