From 02c4f4884cca01c90e20286254905d27e042e9a7 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Mon, 25 Mar 2024 22:44:51 -0700
Subject: [PATCH] Added support for indexing Jaccard distance

---
 README.md                      |  1 +
 sql/vector--0.6.2--0.7.0.sql   | 10 ++++++++++
 sql/vector.sql                 | 10 ++++++++++
 test/expected/hnsw_jaccard.out | 21 +++++++++++++++++++++
 test/sql/hnsw_jaccard.sql      | 12 ++++++++++++
 5 files changed, 54 insertions(+)
 create mode 100644 test/expected/hnsw_jaccard.out
 create mode 100644 test/sql/hnsw_jaccard.sql

diff --git a/README.md b/README.md
index 1364297..84dc7be 100644
--- a/README.md
+++ b/README.md
@@ -722,6 +722,7 @@ sum(vector) → vector | sum | 0.5.0
 Operator | Description | Added
 --- | --- | ---
 <~> | Hamming distance | 0.7.0
+<%> | Jaccard distance | 0.7.0
 
 ### Bit Functions
 
diff --git a/sql/vector--0.6.2--0.7.0.sql b/sql/vector--0.6.2--0.7.0.sql
index ba4504d..68409d3 100644
--- a/sql/vector--0.6.2--0.7.0.sql
+++ b/sql/vector--0.6.2--0.7.0.sql
@@ -15,7 +15,17 @@ CREATE OPERATOR <~> (
 	COMMUTATOR = '<~>'
 );
 
+CREATE OPERATOR <%> (
+	LEFTARG = bit, RIGHTARG = bit, PROCEDURE = jaccard_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);
+
+CREATE OPERATOR CLASS bit_jaccard_ops
+	FOR TYPE bit USING hnsw AS
+	OPERATOR 1 <%> (bit, bit) FOR ORDER BY float_ops,
+	FUNCTION 1 jaccard_distance(bit, bit);
diff --git a/sql/vector.sql b/sql/vector.sql
index 6edea66..fc253c6 100644
--- a/sql/vector.sql
+++ b/sql/vector.sql
@@ -304,7 +304,17 @@ CREATE OPERATOR <~> (
 	COMMUTATOR = '<~>'
 );
 
+CREATE OPERATOR <%> (
+	LEFTARG = bit, RIGHTARG = bit, PROCEDURE = jaccard_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);
+
+CREATE OPERATOR CLASS bit_jaccard_ops
+	FOR TYPE bit USING hnsw AS
+	OPERATOR 1 <%> (bit, bit) FOR ORDER BY float_ops,
+	FUNCTION 1 jaccard_distance(bit, bit);
diff --git a/test/expected/hnsw_jaccard.out b/test/expected/hnsw_jaccard.out
new file mode 100644
index 0000000..6524f00
--- /dev/null
+++ b/test/expected/hnsw_jaccard.out
@@ -0,0 +1,21 @@
+SET enable_seqscan = off;
+CREATE TABLE t (val bit(4));
+INSERT INTO t (val) VALUES (B'0000'), (B'1100'), (B'1111'), (NULL);
+CREATE INDEX ON t USING hnsw (val bit_jaccard_ops);
+INSERT INTO t (val) VALUES (B'1110');
+SELECT * FROM t ORDER BY val <%> B'1111';
+ val  
+------
+ 1111
+ 1110
+ 1100
+ 0000
+(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_jaccard.sql b/test/sql/hnsw_jaccard.sql
new file mode 100644
index 0000000..ca61c53
--- /dev/null
+++ b/test/sql/hnsw_jaccard.sql
@@ -0,0 +1,12 @@
+SET enable_seqscan = off;
+
+CREATE TABLE t (val bit(4));
+INSERT INTO t (val) VALUES (B'0000'), (B'1100'), (B'1111'), (NULL);
+CREATE INDEX ON t USING hnsw (val bit_jaccard_ops);
+
+INSERT INTO t (val) VALUES (B'1110');
+
+SELECT * FROM t ORDER BY val <%> B'1111';
+SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <%> (SELECT NULL::bit)) t2;
+
+DROP TABLE t;