Re: Raw device on PostgreSQL

2020-05-01 Thread Jonah H. Harris
On Fri, May 1, 2020 at 4:59 PM Thomas Munro wrote: > On Fri, May 1, 2020 at 12:28 PM Jonah H. Harris > wrote: > > Also, this will likely have an issue with O_DIRECT as additional buffer > manager alignment is needed and I haven't tracked it down in 13 yet. As my > default development is on a

Re: Raw device on PostgreSQL

2020-05-01 Thread Thomas Munro
On Fri, May 1, 2020 at 12:28 PM Jonah H. Harris wrote: > Also, this will likely have an issue with O_DIRECT as additional buffer > manager alignment is needed and I haven't tracked it down in 13 yet. As my > default development is on a Mac, I have POSIX AIO only. As such, I can't > natively

Re: Raw device on PostgreSQL

2020-05-01 Thread Jose Luis Tallon
On 30/4/20 6:22, Thomas Munro wrote: On Thu, Apr 30, 2020 at 12:26 PM Tomas Vondra wrote: Yeah, I think the question is what are the expected benefits of using raw devices. It might be an interesting exercise / experiment, but my understanding is that most of the benefits can be achieved by

Re: Raw device on PostgreSQL

2020-04-30 Thread Jonah H. Harris
On Wed, Apr 29, 2020 at 8:34 PM Jonah H. Harris wrote: > On Tue, Apr 28, 2020 at 8:10 AM Andreas Karlsson > wrote: > >> To get the performance benefits from using raw devices I think you would >> want to add support for asynchronous IO to PostgreSQL rather than >> implementing your own layer to

Re: Raw device on PostgreSQL

2020-04-29 Thread Thomas Munro
On Thu, Apr 30, 2020 at 12:26 PM Tomas Vondra wrote: > Yeah, I think the question is what are the expected benefits of using > raw devices. It might be an interesting exercise / experiment, but my > understanding is that most of the benefits can be achieved by using file > systems but with direct

Re: Raw device on PostgreSQL

2020-04-29 Thread Tom Lane
Tomas Vondra writes: > Yeah, I think the question is what are the expected benefits of using > raw devices. It might be an interesting exercise / experiment, but my > understanding is that most of the benefits can be achieved by using file > systems but with direct I/O and async I/O, which would

Re: Raw device on PostgreSQL

2020-04-29 Thread Jonah H. Harris
On Tue, Apr 28, 2020 at 8:10 AM Andreas Karlsson wrote: > It would require quite a bit of work since 1) PostgreSQL stores its data > in multiple files and 2) PostgreSQL currently supports only synchronous > buffered IO. > > To get the performance benefits from using raw devices I think you would

Re: Raw device on PostgreSQL

2020-04-29 Thread Tomas Vondra
On Tue, Apr 28, 2020 at 02:10:51PM +0200, Andreas Karlsson wrote: On 4/28/20 10:43 AM, Benjamin Schaller wrote: for an university project I'm currently doing some research on PostgreSQL. I was wondering if hypothetically it would be possible to implement a raw device system to PostgreSQL. I

Re: Raw device on PostgreSQL

2020-04-28 Thread Andreas Karlsson
On 4/28/20 10:43 AM, Benjamin Schaller wrote: for an university project I'm currently doing some research on PostgreSQL. I was wondering if hypothetically it would be possible to implement a raw device system to PostgreSQL. I know that the disadvantages would probably be higher than

Re: Raw device on PostgreSQL

2020-04-28 Thread Stephen Frost
Greetings, * Benjamin Schaller (benjamin.schal...@s2018.tu-chemnitz.de) wrote: > for an university project I'm currently doing some research on PostgreSQL. I > was wondering if hypothetically it would be possible to implement a raw > device system to PostgreSQL. I know that the disa

Raw device on PostgreSQL

2020-04-28 Thread Benjamin Schaller
Hey, for an university project I'm currently doing some research on PostgreSQL. I was wondering if hypothetically it would be possible to implement a raw device system to PostgreSQL. I know that the disadvantages would probably be higher than the advantages compared to working with the file