Fix operator classes for lantern_hnsw access method

sql/lantern.sql

@@ -1,8 +1,74 @@
 -- Definitions concerning our hnsw-based index data strucuture
-
 CREATE FUNCTION hnsw_handler(internal) RETURNS index_am_handler
 	AS 'MODULE_PATHNAME' LANGUAGE C;
 
+-- functions
+CREATE FUNCTION ldb_generic_dist(real[], real[]) RETURNS real
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION ldb_generic_dist(integer[], integer[]) RETURNS real
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION l2sq_dist(real[], real[]) RETURNS real
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION cos_dist(real[], real[]) RETURNS real
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION hamming_dist(integer[], integer[]) RETURNS integer
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+-- operators
+CREATE OPERATOR <-> (
+	LEFTARG = real[], RIGHTARG = real[], PROCEDURE = ldb_generic_dist,
+	COMMUTATOR = '<->'
+);
+
+CREATE OPERATOR <-> (
+	LEFTARG = integer[], RIGHTARG = integer[], PROCEDURE = ldb_generic_dist,
+	COMMUTATOR = '<->'
+);
+
+-- operator classes
+CREATE OR REPLACE FUNCTION _create_ldb_operator_classes(access_method_name TEXT) RETURNS BOOLEAN AS $$
+DECLARE
+    dist_l2sq_ops TEXT;
+    dist_cos_ops TEXT;
+    dist_hamming_ops TEXT;
+BEGIN
+    -- Construct the SQL statement to create the operator classes dynamically.
+    dist_l2sq_ops := '
+        CREATE OPERATOR CLASS dist_l2sq_ops
+        DEFAULT FOR TYPE real[] USING ' || access_method_name || ' AS
+        OPERATOR 1 <-> (real[], real[]) FOR ORDER BY float_ops,
+        FUNCTION 1 l2sq_dist(real[], real[]);
+    ';
+
+    dist_cos_ops := '
+        CREATE OPERATOR CLASS dist_cos_ops
+        FOR TYPE real[] USING ' || access_method_name || ' AS
+        OPERATOR 1 <-> (real[], real[]) FOR ORDER BY float_ops,
+        FUNCTION 1 cos_dist(real[], real[]);
+    ';
+
+    dist_hamming_ops := '
+        CREATE OPERATOR CLASS dist_hamming_ops
+        FOR TYPE integer[] USING ' || access_method_name || ' AS
+        OPERATOR 1 <-> (integer[], integer[]) FOR ORDER BY float_ops,
+        FUNCTION 1 hamming_dist(integer[], integer[]);
+    ';
+
+    -- Execute the dynamic SQL statement.
+    EXECUTE dist_l2sq_ops;
+    EXECUTE dist_cos_ops;
+    EXECUTE dist_hamming_ops;
+
+    RETURN TRUE;
+END;
+$$ LANGUAGE plpgsql VOLATILE;
+
+
+-- Create access method
 DO $BODY$
 DECLARE
 	hnsw_am_exists boolean;
@@ -41,55 +107,14 @@ BEGIN
 
 
 	IF hnsw_am_exists THEN
+		PERFORM _create_ldb_operator_classes('lantern_hnsw');
 		RAISE WARNING 'Access method(index type) "hnsw" already exists. Creating lantern_hnsw access method';
 	ELSE
 		-- create access method
 		CREATE ACCESS METHOD hnsw TYPE INDEX HANDLER hnsw_handler;
 		COMMENT ON ACCESS METHOD hnsw IS 'LanternDB access method for vector embeddings, based on the hnsw algorithm';
+		PERFORM _create_ldb_operator_classes('hnsw');
 	END IF;
 END;
 $BODY$
 LANGUAGE plpgsql;
-
--- functions
-CREATE FUNCTION ldb_generic_dist(real[], real[]) RETURNS real
-	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
-
-CREATE FUNCTION ldb_generic_dist(integer[], integer[]) RETURNS real
-	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
-
-CREATE FUNCTION l2sq_dist(real[], real[]) RETURNS real
-	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
-
-CREATE FUNCTION cos_dist(real[], real[]) RETURNS real
-	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
-
-CREATE FUNCTION hamming_dist(integer[], integer[]) RETURNS integer
-	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
-
--- operators
-CREATE OPERATOR <-> (
-	LEFTARG = real[], RIGHTARG = real[], PROCEDURE = ldb_generic_dist,
-	COMMUTATOR = '<->'
-);
-
-CREATE OPERATOR <-> (
-	LEFTARG = integer[], RIGHTARG = integer[], PROCEDURE = ldb_generic_dist,
-	COMMUTATOR = '<->'
-);
-
--- operator classes
-CREATE OPERATOR CLASS dist_l2sq_ops
-  DEFAULT FOR TYPE real[] USING hnsw AS
-	OPERATOR 1 <-> (real[], real[]) FOR ORDER BY float_ops,
-	FUNCTION 1 l2sq_dist(real[], real[]);
-
-CREATE OPERATOR CLASS dist_cos_ops
-	FOR TYPE real[] USING hnsw AS
-	OPERATOR 1 <-> (real[], real[]) FOR ORDER BY float_ops,
-	FUNCTION 1 cos_dist(real[], real[]);
-
-CREATE OPERATOR CLASS dist_hamming_ops
-	FOR TYPE integer[] USING hnsw AS
-	OPERATOR 1 <-> (integer[], integer[]) FOR ORDER BY float_ops,
-	FUNCTION 1 hamming_dist(integer[], integer[]);

sql/updates/0.0.4-latest.sql

@@ -9,7 +9,45 @@ SELECT EXISTS (
 	WHERE typname = 'vector'
 ) INTO pgvector_exists;
 
