Re: Clock sweep not caching enough B-Tree leaf pages?
| От | Jason Petersen |
|---|---|
| Тема | Re: Clock sweep not caching enough B-Tree leaf pages? |
| Дата | |
| Msg-id | 5D48DA93-F622-4DA3-B9A3-2D5FB0AAD329@citusdata.com обсуждение исходный текст |
| Ответ на | Re: Clock sweep not caching enough B-Tree leaf pages? (Atri Sharma <atri.jiit@gmail.com>) |
| Ответы |
Re: Clock sweep not caching enough B-Tree leaf pages?
Re: Clock sweep not caching enough B-Tree leaf pages? Re: Clock sweep not caching enough B-Tree leaf pages? |
| Список | pgsql-hackers |
On Apr 18, 2014, at 1:51 PM, Atri Sharma <atri.jiit@gmail.com> wrote:
Yes, we obviously want a virtual clock. Focusing on the use of gettimeofday seems silly to me: it was something quick for the prototype.
Counting clock sweeps is an intersting idea. I think one concern was
tracking hot buffers in cases where there is no memory pressure, and
hence the clock sweep isn't running --- I am not sure how this would
help in that case.
The problem with the clocksweeps is they don’t actually track the progression of “time” within the PostgreSQL system.
What’s wrong with using a transaction number or some similar sequence? It would accurately track “age” in the sense we care about: how long ago in “units of real work being done by the DB” something was added.
—Jason
В списке pgsql-hackers по дате отправления: