Horton

Re: UPDATE of partition key

Amit Khandekar <amitdkhan.pg@gmail.com>

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From: Amit Khandekar <amitdkhan.pg@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-06-09T14:18:03Z
Lists: pgsql-hackers 
On 9 June 2017 at 19:10, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Thu, Jun 8, 2017 at 10:40 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Thu, Jun 8, 2017 at 7:01 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>> On Thu, Jun 8, 2017 at 1:33 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>>>> On Wed, Jun 7, 2017 at 5:46 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>>>> As far as I understand, it is to ensure that for deleted rows, nothing
>>>>> more needs to be done.  For example, see the below check in
>>>>> ExecUpdate/ExecDelete.
>>>>> if (!ItemPointerEquals(tupleid, &hufd.ctid))
>>>>> {
>>>>> ..
>>>>> }
>>>>> ..
>>>>>
>>>>> Also a similar check in ExecLockRows.  Now for deleted rows, if the
>>>>> t_ctid wouldn't point to itself, then in the mentioned functions, we
>>>>> were not in a position to conclude that the row is deleted.
>>>>
>>>> Right, so we would have to find all such checks and change them to use
>>>> some other method to conclude that the row is deleted.  What method
>>>> would we use?
>>>
>>> I think before doing above check we can simply check if ctid.ip_blkid
>>> contains InvalidBlockNumber, then return an error.
>>
>> Hmm, OK.  That case never happens today?
>>
>
> As per my understanding that case doesn't exist.  I will verify again
> once the patch is available.  I can take a crack at it if Amit
> Khandekar is busy with something else or is not comfortable in this
> area.

Amit, I was going to have a look at this, once I finish with the other
part. I was busy on getting that done first. But your comments/help
are always welcome.

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



-- 
Thanks,
-Amit Khandekar
EnterpriseDB Corporation
The Postgres Database Company

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.