Horton

Re: UPDATE of partition key

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-09-18T05:59:00Z
Lists: pgsql-hackers 
On Fri, Sep 15, 2017 at 4:55 PM, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> On 12 September 2017 at 12:39, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
>> On 12 September 2017 at 11:57, Dilip Kumar <dilipbalaut@gmail.com> wrote:
>>> On Tue, Sep 12, 2017 at 11:15 AM, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
>>>
> I found out that, in case when there is a DELETE statement trigger
> using transition tables, it's not only an issue of redundancy; it's a
> correctness issue. Since for transition tables both DELETE and UPDATE
> use the same old row tuplestore for capturing OLD table, that table
> gets duplicate rows: one from ExecARDeleteTriggers() and another from
> ExecARUpdateTriggers(). In presence of INSERT statement trigger using
> transition tables, both INSERT and UPDATE events have separate
> tuplestore, so duplicate rows don't show up in the UPDATE NEW table.
> But, nevertheless, we need to prevent NEW rows to be collected in the
> INSERT event tuplestore, and capture the NEW rows only in the UPDATE
> event tuplestore.
>
> In the attached patch, we first call ExecARUpdateTriggers(), and while
> doing that, we first save the info that a NEW row is already captured
> (mtstate->mt_transition_capture->tcs_update_old_table == true). If it
> captured, we pass NULL transition_capture pointer to
> ExecARDeleteTriggers() (and ExecARInsertTriggers) so that it does not
> again capture an extra row.
>
> Modified a testcase in update.sql by including DELETE statement
> trigger that uses transition tables.

Ok, this fix looks correct to me, I will review the latest patch.

-- 
Regards,
Dilip Kumar
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.