Horton

Re: UPDATE of partition key

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-05-29T09:26:22Z
Lists: pgsql-hackers 
On Mon, May 29, 2017 at 11:20 AM, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> On 24 May 2017 at 20:16, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> On Wed, May 24, 2017 at 8:14 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>> Apart from above, there is one open issue [1]
>>>
>>
>> Forget to mention the link, doing it now.
>>
>> [1] - https://www.postgresql.org/message-id/CAA4eK1KEZQ%2BCyXbBzfn1jFHoEfa_OemDLhLyy7xfD1QUZLo1DQ%40mail.gmail.com
>
> I am not sure right now whether making the t_ctid of such tuples to
> Invalid would be a right option, especially because I think there can
> be already some other meaning if t_ctid is not valid.
>

AFAIK, this is used to point to current tuple itself or newer version
of a tuple or is used in speculative inserts (refer comments above
HeapTupleHeaderData in htup_details.h).  Can you mention what other
meaning are you referring here for InvalidBlockId in t_ctid?

> But may be we
> can check this more.
>
> If we decide to error out using some way, I would be inclined towards
> considering re-using some combinations of infomask bits (like
> HEAP_MOVED_OFF as suggested upthread) rather than using invalid t_ctid
> value.
>
> But I think, we can also take step-by-step approach even for v11. If
> we agree that it is ok to silently do the updates as long as we
> document the behaviour, we can go ahead and do this, and then as a
> second step, implement error handling as a separate patch. If that
> patch does not materialize, we at least have the current behaviour
> documented.
>

I think that is sensible approach if we find the second step involves
big or complicated changes.


-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Avoid referencing off the end of subplan_partition_offsets.

  2. Allow UPDATE to move rows between partitions.

  3. Remove useless lookup of root partitioned rel in ExecInitModifyTable().

  4. Factor error generation out of ExecPartitionCheck.

  5. Minor preparatory refactoring for UPDATE row movement.

  6. Simplify and encapsulate tuple routing support code.

  7. Avoid coercing a whole-row variable that is already coerced.

  8. Use ResultRelInfo ** rather than ResultRelInfo * for tuple routing.

  9. Make RelationGetPartitionDispatchInfo expand depth-first.

  10. Expand partitioned tables in PartDesc order.

  11. Use a real RT index when setting up partition tuple routing.

  12. Fix transition tables for partition/inheritance.

  13. Fix confusion about number of subplans in partitioned INSERT setup.

  14. Prevent BEFORE triggers from violating partitioning constraints.

  15. Fire per-statement triggers on partitioned tables.

  16. Fix reporting of violations in ExecConstraints, again.

  17. Don't scan partitioned tables.

  18. Allow FDWs to push down quals without breaking EvalPlanQual rechecks.