Re: Compressed TOAST Slicing

Поиск
Список
Период
Сортировка
От Paul Ramsey
Тема Re: Compressed TOAST Slicing
Дата
Msg-id CACowWR0pUkSbzkGz9-DowbcixdiPVdkpwjc_U08um+H2kdc6Fg@mail.gmail.com
обсуждение исходный текст
Ответ на Re: Compressed TOAST Slicing  (Simon Riggs <simon@2ndquadrant.com>)
Ответы Re: Compressed TOAST Slicing  (Юрий Соколов <funny.falcon@gmail.com>)
Re: Compressed TOAST Slicing  (Simon Riggs <simon@2ndquadrant.com>)
Re: Compressed TOAST Slicing  ("Daniel Verite" <daniel@manitou-mail.org>)
Список pgsql-hackers
On Sat, Feb 16, 2019 at 7:25 AM Simon Riggs <simon@2ndquadrant.com> wrote:

> Could we get an similarly optimized implementation of -> operator for JSONB as well?
> Are there any other potential uses? Best to fix em all up at once and then move on to other things. Thanks.

Oddly enough, I couldn't find many/any things that were sensitive to
left-end decompression. The only exception is "LIKE this%" which
clearly would be helped, but unfortunately wouldn't be a quick
drop-in, but a rather major reorganization of the regex handling.

I had a look at "->" and I couldn't see how a slice could be used to
make it faster? We don't a priori know how big a slice would give us
what we want. This again makes Stephen's case for an iterator, but of
course all the iterator benefits only come when the actual function at
the top (in this case the json parser) are also updated to be
iterative.

Committing this little change doesn't preclude an iterator, or even
make doing one more complicated... :)

P.


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Thomas Munro
Дата:
Сообщение: Re: Some thoughts on NFS
Следующее
От: Tom Lane
Дата:
Сообщение: More smarts about CoerceViaIO, and less stupidity about ArrayCoerceExpr