Re: Index scan prefetch?

2018-03-27 Thread konstantin knizhnik
On Mar 26, 2018, at 10:59 PM, Justin Pryzby wrote: > On Mon, Mar 26, 2018 at 12:43:02PM +0300, Konstantin Knizhnik wrote: >> Hi, hackers. >> >> I was faced with the following bad performance use case with Postgres: there >> is a huge append-only table with serial key (ID) >> which is

Re: Index scan prefetch?

2018-03-26 Thread Claudio Freire
On Mon, Mar 26, 2018 at 4:59 PM, Justin Pryzby wrote: >> But now effective_io_concurrency parameter is applicable only for bitmap > ... >> Will it be useful to support it also for index scan? >> Or there are some other ways to address this problem? > > Does your case perform

Re: Index scan prefetch?

2018-03-26 Thread Justin Pryzby
On Mon, Mar 26, 2018 at 12:43:02PM +0300, Konstantin Knizhnik wrote: > Hi, hackers. > > I was faced with the following bad performance use case with Postgres: there > is a huge append-only table with serial key (ID) > which is permanently appended using multithreaded pgloader. I think this could

Index scan prefetch?

2018-03-26 Thread Konstantin Knizhnik
Hi, hackers. I was faced with the following bad performance use case with Postgres: there is a huge append-only table with serial key (ID) which is permanently appended using multithreaded pgloader. Ideally (if there is no parallel load), this table should be clustered by "ID" key: records