Re: Limiting setting of hint bits by read-only queries; vacuum_delay
От | Greg Stark |
---|---|
Тема | Re: Limiting setting of hint bits by read-only queries; vacuum_delay |
Дата | |
Msg-id | CAM-w4HMoCsvKQhaJwOzvdY=x30hkYNaqj3vKwcmg-YmKZRF+Ug@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Limiting setting of hint bits by read-only queries; vacuum_delay (Kevin Grittner <kgrittn@ymail.com>) |
Ответы |
Re: Limiting setting of hint bits by read-only queries; vacuum_delay
Re: Limiting setting of hint bits by read-only queries; vacuum_delay |
Список | pgsql-hackers |
On Mon, Mar 25, 2013 at 9:53 PM, Kevin Grittner <kgrittn@ymail.com> wrote: > That would make it harder to construct a degenerate case I don't think it's hard at all. It's the same as the case Simon wants to solve except that the cost is incurred in a different way. Imagine a system where there's a huge data load to a table which is then read-only for an OLTP system. Until vacuum comes along -- and it may never since the table never sees deletes or updates -- every transaction needs to do a clog lookup for every tuple it sees. That means a significant cpu slowdown for every row lookup forever more. To save a one-time i/o cost. -- greg
В списке pgsql-hackers по дате отправления: