Yes, I'd say so.
2018-06-29 4:43 GMT+02:00 吴晓菊 :
> And it should be generic for HashJoin not only broadcast join, right?
>
>
> Chrysan Wu
> 吴晓菊
> Phone：+86 17717640807
>
>
> 2018-06-29 10:42 GMT+08:00 吴晓菊 :
>
>> Sorry for the mistake. You are right output ordering of broadcast join
>> can be the
And it should be generic for HashJoin not only broadcast join, right?
Chrysan Wu
吴晓菊
Phone：+86 17717640807
2018-06-29 10:42 GMT+08:00 吴晓菊 :
> Sorry for the mistake. You are right output ordering of broadcast join can
> be the order of big table in some types of join. I will prepare a PR and
>
Sorry for the mistake. You are right output ordering of broadcast join can
be the order of big table in some types of join. I will prepare a PR and
let you review later. Thanks a lot!
Chrysan Wu
吴晓菊
Phone：+86 17717640807
2018-06-29 0:00 GMT+08:00 Wenchen Fan :
> SortMergeJoin sorts its
SortMergeJoin sorts its children by join key, but broadcast join does not.
I think the output ordering of broadcast join has nothing to do with join
key.
On Thu, Jun 28, 2018 at 11:28 PM Marco Gaido wrote:
> I think the outputOrdering would be the one of the big table (if any) and
> it wouldn't
I think the outputOrdering would be the one of the big table (if any) and
it wouldn't matter if this involves the join keys or not. Am I wrong?
2018-06-28 17:01 GMT+02:00 吴晓菊 :
> Thanks for the reply.
> By looking into the SortMergeJoinExec, I think we can follow what
> SortMergeJoin do, for
Thanks for the reply.
By looking into the SortMergeJoinExec, I think we can follow what
SortMergeJoin do, for some types of join, if the children is ordered on
join keys, we can output the ordered join keys as output ordering.
Chrysan Wu
吴晓菊
Phone：+86 17717640807
2018-06-28 22:53 GMT+08:00
SortMergeJoin only reports ordering of the join keys, not the output
ordering of any child.
It seems reasonable to me that broadcast join should respect the output
ordering of the children. Feel free to submit a PR to fix it, thanks!
On Thu, Jun 28, 2018 at 10:07 PM 吴晓菊 wrote:
> Why we cannot
Why we cannot use the output order of big table?
Chrysan Wu
Phone：+86 17717640807
2018-06-28 21:48 GMT+08:00 Marco Gaido :
> The easy answer to this is that SortMergeJoin ensure an outputOrdering,
> while BroadcastHashJoin doesn't, ie. after running a BroadcastHashJoin you
> don't know which
The easy answer to this is that SortMergeJoin ensure an outputOrdering,
while BroadcastHashJoin doesn't, ie. after running a BroadcastHashJoin you
don't know which is going to be the order of the output since nothing
enforces it.
Hope this helps.
Thanks.
Marco
2018-06-28 15:46 GMT+02:00 吴晓菊 :
>
We see SortMergeJoinExec is implemented with
outputPartitioning while BroadcastHashJoinExec is only
implemented with outputPartitioning. Why is the design?
Chrysan Wu
Phone：+86 17717640807
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