Re: Needless additional partition check in INSERT?

Amit Khandekar <amitdkhan.pg@gmail.com>

From: Amit Khandekar <amitdkhan.pg@gmail.com>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Simon Riggs <simon@2ndquadrant.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Amit Langote <amitlangote09@gmail.com>
Date: 2018-05-11T09:43:03Z
Lists: pgsql-hackers
On 11 May 2018 at 14:50, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> On 10 May 2018 at 15:26, David Rowley <david.rowley@2ndquadrant.com> wrote:
>> Yeah, the comments do need work. In order to make it a bit easier to
>> document I changed the way that check_partition_constr is set. This is
>> now done with an if/else if/else clause for both COPY and INSERT.
>>
>> Hopefully, that's easier to understand and prevents further mistakes.
>>
>> Patch attached.
>
> The patch looks good in terms of handling the redundant constraint check.
>
> Since this patch also does some minor code restructuring with the if
> conditions, below are some comments on them :
>
> With the patch, the if condition uses ri_PartitionCheck, and further
> ExecConstraints() also uses ri_PartitionCheck to decide whether to
> call ExecPartitionCheck(). So instead, if we just don't bother about
> ri_PartitionCheck outside ExecConstraints() and let ExecConstraints()
> handle it, then the if conditions would get simpler :
>
> if (resultRelInfo->ri_PartitionRoot == NULL ||
>     (resultRelInfo->ri_TrigDesc &&
>      resultRelInfo->ri_TrigDesc->trig_insert_before_row))
>    check_partition_constr = true;
> else
>    check_partition_constr = false;

This looks better (it will avoid unnecessary ExecConstraints() call) :

if (resultRelInfo->ri_PartitionRoot == NULL ||
     (resultRelInfo->ri_TrigDesc &&
      resultRelInfo->ri_TrigDesc->trig_insert_before_row))
    check_partition_constr = resultRelInfo->ri_PartitionCheck;
else
   check_partition_constr = false;

>
> --
> Thanks,
> -Amit Khandekar
> EnterpriseDB Corporation
> The Postgres Database Company



-- 
Thanks,
-Amit Khandekar
EnterpriseDB Corporation
The Postgres Database Company


Commits

  1. Don't needlessly check the partition contraint twice