Re: same query but different result on pg16devel and pg15.2

Attached file included table schema information, but no data.

tender wang <tndrwang(at)gmail(dot)com> 于2023年4月4日周二 10:53写道：

> Hi hackers,
> I encounter a problem, as shown below:
>
> query:
> select
> ref_0.ps_suppkey as c0,
> ref_1.c_acctbal as c1,
> ref_2.o_totalprice as c2,
> ref_2.o_orderpriority as c3,
> ref_2.o_clerk as c4
> from
> public.partsupp as ref_0
> left join public.nation as sample_0
> inner join public.customer as sample_1
> on (false)
> on (true)
> left join public.customer as ref_1
> right join public.orders as ref_2
> on (false)
> left join public.supplier as ref_3
> on (false)
> on (sample_0.n_comment = ref_1.c_name )
> where (8 <= NULLIF(CASE WHEN (o_orderkey IS NOT NULL) THEN 4 ELSE 4 END,
> CASE WHEN (o_orderdate >= o_orderdate) THEN 95 ELSE 95 END))
> order by c0, c1, c2, c3, c4 limit 1;
>
> on pg16devel:
> c0 | c1 | c2 | c3 | c4
> ----+----+----+----+----
> 1 | | | |
> (1 row)
> plan:
> QUERY PLAN
>
>
> ---------------------------------------------------------------------------------------
> Limit
> -> Sort
> Sort Key: ref_0.ps_suppkey, c_acctbal, o_totalprice,
> o_orderpriority, o_clerk
> -> Nested Loop Left Join
> -> Seq Scan on partsupp ref_0
> -> Result
> One-Time Filter: false
> (7 rows)
>
> on pg15.2:
> c0 | c1 | c2 | c3 | c4
> ----+----+----+----+----
> (0 rows)
> plan:
>
> QUERY PLAN
>
>
> -------------------------------------------------------------------------------------------------------------------------------------------------------
> Limit
> -> Sort
> Sort Key: ref_0.ps_suppkey, c_acctbal, o_totalprice,
> o_orderpriority, o_clerk
> -> Hash Left Join
> Hash Cond: ((n_comment)::text = (c_name)::text)
> Filter: (8 <= NULLIF(CASE WHEN (o_orderkey IS NOT NULL)
> THEN 4 ELSE 4 END, CASE WHEN (o_orderdate >= o_orderdate) THEN 95 ELSE 95
> END))
> -> Nested Loop Left Join
> -> Seq Scan on partsupp ref_0
> -> Result
> One-Time Filter: false
> -> Hash
> -> Result
> One-Time Filter: false
> (13 rows)
>
>
>
> regards, tender
> wang
>