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: 2017-09-06T16:17:51Z
Lists: pgsql-hackers 
On Mon, Sep 4, 2017 at 10:52 AM, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> On 4 September 2017 at 07:43, Amit Kapila <amit.kapila16@gmail.com> wrote:
> Oops sorry. Now attached.

I have done some basic testing and initial review of the patch.  I
have some comments/doubts.  I will continue the review.

+ if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_capture)
+ ExecARUpdateTriggers(estate, resultRelInfo, InvalidOid,

For passing invalid ItemPointer we are using InvalidOid, this seems
bit odd to me
are we using simmilar convention some other place? I think it would be better to
just pass 0?

------

- if ((event == TRIGGER_EVENT_DELETE && delete_old_table) ||
- (event == TRIGGER_EVENT_UPDATE && update_old_table))
+ if (oldtup != NULL &&
+ ((event == TRIGGER_EVENT_DELETE && delete_old_table) ||
+ (event == TRIGGER_EVENT_UPDATE && update_old_table)))
  {
  Tuplestorestate *old_tuplestore;

- Assert(oldtup != NULL);

Only if TRIGGER_EVENT_UPDATE it is possible that oldtup can be NULL,
so we have added an extra
check for oldtup and removed the Assert, but if  TRIGGER_EVENT_DELETE
we never expect it to be NULL.

Is it better to put Assert outside the condition check (Assert(oldtup
!= NULL || event == TRIGGER_EVENT_UPDATE)) ?
same for the newtup.

I think we should also explain in comments about why oldtup or newtup
can be NULL in case of if
TRIGGER_EVENT_UPDATE

-------

+    triggers affect the row being moved. As far as <literal>AFTER ROW</>
+    triggers are concerned, <literal>AFTER</> <command>DELETE</command> and
+    <literal>AFTER</> <command>INSERT</command> triggers are applied; but
+    <literal>AFTER</> <command>UPDATE</command> triggers are not applied
+    because the <command>UPDATE</command> has been converted to a
+    <command>DELETE</command> and <command>INSERT</command>.

Above comments says that ARUpdate trigger is not fired but below code call
ARUpdateTrigger

+ if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_capture)
+ ExecARUpdateTriggers(estate, resultRelInfo, InvalidOid,
+ NULL,
+ tuple,
+ NULL,
+ mtstate->mt_transition_capture);


-- 
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.