Re: [HACKERS] Parallel Append implementation

On 6 December 2017 at 04:01, Robert Haas <robertmhaas@gmail.com> wrote:
> On Tue, Nov 28, 2017 at 6:02 AM, amul sul <sulamul@gmail.com> wrote:
>> Here are the changes I did on v21 patch to handle crash reported by Rajkumar[1]:
>>
>> diff --git a/src/backend/executor/nodeAppend.c
>> b/src/backend/executor/nodeAppend.c
>> index e3b17cf0e2..e0ee918808 100644
>> --- a/src/backend/executor/nodeAppend.c
>> +++ b/src/backend/executor/nodeAppend.c
>> @@ -479,9 +479,12 @@ choose_next_subplan_for_worker(AppendState *node)
>>             pstate->pa_next_plan = append->first_partial_plan;
>>         else
>>             pstate->pa_next_plan++;
>> -       if (pstate->pa_next_plan == node->as_whichplan)
>> +
>> +       if (pstate->pa_next_plan == node->as_whichplan ||
>> +           (pstate->pa_next_plan == append->first_partial_plan &&
>> +            append->first_partial_plan >= node->as_nplans))
>>         {
>> -           /* We've tried everything! */
>> +           /* We've tried everything or there were no partial plans */
>>             pstate->pa_next_plan = INVALID_SUBPLAN_INDEX;
>>             LWLockRelease(&pstate->pa_lock);
>>             return false;
>
> I changed this around a little, added a test case, and committed this.

Thanks Robert !

The crash that is reported on pgsql-committers, is being discussed on
that list itself.

>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company



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