In case you choose to work with a PostgreSQL-driven script application on any of your sites, you should have ample database storage space for it, to guarantee that even if your website grows, it will function smoothly and without any interruptions. Putting more products to an electronic shop or more comments to a community forum are just two instances of what may expand your databases. Should you run out of space at some time, the performance will decrease or the site might not be accessible at all due to the fact that when the storage restriction is reached, the script won't be able to store fresh content in the database - user-generated or system one. Since PostgreSQL is intended for scalable web apps, it is very likely that if you use such a database for your site, you'll need additional space for it as your site grows.