Horton

Re: UPDATE of partition key

Amul Sul <sulamul@gmail.com>

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From: amul sul <sulamul@gmail.com>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Amit Kapila <amit.kapila16@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: 2017-09-21T14:22:32Z
Lists: pgsql-hackers 
On Wed, Sep 20, 2017 at 9:27 PM, Amit Khandekar <amitdkhan.pg@gmail.com>
wrote:

> On 20 September 2017 at 00:06, Robert Haas <robertmhaas@gmail.com> wrote:
> > On Fri, Sep 15, 2017 at 7:25 AM, Amit Khandekar <amitdkhan.pg@gmail.com>
> wrote:
> >> [ new patch ]
>

  86 -           (event == TRIGGER_EVENT_UPDATE &&
!trigdesc->trig_update_after_row))
  87 +           (event == TRIGGER_EVENT_UPDATE &&
!trigdesc->trig_update_after_row) ||
  88 +           (event == TRIGGER_EVENT_UPDATE && (oldtup == NULL ||
newtup == NULL)))
  89             return;
  90     }


Either of oldtup or newtup will be valid at a time & vice versa.  Can we
improve
this check accordingly?

For e.g.:
(event == TRIGGER_EVENT_UPDATE && )(HeapTupleIsValid(oldtup) ^
ItemPointerIsValid(newtup)))))


 247
 248 +   /*
 249 +    * EDB: In case this is part of update tuple routing, put this row
into the
 250 +    * transition NEW TABLE if we are capturing transition tables. We
need to
 251 +    * do this separately for DELETE and INSERT because they happen on
 252 +    * different tables.
 253 +    */
 254 +   if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_
capture)
 255 +       ExecARUpdateTriggers(estate, resultRelInfo, NULL,
 256 +                    NULL,
 257 +                    tuple,
 258 +                    NULL,
 259 +                    mtstate->mt_transition_capture);
 260 +
 261     list_free(recheckIndexes);

 267
 268 +   /*
 269 +    * EDB: In case this is part of update tuple routing, put this row
into the
 270 +    * transition OLD TABLE if we are capturing transition tables. We
need to
 271 +    * do this separately for DELETE and INSERT because they happen on
 272 +    * different tables.
 273 +    */
 274 +   if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_
capture)
 275 +       ExecARUpdateTriggers(estate, resultRelInfo, tupleid,
 276 +                    oldtuple,
 277 +                    NULL,
 278 +                    NULL,
 279 +                    mtstate->mt_transition_capture);
 280 +

Initially, I wondered that why can't we have above code right after
​ExecInsert()​ & ​ExecIDelete()​ in ​ExecUpdate​ respectively?

We can do that for ExecIDelete() but not easily in the ExecInsert() case,
because ExecInsert() internally searches the correct partition's
resultRelInfo
for an insert and before returning to ExecUpdate resultRelInfo is restored
to the old one.  That's why current logic seems to be reasonable for now.
Is there anything that we can do?

Regards,
Amul

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.