From 263e684824b4e8b59196420748c56f9e3a323bc0 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Mon, 25 Mar 2024 15:25:04 -0700
Subject: [PATCH] Started indexing

---
 sql/vector--0.6.2--0.6.3.sql   | 10 ++++++++++
 sql/vector.sql                 | 10 ++++++++++
 test/expected/hnsw_hamming.out | 21 +++++++++++++++++++++
 test/sql/hnsw_hamming.sql      | 12 ++++++++++++
 4 files changed, 53 insertions(+)
 create mode 100644 test/expected/hnsw_hamming.out
 create mode 100644 test/sql/hnsw_hamming.sql

diff --git a/sql/vector--0.6.2--0.6.3.sql b/sql/vector--0.6.2--0.6.3.sql
index 5fcab73..5484808 100644
--- a/sql/vector--0.6.2--0.6.3.sql
+++ b/sql/vector--0.6.2--0.6.3.sql
@@ -3,3 +3,13 @@
 
 CREATE FUNCTION hamming_distance(bit, bit) RETURNS float8
 	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE OPERATOR <~> (
+	LEFTARG = bit, RIGHTARG = bit, PROCEDURE = hamming_distance,
+	COMMUTATOR = '<~>'
+);
+
+CREATE OPERATOR CLASS bit_hamming_ops
+	FOR TYPE bit USING hnsw AS
+	OPERATOR 1 <~> (bit, bit) FOR ORDER BY float_ops,
+	FUNCTION 1 hamming_distance(bit, bit);
diff --git a/sql/vector.sql b/sql/vector.sql
index eb32566..3cbaadb 100644
--- a/sql/vector.sql
+++ b/sql/vector.sql
@@ -292,3 +292,13 @@ CREATE OPERATOR CLASS vector_cosine_ops
 
 CREATE FUNCTION hamming_distance(bit, bit) RETURNS float8
 	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE OPERATOR <~> (
+	LEFTARG = bit, RIGHTARG = bit, PROCEDURE = hamming_distance,
+	COMMUTATOR = '<~>'
+);
+
+CREATE OPERATOR CLASS bit_hamming_ops
+	FOR TYPE bit USING hnsw AS
+	OPERATOR 1 <~> (bit, bit) FOR ORDER BY float_ops,
+	FUNCTION 1 hamming_distance(bit, bit);
diff --git a/test/expected/hnsw_hamming.out b/test/expected/hnsw_hamming.out
new file mode 100644
index 0000000..5c73dc0
--- /dev/null
+++ b/test/expected/hnsw_hamming.out
@@ -0,0 +1,21 @@
+SET enable_seqscan = off;
+CREATE TABLE t (val bit(3));
+INSERT INTO t (val) VALUES (B'000'), (B'100'), (B'111'), (NULL);
+CREATE INDEX ON t USING hnsw (val bit_hamming_ops);
+INSERT INTO t (val) VALUES ('110');
+SELECT * FROM t ORDER BY val <~> '111';
+ val 
+-----
+ 111
+ 110
+ 100
+ 000
+(4 rows)
+
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <~> (SELECT NULL::bit)) t2;
+ count 
+-------
+     4
+(1 row)
+
+DROP TABLE t;
diff --git a/test/sql/hnsw_hamming.sql b/test/sql/hnsw_hamming.sql
new file mode 100644
index 0000000..1e096e1
--- /dev/null
+++ b/test/sql/hnsw_hamming.sql
@@ -0,0 +1,12 @@
+SET enable_seqscan = off;
+
+CREATE TABLE t (val bit(3));
+INSERT INTO t (val) VALUES (B'000'), (B'100'), (B'111'), (NULL);
+CREATE INDEX ON t USING hnsw (val bit_hamming_ops);
+
+INSERT INTO t (val) VALUES ('110');
+
+SELECT * FROM t ORDER BY val <~> '111';
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <~> (SELECT NULL::bit)) t2;
+
+DROP TABLE t;