Psql is the pgsql's command-line tool. While one can achieve quite a lot with GUI based database management utilities, psql is very useful when one needs to handle database backups, management and alike via scripting. When there is no GUI installed on the server, psql becomes pretty much the only option so it is worth being familiar with it even if you're not a fan.

In order to import the data in psql we will use a COPY command. This requires us to define the data model for the incoming data first.

Defining the table data model from a text file may be prone to errors that will prevent data from being imported. If for of some reason you are not sure what data types are stored in the particular columns of your source file you can import all the data as text and then re-cast it as required at a later time.