PostgreSQL“delerable Delete”仍然在删除时命中约束

我想从两个表中删除行,这两个表通过一组可延迟约束相互依赖。为了简化本文,我模拟了一个简单的DB模式。

以下是两个表的说明:

tab-quarantine=> \d delete_from_me
       Table "public.delete_from_me"
  Column   |       Type        | Modifiers 
-----------+-------------------+-----------
 id        | character varying | not null
 extension | character varying | not null
Indexes:
    "delete_from_me_pkey" PRIMARY KEY, btree (id)

tab-quarantine=> \d constraining_table 
   Table "public.constraining_table"
 Column |       Type        | Modifiers 
--------+-------------------+-----------
 image  | character varying | not null
 type   | character varying | not null
Foreign-key constraints:
    "constraining_table_image_fkey" FOREIGN KEY (image) REFERENCES delete_from_me(id)
         ON UPDATE CASCADE
         ON DELETE RESTRICT DEFERRABLE

下面是一些我刚刚在里面罗列的样本数据:

tab-quarantine=> SELECT * FROM delete_from_me;
     id     | extension 
------------+-----------
 12345abcde | png
(1 row)

tab-quarantine=> SELECT * FROM constraining_table;
   image    |   type   
------------+----------
 12345abcde | select_me
(1 row)

BEGIN;
\set ON_ERROR_STOP 1
SET CONSTRAINTS ALL DEFERRED;
DELETE FROM delete_from_me WHERE id IN (
    SELECT image FROM constraining_table WHERE type = 'select_me'
);
DELETE FROM constraining_table WHERE type = 'select_me';
COMMIT;

此事务失败。当我单步执行并手动执行此操作时,将显示以下错误消息:

ERROR:  update or delete on table "delete_from_me" violates foreign key constraint "constraining_table_image_fkey" on table "constraining_table"
DETAIL:  Key (id)=(12345abcde) is still referenced from table "constraining_table".

为什么? 我不能按此顺序删除,因为约束在事务结束前不应生效?