+CREATE OR REPLACE FUNCTION _create_ldb_operator_classes(access_method_name TEXT) RETURNS BOOLEAN AS $$
+DECLARE
+    dist_l2sq_ops TEXT;
+    dist_cos_ops TEXT;
+    dist_hamming_ops TEXT;
+BEGIN
+    -- Construct the SQL statement to create the operator classes dynamically.
+    dist_l2sq_ops := '
+        CREATE OPERATOR CLASS dist_l2sq_ops
+        DEFAULT FOR TYPE real[] USING ' || access_method_name || ' AS
+        OPERATOR 1 <-> (real[], real[]) FOR ORDER BY float_ops,
+        FUNCTION 1 l2sq_dist(real[], real[]);
+    ';
+
+    dist_cos_ops := '
+        CREATE OPERATOR CLASS dist_cos_ops
+        FOR TYPE real[] USING ' || access_method_name || ' AS
+        OPERATOR 1 <-> (real[], real[]) FOR ORDER BY float_ops,
+        FUNCTION 1 cos_dist(real[], real[]);
+    ';
+
+    dist_hamming_ops := '
+        CREATE OPERATOR CLASS dist_hamming_ops
+        FOR TYPE integer[] USING ' || access_method_name || ' AS
+        OPERATOR 1 <-> (integer[], integer[]) FOR ORDER BY float_ops,
+        FUNCTION 1 hamming_dist(integer[], integer[]);
+    ';
+
+    -- Execute the dynamic SQL statement.
+    EXECUTE dist_l2sq_ops;
+    EXECUTE dist_cos_ops;
+    EXECUTE dist_hamming_ops;
+
+    RETURN TRUE;
+END;
+$$ LANGUAGE plpgsql VOLATILE;
+
 IF pgvector_exists THEN
 			CREATE FUNCTION l2sq_dist(vector, vector) RETURNS float8
 					AS 'MODULE_PATHNAME', 'vector_l2sq_dist' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+ 			PERFORM _create_ldb_operator_classes('lantern_hnsw');
 END IF

test/expected/hnsw_vector.out

@@ -194,3 +194,51 @@ CREATE INDEX ON test_table USING lantern_hnsw (int_to_fixed_binary_vector(id)) W
 INFO:  done init usearch index
 INFO:  inserted 3 elements
 INFO:  done saving 3 vectors
+-- Make sure that lantern_hnsw is working correctly alongside pgvector
+CREATE TABLE small_world_arr (id SERIAL PRIMARY KEY, v REAL[]);
+INSERT INTO small_world_arr (v) VALUES ('{0,0,0}'), ('{0,0,1}'), ('{0,0,2}');
+CREATE INDEX l2_idx ON small_world_arr USING lantern_hnsw(v) WITH (dim=3, m=2);
+INFO:  done init usearch index
+INFO:  inserted 3 elements
+INFO:  done saving 3 vectors
+EXPLAIN (COSTS FALSE) SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];
+                 QUERY PLAN                 
+--------------------------------------------
+ Index Scan using l2_idx on small_world_arr
+   Order By: (v <-> '{0,0,0}'::real[])
+(2 rows)
+
+SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];
+ id 
+----
+  1
+  2
+  3
+(3 rows)
+
+DROP INDEX l2_idx;
+CREATE INDEX cos_idx ON small_world_arr USING lantern_hnsw(v) WITH (m=2);
+INFO:  done init usearch index
+INFO:  inserted 3 elements
+INFO:  done saving 3 vectors
+SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];
+ id 
+----
+  1
+  2
+  3
+(3 rows)
+
+DROP INDEX cos_idx;
+CREATE INDEX ham_idx ON small_world_arr USING lantern_hnsw(v) WITH (m=3);
+INFO:  done init usearch index
+INFO:  inserted 3 elements
+INFO:  done saving 3 vectors
+SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];
+ id 
+----
+  1
+  2
+  3
+(3 rows)
+

test/sql/hnsw_vector.sql

@@ -99,3 +99,16 @@ END;
 $$ LANGUAGE plpgsql IMMUTABLE;
 
 CREATE INDEX ON test_table USING lantern_hnsw (int_to_fixed_binary_vector(id)) WITH (M=2);
+
+-- Make sure that lantern_hnsw is working correctly alongside pgvector
+CREATE TABLE small_world_arr (id SERIAL PRIMARY KEY, v REAL[]);
+INSERT INTO small_world_arr (v) VALUES ('{0,0,0}'), ('{0,0,1}'), ('{0,0,2}');
+CREATE INDEX l2_idx ON small_world_arr USING lantern_hnsw(v) WITH (dim=3, m=2);
+EXPLAIN (COSTS FALSE) SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];
+SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];
+DROP INDEX l2_idx;
+CREATE INDEX cos_idx ON small_world_arr USING lantern_hnsw(v) WITH (m=2);
+SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];
+DROP INDEX cos_idx;
+CREATE INDEX ham_idx ON small_world_arr USING lantern_hnsw(v) WITH (m=3);
+SELECT id FROM small_world_arr ORDER BY v <-> ARRAY[0,0,0];