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

On 2018-08-13 16:14:03 +0000, PG Bug reporting form wrote:
> Execute this query (multiple times!)
>
> select * from events where account in (select account from events where
> data->>'page' = 'success.html' limit 3);

Well, the subselect with thelimit going to return different results from
run to run. Unless you add an ORDER BY there's no guaranteed order in
which tuples are returned.  So I don't think it's surprising that you're
getting results that differ between runs.