Re: BUG #15324: Non-deterministic behaviour from parallelised sub-query

Pavel Stehule <pavel.stehule@gmail.com> writes:
> 2018-08-13 19:26 GMT+02:00 Tom Lane <tgl@sss.pgh.pa.us>:
>> Likely, we need to treat the presence of a LIMIT/OFFSET in a sub-select
>> as making it parallel-unsafe, for exactly the reason that that makes
>> its results non-deterministic.

> Isn't it default behave of LIMIT/OFFSET without ORDER BY clause?

In principle, the planner could prove in some cases that the results
were deterministic even with LIMIT/OFFSET.  BuT I doubt it's worth
the trouble.  I certainly wouldn't advocate for such logic to be
part of a back-patched bug fix.

            regards, tom lane