Brew Package Manager

1. In your command-line run the command: brew install postgres
2. Read the Caveats section that is outputted to the Terminal.
3. Run the command: ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents
4. Open your zsh config file: subl ~/.zshrc
5. At the bottom of the file, create two new aliases to start and stop your postgres server. They could look something like this:

alias pg-start="launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist"
alias pg-stop="launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist"

from the man ln command

The ln utility creates a new directory entry (linked file) which has the same modes as the original file. It is useful for maintaining multiple copies of a file in many places at once without using up storage for the copies''; instead, a link points'' to the original copy. There are two types of links; hard links and symbolic links. How a link ``points'' to a file is one of the differences between a hard and symbolic link.

from the man launchctl command

launchctl interfaces with launchd to manage and inspect daemons, angents and XPC services.