What is the difference between the postmaster binary and the postgres
binary?  Does the postmaster act as nothing more than a multiplexor for
postgres processes or something?

Chris


Wed, 9 Jan 2002 13:38:21 +0800
"Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
postmaster vs. postgres
"Christopher Kings-Lynne" <chriskl@familyhealth.com.au> writes:
> What is the difference between the postmaster binary and the postgres
> binary?  Does the postmaster act as nothing more than a multiplexor for
> postgres processes or something?

None, and yup.  There is some stuff about this at
http://developer.postgresql.org/osdn.php (I recommend the "tour"
slides ;-)).  I thought we had some graphics about this in the standard
documentation, too, but am not finding it right now.

			regards, tom lane

Wed, 09 Jan 2002 01:03:13 -0500
Tom Lane <tgl@sss.pgh.pa.us>
Re: postmaster vs. postgres 
Christopher Kings-Lynne wrote:
> What is the difference between the postmaster binary and the postgres
> binary?  Does the postmaster act as nothing more than a multiplexor for
> postgres processes or something?

The binaries are the same -- one is a symlink to the other.  This allows
us to fork postgres children of the postmaster with no exec().  The
binary does read argv[0] and behaves differently depending on which
binary name it was called under.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Wed, 9 Jan 2002 01:07:34 -0500 (EST)
Bruce Momjian <pgman@candle.pha.pa.us>
Re: postmaster vs. postgres
On Wed, 9 Jan 2002, Christopher Kings-Lynne wrote:

> What is the difference between the postmaster binary and the postgres
> binary?  Does the postmaster act as nothing more than a multiplexor for
> postgres processes or something?

The postmaster 'binary' is a symbolic link to postgres. In reality, the
naming convention corresponds programmatically to what you have
described. If the invokation is done via 'postmaster' PostmasterMain() is
executed, otherwise it is assumed that a standalone backend s executed.

Gavin



Wed, 9 Jan 2002 17:13:04 +1100 (EST)
Gavin Sherry <swm@linuxworld.com.au>
Re: postmaster vs. postgres