Horton

Re: UPDATE of partition key

Amit Khandekar <amitdkhan.pg@gmail.com>

View thread View on postgr.es
From: Amit Khandekar <amitdkhan.pg@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-06-09T03:36:20Z
Lists: pgsql-hackers

Attachments

On 7 June 2017 at 20:19, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> On 7 June 2017 at 16:42, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
>> The column bitmap set returned by GetUpdatedColumns() refer to
>> attribute numbers w.r.t. to the root partition. And the
>> mstate->resultRelInfo[] have attnos w.r.t. to the leaf partitions. So
>> we need to do something similar to map_partition_varattnos() to change
>> the updated columns attnos to the leaf partitions
>
> I was wrong about this. Each of the mtstate->resultRelInfo[] has its
> own corresponding RangeTblEntry with its own updatedCols having attnos
> accordingly adjusted to refer its own table attributes. So we don't
> have to do the mapping; we need to get modifedCols separately for each
> of the ResultRelInfo, rather than the root relinfo.
>
>> and walk down the
>> partition constraint expressions to find if the attnos are present
>> there.
>
> But this we will need to do.

Attached is v9 patch. This covers the two parts discussed upthread :
1. Prevent triggers from causing the row movement.
2. Setup the tuple routing in ExecInitModifyTable(), but only if a
partition key is modified. Check new function IsPartitionKeyUpdate().

Have rebased the patch to consider changes done in commit
15ce775faa428dc9 to prevent triggers from violating partition
constraints. There, for the call to ExecFindPartition() in ExecInsert,
we need to fetch the mtstate->rootResultRelInfo in case the operation
is part of update row movement. This is because the root partition is
not available in the resultRelInfo for UPDATE.


Added many more test scenarios in update.sql that cover the above.

I am yet to test the concurrency part using isolation tester.


-- 
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.