> 2023年9月28日 12:26，David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com> 写道：
>
> On Wednesday, September 27, 2023, jacktby jacktby <jacktby(at)gmail(dot)com <mailto:jacktby(at)gmail(dot)com>> wrote:
>> postgres=# SET enable_seqscan = off;
>> SET
>> postgres=# explain select * from t;
>> QUERY PLAN
>> -------------------------------------------------------------------------
>> Seq Scan on t (cost=10000000000.00..10000000023.60 rows=1360 width=32)
>
> It wouldn’t cost 10billion to return the first tuple if that setting wasn’t working.
>
> That is the “discouragement” the documentation is referring to.
>
> I do agree the wording in the docs could be improved since it is a bit self-contradictory and unspecific, but it is explicitly clear a plan with sequential scan can still be chosen even with this set to off.
>
> David J.
>
Yes, I think that’s it.Thanks.