When upgrading or installing recent versions of the postgres ruby gem on Leopard the following error appears

	===========   WARNING   ===========

		You are building this extension on OS X without setting the
		ARCHFLAGS environment variable, and PostgreSQL does not appear
		to have been built as a universal binary. If you are seeing this
		message, that means that the build will probably fail.

		Try setting the environment variable ARCHFLAGS
		to '-arch i386' before building.

		For example:
		(in bash) $ export ARCHFLAGS='-arch i386'
		(in tcsh) $ setenv ARCHFLAGS '-arch i386'

		Then try building again.

		===================================

The trick is to set the ARCHFLAGS variable inside the sudo command using env.

sudo env ARCHFLAGS="-arch i386" gem install postgres

Dump, bzip, and upload a postgres database to strongspace. Via Ubernostrum

#!/usr/bin/bash

FILENAME=b_list-`/usr/xpg4/bin/date +%Y%m%d`.sql.bz2
cd /home/myuser/dumps
/opt/local/bin/pg_dump -U db_username db_name | /usr/bin/bzip2 > $FILENAME
/usr/bin/scp $FILENAME me@strongspace:/my/backup/dir/

Connecting R to Postgres on OS X is a little bit of a hassle given where OS X looks for the libraries to link to.

Assuming you've installed Postgres via MacPorts, add shell variables for your Postgres lib and include directories to ~/.profile

export PG_LIB_DIR=/opt/local/lib/postgresql82
export PG_INCLUDE_DIR=/opt/local/include/postgresql82

Add a link from the OS X SDK directory to /opt

$ sudo ln -s /opt/ /Developer/SDKs/MacOSX10.4u.sdk/opt

Then install RdbiPgSQL as you would normally.

If the install fails because R isn't picking up the PG_LIB_DIR, _INCLUDE_DIR variables, keep a lookout for the lines in the install error output that look like

The downloaded packages are in
	/tmp/RtmpTakYpZ/downloaded_packages

In Terminal, change to this directory, replacing the 'RtmpTakYpZ' string with whatever directory the error output gives. Then run the R install command on the package file:

$ cd /tmp/RtmpTakYpZ/downloaded_packages
$ sudo R CMD INSTALL RdbiPgSQL_1.10.0.tar.gz 

Enable or disable the automatic launch of the postgresql server installed via macports. Starts or stops the daemon and modifies the launchd manifest.

launchctl load -w /opt/local/etc/LaunchDaemons/org.darwinports.postgresql81-server/org.darwinports.postgresql81-server.plist

launchctl unload -w /opt/local/etc/LaunchDaemons/org.darwinports.postgresql81-server/org.darwinports.postgresql81-server.plist

Postgres was installed through darwinports, so

/opt/local/lib/postgresql81/bin/pg_ctl -D /opt/local/var/db/postgresql81/defaultdb/ start