The second SELECT with the ORDER BY clause returns 1, while the first SELECT returns NULL.

CREATE TABLE t0(c0);
CREATE VIEW v0(c0) AS SELECT t0.c0 FROM t0;
CREATE TABLE t1 (c0);
INSERT INTO t0 VALUES ('1');
SELECT SUM(count) FROM (SELECT 1 as count FROM t1 INNER JOIN v0 ON t1.c0 RIGHT OUTER JOIN t0 ON t1.c0 ORDER BY t1.c0);
-- Null
SELECT SUM(count) FROM (SELECT 1 as count FROM t1 INNER JOIN v0 ON t1.c0 RIGHT OUTER JOIN t0 ON t1.c0);
-- 1

Environment:

Version: 3.39.0

Commit ID: 318543a9

OS: Ubuntu 20.04

Configuration Options: ./configure --enable-all

Compiler: gcc-9

Client: CLI