Обсуждение: Postgres Process in Kernel Mode?

moises wrote:

> 1-Can any body say me what libs use postgres for make system calls, for
> example LIBC? 

libc and a lot others.

> 2-Can any body talk me if some postgres process can run in Linux kernel
> space? 

No.

> 3- Some body knows if exist some projects that ports postgres process on
> Linux kernel space.

No that we've heard lately.  (But I remember a guy with a .cu domain
asking not long ago, maybe it was you.)

> I was found C instructions like Printf, that's prohibitive for Linux kernel
> applications, for example in kernel mode we use printk.

That's because Postgres is a user-space program and there are no
intentions to change that.

> I suppose that postgres are ported in a user space only. I'm Ok?

Yes.

If you prefer spanish, I suggest you subscribe to the pgsql-es-ayuda
list.  There is at least one Postgres hacker there.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.

Robert Hansen did a talk at OSCON on a compressed annealing framework
called Djinni: <http://sixdemonbag.org/Djinni/>

It's a framework to use compressed annealing (a derivative of
simulated annealing) for finding approximate solutions to NP-complete
problems such as the TSP with time windows.  Note that while Djinni is
implemented in C++, it already supports embedding via SWIG, and has a
C wrapper and is accessible from other languages.  And it's
BSD-licensed...

This has the potential to be an alternative to the present use of GEQO
for query optimization for cases of large joins (e.g. - involving
large numbers of tables).

On the one hand, I'm somewhat suited to looking at this in that I have
the operations research background to know what they're talking about.
On the other hand, I'm not familiar with the optimizer, nor do I deal
with sorts of cases with so many joins that this would be worthwhile.

I've bounced a ToDo entry over to Bruce, and am making sure this is
documented here on pgsql.hackers so that a web search can readily find
it in the future...
-- 
"cbbrowne","@","cbbrowne.com"
http://www3.sympatico.ca/cbbrowne/
"It is far from complete, but it  should explain enough that you don't
just stare at your sendmail.cf file like a deer staring at an oncoming
truck."  -- David Charlap

moises wrote:
> Hello,
> 
> I’m new in postgres SQL and I have some questions about the space where 
> postgres process run.
> 
> 1-Can any body say me what libs use postgres for make system calls, for 
> example LIBC?
> 
> 2-Can any body talk me if some postgres process can run in Linux kernel 
> space?
> 
> 3- Some body knows if exist some projects that ports postgres process on 
> Linux kernel space.
>  
> 
> I was read some source code of postgres, like,
> 
> Postgres.C and others…
> 
> I was found C instructions like Printf, that’s prohibitive for Linux 
> kernel applications, for example in kernel mode we use printk.
> 
> I suppose that postgres are ported in a user space only. I’m Ok?
>  
> 
> Thanks
> 
> Moises


You can do it (e.g. http://www.yl.is.s.u-tokyo.ac.jp/~tosh/kml/) but why 
would you want to? PG runs fine in userspace and I can see no particular 
benefit to being in the kernel.

What exactly are you trying to do with it? Are you trying to interface 
PG with some kernel facility?


LL