Horton

Re: [HACKERS] UPDATE of partition key

David Rowley <david.rowley@2ndquadrant.com>

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From: David Rowley <david.rowley@2ndquadrant.com>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Thomas Munro <thomas.munro@enterprisedb.com>
Date: 2018-01-04T07:54:29Z
Lists: pgsql-hackers 
On 4 January 2018 at 02:52, David Rowley <david.rowley@2ndquadrant.com> wrote:
> I'll try to look at the tests tomorrow and also do some testing. So
> far I've only read the code and the docs.

There are a few more things I noticed on another pass I made today:

20. "carried" -> "carried out the"

+       would have identified the newly updated row and carried
+       <command>UPDATE</command>/<command>DELETE</command> on this new row

21. Extra new line

+   <xref linkend="ddl-partitioning-declarative-limitations">.
+
   </para>

22. In copy.c CopyFrom() you have the following code:

/*
 * We might need to convert from the parent rowtype to the
 * partition rowtype.
 */
map = proute->partition_tupconv_maps[leaf_part_index];
if (map)
{
    Relation partrel = resultRelInfo->ri_RelationDesc;

    tuple = do_convert_tuple(tuple, map);

    /*
    * We must use the partition's tuple descriptor from this
    * point on.  Use a dedicated slot from this point on until
    * we're finished dealing with the partition.
    */
    slot = proute->partition_tuple_slot;
    Assert(slot != NULL);
    ExecSetSlotDescriptor(slot, RelationGetDescr(partrel));
   ExecStoreTuple(tuple, slot, InvalidBuffer, true);
}

Should this use ConvertPartitionTupleSlot() instead?

23. Why write;

last_resultRelInfo = mtstate->resultRelInfo + mtstate->mt_nplans;

when you can write;

last_resultRelInfo = mtstate->resultRelInfo[mtstate->mt_nplans];?


24. In ExecCleanupTupleRouting(), do you think that you could just
have a special case loop for (mtstate && mtstate->operation ==
CMD_UPDATE)?

/*
* If this result rel is one of the UPDATE subplan result rels, let
* ExecEndPlan() close it. For INSERT or COPY, this does not apply
* because leaf partition result rels are always newly allocated.
*/
if (is_update &&
    resultRelInfo >= first_resultRelInfo &&
    resultRelInfo < last_resultRelInfo)
    continue;

Something like:

if (mtstate && mtstate->operation == CMD_UPDATE)
{
    ResultRelInfo *first_resultRelInfo = mtstate->resultRelInfo;
    ResultRelInfo *last_resultRelInfo =
mtstate->resultRelInfo[mtstate->mt_nplans];

    for (i = 0; i < proute->num_partitions; i++)
    {
        ResultRelInfo *resultRelInfo = proute->partitions[i];

        /*
         * Leave any resultRelInfos that belong to the UPDATE's subplan
         * list.  These will be closed during executor shutdown.
         */
        if (resultRelInfo >= first_resultRelInfo &&
            resultRelInfo < last_resultRelInfo)
            continue;

        ExecCloseIndices(resultRelInfo);
        heap_close(resultRelInfo->ri_RelationDesc, NoLock);
    }
}
else
{
    for (i = 0; i < proute->num_partitions; i++)
    {
        ResultRelInfo *resultRelInfo = proute->partitions[i];

        ExecCloseIndices(resultRelInfo);
        heap_close(resultRelInfo->ri_RelationDesc, NoLock);
    }
}

-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

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.