Re: [HACKERS] GSoC 2017: weekly progress reports (week 6)

Поиск
Список
Период
Сортировка
От Teodor Sigaev
Тема Re: [HACKERS] GSoC 2017: weekly progress reports (week 6)
Дата
Msg-id 0c8b3c0d-17a6-6406-bbe8-752cad2298db@sigaev.ru
обсуждение исходный текст
Ответ на Re: [HACKERS] GSoC 2017: weekly progress reports (week 6)  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
Список pgsql-hackers

Alvaro Herrera wrote:
> Heikki Linnakangas wrote:
> 
>> Remember, the purpose of predicate locks is to lock key ranges, not physical
>> pages or tuples in the index. We use leaf pages as handy shortcut for "any
>> key value that would belong on this page", but it is just an implementation
>> detail.
> 
> Hmm ... so, thinking about pending list locking, would it work to
> acquire locks on the posting tree's root of each item in the pending
> list, when the item is put in the pending list? (even if we insert the
> item in the pending list instead of its posting tree).

Items in pending list doesn't use posting tree or list, pending list is just 
list of pair (ItemPointer to heap, entry) represented as IndexTuple. There is no 
order in pending list, so Heikki suggests to lock metapage always instead of 
locking whole relation if fastupdate=on. If fastupdate is off then insertion 
process will not change metapage.

-- 
Teodor Sigaev                                   E-mail: teodor@sigaev.ru
                                                    WWW: http://www.sigaev.ru/


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Andrey Borodin
Дата:
Сообщение: Re: [HACKERS] GSoC 2017: weekly progress reports (week 6)
Следующее
От: Tom Lane
Дата:
Сообщение: Re: Transform for pl/perl