Re: [HACKERS] [PATCH] Lockable views

On Mon, Feb 5, 2018 at 8:18 PM, Tatsuo Ishii <ishii@sraoss.co.jp> wrote:
> We have: CREATE VIEW v1 AS SELECT * FROM t1 WHERE i = (SELECT i FROM t2);
>
> 1. Session A tries to lock v1 (I suppose it tries to acquire lock in
> the order of t1, then t2). A acquires lock on t1 but yet on t2.
>
> 2. Another session B acquires lock on t2.
>
> 3. A continues to try to acquire lock on t2 (blocked).
>
> 4. B tries to acquire lock on t1. Deadlock occurs.

True.  But the same exact analysis also applies to this definition,
which contains no subquery:

CREATE VIEW v1 AS SELECT t1.* FROM t1, t2 WHERE t1.i = t2.i;

-- 
Robert Haas
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