diff --git a/sql/swh-func.sql b/sql/swh-func.sql
--- a/sql/swh-func.sql
+++ b/sql/swh-func.sql
@@ -931,24 +931,6 @@
     select dir_id, name from path order by depth desc limit 1;
 $$;
 
-
--- Walk the revision history starting from a given revision, until a matching
--- occurrence is found. Return all occurrence information if one is found, NULL
--- otherwise.
-create or replace function swh_revision_find_occurrence(revision_id sha1_git)
-    returns occurrence
-    language sql
-    stable
-as $$
-	select origin, branch, target, target_type
-  from swh_revision_list_children(ARRAY[revision_id] :: bytea[]) as rev_list
-	left join occurrence_history occ_hist
-  on rev_list.id = occ_hist.target
-	where occ_hist.origin is not null and
-        occ_hist.target_type = 'revision'
-	limit 1;
-$$;
-
 -- Find the visit of origin id closest to date visit_date
 create or replace function swh_visit_find_by_date(origin bigint, visit_date timestamptz default NOW())
     returns origin_visit
@@ -1209,15 +1191,6 @@
 $$;
 
 
-create or replace function swh_occurrence_by_origin_visit(origin_id bigint, visit_id bigint)
-    returns setof occurrence
-    language sql
-    stable
-as $$
-  select origin, branch, target, target_type from occurrence_history
-  where origin = origin_id and visit_id = ANY(visits);
-$$;
-
 -- end revision_metadata functions
 -- origin_metadata functions
 create type origin_metadata_signature as (
diff --git a/sql/swh-schema.sql b/sql/swh-schema.sql
--- a/sql/swh-schema.sql
+++ b/sql/swh-schema.sql
@@ -12,7 +12,7 @@
 
 -- latest schema version
 insert into dbversion(version, release, description)
-      values(121, now(), 'Work In Progress');
+      values(122, now(), 'Work In Progress');
 
 -- a SHA1 checksum
 create domain sha1 as bytea check (length(value) = 20);
diff --git a/sql/upgrades/122.sql b/sql/upgrades/122.sql
new file mode 100644
--- /dev/null
+++ b/sql/upgrades/122.sql
@@ -0,0 +1,11 @@
+-- SWH DB schema upgrade
+-- from_version: 121
+-- to_version: 122
+-- description: Remove some unused functions
+
+insert into dbversion(version, release, description)
+      values(122, now(), 'Work In Progress');
+
+DROP FUNCTION swh_occurrence_by_origin_visit(origin_id bigint, visit_id bigint);
+
+DROP FUNCTION swh_revision_find_occurrence(revision_id public.sha1_git);
diff --git a/swh/storage/db.py b/swh/storage/db.py
--- a/swh/storage/db.py
+++ b/swh/storage/db.py
@@ -622,27 +622,6 @@
 
     occurrence_cols = ['origin', 'branch', 'target', 'target_type']
 
-    def occurrence_by_origin_visit(self, origin_id, visit_id, cur=None):
-        """Retrieve all occurrences for a particular origin_visit.
-
-        Args:
-            origin_id: the origin concerned
-            visit_id: The visit step for that origin
-
-        Yields:
-            The occurrence's history visits
-
-        """
-        cur = self._cursor(cur)
-
-        query = """\
-            SELECT %s
-            FROM swh_occurrence_by_origin_visit(%%s, %%s)
-            """ % (', '.join(self.occurrence_cols))
-
-        cur.execute(query, (origin_id, visit_id))
-        yield from cursor_to_bytes(cur)
-
     @staticmethod
     def mangle_query_key(key, main_table):
         if key == 'id':