Horton

Thread

  1. Some items for the TODO list

    Tom Lane <tgl@sss.pgh.pa.us> — 1998-07-08T23:26:09Z

    Things I'd like to see get in there before 6.4:

1. On HPUX, the new no-exec method of starting the backend means that
all the backends claim to be "postmaster"; there's no way to tell 'em
apart via ps(1).  There is some code in postgres.c that tries to update
the process title information by tweaking the original argv[] array, but
that just plain doesn't work under HPUX, nor under quite a few other
Unix variants.  I'm finding out that not being able to tell which
process is which is a real pain in the neck; I don't think it will be
acceptable for production use.  I think we are going to have to bite the
bullet and borrow the process-title-setting code from sendmail --- I
know it's ugly, but it *works* on many many Unixes.

2. I'm starting to get annoyed by the inability to "unlisten" from
a particular relation.  Is there a reason that there is not an UNLISTEN
command?  (Like maybe it's not in ANSI SQL?)  Or is it just something
that never got to the top of the to-do queue?  I see that the low-level
code for a backend to unlisten itself is in there, but there's no way
for the frontend to command it to happen.

If no one else feels like working on these, maybe I will.  I could use
some pointers for #2 though ... what needs to be done to add a new SQL
statement?

			regards, tom lane

  2. Re: [HACKERS] Some items for the TODO list

    ocie@paracel.com — 1998-07-09T01:04:49Z

    Tom Lane wrote:
> 
> Things I'd like to see get in there before 6.4:
> 
> 1. On HPUX, the new no-exec method of starting the backend means that
> all the backends claim to be "postmaster"; there's no way to tell 'em
> apart via ps(1).  There is some code in postgres.c that tries to update
> the process title information by tweaking the original argv[] array, but
> that just plain doesn't work under HPUX, nor under quite a few other
> Unix variants.  I'm finding out that not being able to tell which
> process is which is a real pain in the neck; I don't think it will be
> acceptable for production use.  I think we are going to have to bite the
> bullet and borrow the process-title-setting code from sendmail --- I
> know it's ugly, but it *works* on many many Unixes.
 
One way to tell them apart is to see which of them is the parent of
the rest.  Not as nice as being able to set the title, but it might be
a serviceable workaround in some cases.

Ocie

  3. Re: [HACKERS] Some items for the TODO list

    Thomas Lockhart <lockhart@alumni.caltech.edu> — 1998-07-09T04:41:21Z

    > Is there a reason that there is not an UNLISTEN
> command?  (Like maybe it's not in ANSI SQL?)
> If no one else feels like working on these, maybe I will.  I could use
> some pointers for #2 though ... what needs to be done to add a new SQL
> statement?

I'll add the new statement if you can get the backend to do something
with it. Usually, there is a parse tree structure corresponding to the
command, with any parameters included in it. In this case, the
"unlisten" block should probably look like the "listen" block, since
both probably have similar arguments.

Let me know if you have time to work on it...

                       - Tom

  4. Re: [HACKERS] Some items for the TODO list

    Tom Samplonius <tom@sdf.com> — 1998-07-09T17:48:01Z

    On Wed, 8 Jul 1998, Tom Lane wrote:

> Things I'd like to see get in there before 6.4:
> 
> 1. On HPUX, the new no-exec method of starting the backend means that
> all the backends claim to be "postmaster"; there's no way to tell 'em
> apart via ps(1).  There is some code in postgres.c that tries to update
> the process title information by tweaking the original argv[] array, but
> that just plain doesn't work under HPUX, nor under quite a few other
> Unix variants.  I'm finding out that not being able to tell which
> process is which is a real pain in the neck; I don't think it will be
> acceptable for production use.  I think we are going to have to bite the
> bullet and borrow the process-title-setting code from sendmail --- I
> know it's ugly, but it *works* on many many Unixes.

  Many UNIXes have a setproctitle() function, either in libc or libutil.
I think a native function should be used if exists.

Tom

  5. Re: [HACKERS] Some items for the TODO list

    Bruce Momjian <maillist@candle.pha.pa.us> — 1998-07-09T18:40:07Z

    > 
> On Wed, 8 Jul 1998, Tom Lane wrote:
> 
> > Things I'd like to see get in there before 6.4:
> > 
> > 1. On HPUX, the new no-exec method of starting the backend means that
> > all the backends claim to be "postmaster"; there's no way to tell 'em
> > apart via ps(1).  There is some code in postgres.c that tries to update
> > the process title information by tweaking the original argv[] array, but
> > that just plain doesn't work under HPUX, nor under quite a few other
> > Unix variants.  I'm finding out that not being able to tell which
> > process is which is a real pain in the neck; I don't think it will be
> > acceptable for production use.  I think we are going to have to bite the
> > bullet and borrow the process-title-setting code from sendmail --- I
> > know it's ugly, but it *works* on many many Unixes.
> 
>   Many UNIXes have a setproctitle() function, either in libc or libutil.
> I think a native function should be used if exists.

What is Linux doing with my changes.  Do you see all the process names
as postmaster?  Do you see the query type displayed as part of the ps
output.  We can use setproctitle/sendmail hack to change the process
name from postmaster to postgres, but are these sufficiently quick to
be run for every query to display the query type, i.e. SELECT.

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