Re: UPDATE of partition key

On Thu, Feb 16, 2017 at 03:39:30PM +0530, Amit Khandekar wrote:
> >>>> and then run ExecFindPartition()
> >>>> again using the root. Will check. I am not sure right now how involved
> >>>> that would turn out to be, but I think that logic would not change the
> >>>> existing code, so in that sense it is not invasive.
> >>>
> >>> I couldn't understand why run ExecFindPartition() again on the root
> >>> partitioned table, can you clarify? ISTM, we just want to tell the user
> >>> in the HINT that trying the same update query with root partitioned table
> >>> might work. I'm not sure if it would work instead to find some
> >>> intermediate partitioned table (that is, between the root and the one that
> >>> update query was tried with) to include in the HINT.
> >>
> >> What I had in mind was : Give that hint only if there *was* a
> >> subpartition that could accommodate that row. And if found, we can
> >> only include the subpartition name.
> >
> > Asking to try the update query with the root table sounds like a good
> > enough hint. Trying to find the exact sub-partition (I assume you mean to
> > imply sub-tree here) seems like an overkill, IMHO.
> Yeah ... I was thinking , anyways it's an error condition, so why not
> let the server spend a bit more CPU and get the right sub-partition
> for the message. If we decide to write code to find the root
> partition, then it's just a matter of another function
> ExecFindPartition().
>
> Also, I was thinking : give the hint *only* if we know there is a
> right sub-partition. Otherwise, it might distract the user.

If this is relatively straight-forward, it'd be great. More
actionable knowledge is better.

Thanks for taking this on.

Best,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter
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