Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Поиск
Список
Период
Сортировка
От Zhihong Yu
Тема Re: Add SPLIT PARTITION/MERGE PARTITIONS commands
Дата
Msg-id CALNJ-vTmPOOS2U-eL45gDgfxf+Z29+vJo1g8XaJPu5u7CFz62w@mail.gmail.com
обсуждение исходный текст
Ответ на Re: Add SPLIT PARTITION/MERGE PARTITIONS commands  (Dmitry Koval <d.koval@postgrespro.ru>)
Список pgsql-hackers


On Wed, Jun 1, 2022 at 11:58 AM Dmitry Koval <d.koval@postgrespro.ru> wrote:
Hi,

1)
> For attachPartTable, the parameter wqueue is missing from comment.
> The parameters of CloneRowTriggersToPartition are called parent and partition.
> I think it is better to name the parameters to attachPartTable in a similar manner.
>
> For struct SplitPartContext, SplitPartitionContext would be better name.
>
> +       /* Store partition contect into list. */
> contect -> context

Thanks, changed.

2)
> For transformPartitionCmdForMerge(), nested loop is used to detect duplicate names.
> If the number of partitions in partcmd->partlist, we should utilize map to speed up the check.

I'm not sure what we should utilize map in this case because chance that
number of merging partitions exceed dozens is low.
Is there a function example that uses a map for such a small number of
elements?

3)
> For check_parent_values_in_new_partitions():
>
> +           if (!find_value_in_new_partitions(&key->partsupfunc[0],
> +                                             key->partcollation, parts, nparts, datum, false))
> +               found = false;
>
> It seems we can break out of the loop when found is false.

We have implicit "break" in "for" construction:

+       for (i = 0; i < boundinfo->ndatums && found; i++)

I'll change it to explicit "break;" to avoid confusion.


Attached patch with the changes described above.
--
With best regards,
Dmitry Koval

Postgres Professional: http://postgrespro.com
Hi,
Thanks for your response. 

w.r.t. #2, I think using nested loop is fine for now.
If, when this feature is merged, some user comes up with long merge list, we can revisit this topic.

Cheers

В списке pgsql-hackers по дате отправления:

Предыдущее
От: Dmitry Koval
Дата:
Сообщение: Re: Add SPLIT PARTITION/MERGE PARTITIONS commands
Следующее
От: Robert Haas
Дата:
Сообщение: Re: Ignoring BRIN for HOT udpates seems broken