Removed unused DatabaseOperations.last_insert_id() on PostgreSQL.
diff --git a/django/db/backends/postgresql/operations.py b/django/db/backends/postgresql/operations.py
index 2cc886a76d1eb..bff8e87d6870d 100644
--- a/django/db/backends/postgresql/operations.py
+++ b/django/db/backends/postgresql/operations.py
@@ -85,13 +85,6 @@ def lookup_cast(self, lookup_type, internal_type=None):
 
         return lookup
 
-    def last_insert_id(self, cursor, table_name, pk_name):
-        # Use pg_get_serial_sequence to get the underlying sequence name
-        # from the table name and column name (available since PostgreSQL 8)
-        cursor.execute("SELECT CURRVAL(pg_get_serial_sequence('%s','%s'))" % (
-            self.quote_name(table_name), pk_name))
-        return cursor.fetchone()[0]
-
     def no_limit_value(self):
         return None
 

Unused since 9eb2afddfa0165d69f3e506122c2aa2b68618591.