Re: [PATCH] Compression dictionaries for JSONB

Поиск
Список
Период
Сортировка
От Nikita Malakhov
Тема Re: [PATCH] Compression dictionaries for JSONB
Дата
Msg-id CAN-LCVMPyTR_-R94RBvhA2er+4McDHWn8TiFVZBT-AdeFrodJw@mail.gmail.com
обсуждение исходный текст
Ответ на Re: [PATCH] Compression dictionaries for JSONB  (Aleksander Alekseev <aleksander@timescale.com>)
Ответы Re: [PATCH] Compression dictionaries for JSONB  (Aleksander Alekseev <aleksander@timescale.com>)
Список pgsql-hackers
Hi hackers!

Aleksander, please point me in the right direction if it was mentioned before, I have a few questions:

1) It is not clear for me, how do you see the life cycle of such a dictionary? If it is meant to keep growing without 
cleaning up/rebuilding it could affect performance in an undesirable way, along with keeping unused data without 
any means to get rid of them.
Also, I agree with Simon Riggs, using OIDs from the general pool for dictionary entries is a bad idea.

2) From (1) follows another question - I haven't seen any means for getting rid of unused keys (or any other means 
for dictionary cleanup). How could it be done?

3) Is the possible scenario legal - by some means a dictionary does not contain some keys for entries? What happens then?

4) If one dictionary is used by several tables - I see future issues in concurrent dictionary updates. This will for sure
affect performance and can cause unpredictable behavior for queries.

If you have any questions on Pluggable TOAST don't hesitate to ask me and on JSONB Toaster you can ask Nikita Glukhov. 

Thank you!

Regards,
Nikita Malakhov
Postgres Professional 
On Mon, Jul 11, 2022 at 6:41 PM Aleksander Alekseev <aleksander@timescale.com> wrote:
Hi hackers,

> I invite anyone interested to join this effort as a co-author!

Here is v5. Same as v4 but with a fixed compiler warning (thanks,
cfbot). Sorry for the noise.

--
Best regards,
Aleksander Alekseev

В списке pgsql-hackers по дате отправления:

Предыдущее
От: Aleksander Alekseev
Дата:
Сообщение: Re: CREATE TABLE ( .. STORAGE ..)
Следующее
От: Alexander Korotkov
Дата:
Сообщение: Re: POC: Lock updated tuples in tuple_update() and tuple_delete()