Flaws in RetractableTopNFunction.ComparatorWrapper#equals method prevent state access after restoration

[DONG, Weike]

Hi community,

Recently we found out an issue with the Top-N feature in blink planner, and
here is the JIRA ticket https://issues.apache.org/jira/browse/FLINK-18452.

After analysis, we believe that it is the flaw in the implementation of
equals method, as it does not take the random numbers within class names
and variables into account during comparison.

We would like to confirm whether this is actually an issue (mostly like
one, as it is 100% reproducible using standard SQL APIs).

Sincerely,
Weike

[Jark Wu-2]

Thanks for the feedback Weike,

I have responded under the JIRA issue. Let's keep the discussion in the
issue.

Best,
Jark

On Tue, 30 Jun 2020 at 11:52, DONG, Weike <[hidden email]> wrote:

> Hi community,
>
> Recently we found out an issue with the Top-N feature in blink planner, and
> here is the JIRA ticket https://issues.apache.org/jira/browse/FLINK-18452.
>
> After analysis, we believe that it is the flaw in the implementation of
> equals method, as it does not take the random numbers within class names
> and variables into account during comparison.
>
> We would like to confirm whether this is actually an issue (mostly like
> one, as it is 100% reproducible using standard SQL APIs).
>
> Sincerely,
> Weike
>