Postgres Process in Kernel Mode?

Started by moisesover 19 years ago5 messages
#1moises
moises@cedaivc.co.cu

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

-

#2Alvaro Herrera
alvherre@commandprompt.com
In reply to: moises (#1)
Re: 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.

#3Chris Browne
cbbrowne@acm.org
In reply to: moises (#1)
Re: Postgres Process in Kernel Mode?

moises@cedaivc.co.cu ("moises") writes:

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<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Hello,<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>I&#8217;m new in postgres SQL and I have some
questions about the space where postgres process run.<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>1-Can any body say me what libs use postgres for make
system calls, for example LIBC? <o:p></o:p></span></font></p>

You can easily determine this yourself using ldd. The answer will
vary depending on what options you use when compiling it.

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>2-Can any body talk me if some postgres process can
run in Linux kernel space? <o:p></o:p></span></font></p>

Yes, it doesn't.

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>3- Some body knows if exist some projects that ports postgres
process on Linux kernel space.<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>I was read some source code of postgres, like, <o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Postgres.C and others&#8230;<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>&nbsp;<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>I was found C instructions like Printf, that&#8217;s prohibitive
for Linux kernel applications, for example in kernel mode we use printk.<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>I suppose that postgres are ported in a user space
only. I&#8217;m Ok?<o:p></o:p></span></font></p>

That's correct.

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Thanks <o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Moises<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>- <o:p></o:p></span></font></p>

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You might want to consider using an email client that doesn't slobber:
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB
style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>
around everywhere.

It's really irritating to have to read around that "deteriorata."
--
(format nil "~S@~S" "cbbrowne" "ntlug.org")
http://www3.sympatico.ca/cbbrowne/advocacy.html
A cool feature of OOP is that the simplest examples are 500 lines.
-- Peter Sestoft

#4Chris Browne
cbbrowne@acm.org
In reply to: moises (#1)
OSCON fallout - Compressed Annealing optimizer

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

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

#5Lexington Luthor
Lexington.Luthor@gmail.com
In reply to: moises (#1)
Re: Postgres Process in Kernel Mode?

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