Starting a Database Session

POSTGRESQL uses a client/server  model of communication. A POSTGRESQL server is continually running, waiting for client requests. The server processes the request and returns the result to the client.

Choosing an Interface

Because the POSTGRESQL server runs as an independent process on the computer, a user cannot interact with it directly. Instead, client applications have been designed specifically for user interaction. This chapter describes how to interact with POSTGRESQL using the psql  client application. Additional interfaces are covered in Chapters  and .

Choosing a Database

Each POSTGRESQL server controls access to a number of databases. Databases are storage areas used by the server to partition information. For example, a typical installation may have a production database, used to keep all information about a company. It may also have a training database, used for training and testing purposes. They may have private databases, used by individuals to store personal information. For this exercise, we will assume that you have created an empty database called test. If not, see Appendix .

Starting a Session

To start a psql session and connect to the test database, type psql test at the command prompt. Your output should look similar to Figure . Remember, the operating system command prompt is case-sensitive, so you must type this in all lowercase.^7.1  

        $ psql test
        Welcome to psql, the PostgreSQL interactive terminal. 
         
        Type:  \copyright for distribution terms
               \h for help with SQL commands
               \? for help on internal slash commands
               \g or terminate with semicolon to execute query
               \q to quit 
         
        test=>