One of the most important things to consider when creating and using a database is how to organize the data. The layout of the database should be decided when you first establish the database. The layout can be decided or changed at a later date, but this is almost guaranteed to be a tedious, if not difficult, task. If it is never decided, a database will become disorganized over time and introduce significant hurdles when upgrading components or running backups.

By default, a new PostgreSQL database has only one schema, that is, public. Most users place all the data (their own and third-party modules such as PostGIS) in the public schema. Doing so mixes information of different origins. An easy method to separate the information is to use schemas. This enables using one schema for our data and a separate schema for everything else.