Re: Frequent Update Project: Design Overview of HOT Updates

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Frequent Update Project: Design Overview of HOT Updates
Дата
Msg-id 16166.1163136468@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: Frequent Update Project: Design Overview of HOT Updates  ("Pavan Deolasee" <pavan.deolasee@gmail.com>)
Ответы Re: Frequent Update Project: Design Overview of HOT Updates  ("Pavan Deolasee" <pavan.deolasee@gmail.com>)
Список pgsql-hackers
"Pavan Deolasee" <pavan.deolasee@gmail.com> writes:
> On 11/10/06, Josh Berkus <josh@agliodbs.com> wrote:
>> I believe that's the "unsolved technical issue" in the prototype, unless
>> Pavan has solved it in the last two weeks.   Pavan?
>> 
> When an overflow tuple is copied back to the main heap, the overflow tuple
> is
> marked with a special flag (HEAP_OVERFLOW_MOVEDBACK). Subsequently,
> when a backend tries to lock the overflow version of the tuple, it checks
> the flag
> and jumps to the main heap if the flag is set.

(1) How does it "jump to the main heap"?  The links go the other
direction.

(2) Isn't this full of race conditions?

(3) I thought you already used up the one remaining t_infomask bit.
        regards, tom lane


В списке pgsql-hackers по дате отправления:

Предыдущее
От: "Pavan Deolasee"
Дата:
Сообщение: Re: Frequent Update Project: Design Overview of HOT Updates
Следующее
От: "Pavan Deolasee"
Дата:
Сообщение: Re: Frequent Update Project: Design Overview of HOT Updates