pg_connect options

[togno]

After hours of searching WHAT are the possible options to pass with a connection to PostgreSQL db, I only found people like me. They are complaining about lack of documentation for these options (description, syntax).

• pg_connect documentation says nothing.

• man postgres says :
  "Some of the switches explained in this man page can be passed to the backend through the "database options" field of a connection request"
  Ho, great ...
  (very frustrating indeed)

• man libpq is no nore helpfull.

• PostgreSQL book (the one on PostreSQL.org) do not bother to document this.

  So, is the documentation hidden in a armored chest, hidden somewhere near south pole ? 😉

  By the way, the reason of this is that I have a certain db query that is far more used that the others. So I would like to execute it in no-fsync mode. So I would like to pass the no-fsync argument to my connection request, if possible.
  Thank you

[smarlowe]

Try this:

www.php.net/pg_connect

[smarlowe]

Those options are generally used to send debug and trace options to the backend, so it's probably of limited use to anyone who doesn't hack the postgres backend.

[togno]

yeah, i've also read that (in libpq documentation), BUT:
when you read the backend server manual page (man postgre), it says that:

<< Some of the switches explained in this man page can be passed to the backend through the "database options" field of a connection request [...] This is particularly handy for debugging-related switches.>>

all right ?
sadly, they didn't explain wich ones, nor the exact syntax. AND they do not say that the only switches concerned are the debug/trace ones. So you could think of other interesting options to pass whith the connection request.

For example, there is the -F switch 🙂 (no-fsync).
There is also the interesting -B switch (dealing whith memory)

I'm convinced that no one knows nothing about this mysterious option field. Booooooo ;(
(no-one but PostgreSQL hackers of course)

[Anon]

OK, so you forced me to look it up in the source, and, viola, in
src/postgresql-snapshot/src/backend/postmaster/postmaster.c it says:

/
Set by the -o option
*/
static char ExtraOptions[MAXPGPATH];

/
These globals control the behavior of the postmaster in case some
backend dumps core. Normally, it kills all peers of the dead backend
and reinitializes shared memory. By specifying -s or -n, we can have
the postmaster stop (rather than kill) peers and not reinitialize
shared data structures.
*/

A few dozen paragraphs later it explains every single switch, in detail.

[togno]

Hehe
You're right, the source is the ultimate documentation of a program. Thanks to have looked it up.
I'm just a bit disapointed that apparently we cannot specify a no-fsync behavior just for certain connections. Those who are less vital but more frequent.
I'll look it up more accuratly thanks to your hint.
thanks for all.

Togno