I just installed PostgreSQL on Mac OS X 10.4 Tiger, and found that the PostgreSQL StartupItem provided in the acs-core-docs no longer works.  Instead use Tiger's Launchd system, which is so much simpler than StartupItems in previous Mac OS X releases.

Creating a PostgreSQL Launchd file allows your system to start up postmaster when your Mac boots.

This tip shows you how to create this file.

Use a text editor such as emacs to create the PostgreSQL Launchd file:

$ emacs /Library/LaunchDaemons/org.postgresql.PostgreSQL.plist

Copy and paste the following into the file.

################# COPY BELOW ###########################
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>Label</key>
        <string>org.postgresql.PostgreSQL</string>
        <key>OnDemand</key>
        <false/>
        <key>ProgramArguments</key>
        <array>
            <string>/usr/local/pgsql/bin/pg_ctl</string>
            <string>-D</string>
            <string>/usr/local/pgsql/data</string>
            <string>-l</string>
            <string>/usr/local/pgsql/data/server.log</string>
            <string>start</string>
        </array>
        <key>ServiceDescription</key>
        <string>PostgreSQL Server</string>
        <key>UserName</key>
        <string>postgres</string>
        <key>GroupName</key>
        <string>web</string>
    </dict>
</plist>
################# COPY BELOW ###########################

Next reboot your Mac and check to see if postmaster started up.

Or you can try the following commands:

$ sudo launchctl load /Library/LaunchDaemons/org.postgresql.PostgreSQL.plist
$ sudo launchctl start org.postgresql.PostgreSQL