from operating system user accounts.  When you connect to a
      database, you can choose what
      <productname>PostgreSQL</productname> user name to connect as;
      if you don't, it will default to the same name as your current
      operating system account.  As it happens, there will always be a
      <productname>PostgreSQL</productname> user account that has the
      same name as the operating system user that started the server,
      and it also happens that that user always has permission to
      create databases.  Instead of logging in as that user you can
      also specify the <option>-U</option> option everywhere to select
      a <productname>PostgreSQL</productname> user name to connect as.
     </para>
    </footnote>
   </para>

   <para>
    You can also create databases with other names.
    <productname>PostgreSQL</productname> allows you to create any
    number of databases at a given site.  Database names must have an
    alphabetic first character and are limited to 63 bytes in
    length.  A convenient choice is to create a database with the same
    name as your current user name.  Many tools assume that database
    name as the default, so it can save you some typing.  To create
    that database, simply type:
<screen>
<prompt>$</prompt> <userinput>createdb</userinput>
</screen>
   </para>

   <para>
    If you do not want to use your database anymore you can remove it.
    For example, if you are the owner (creator) of the database
    <literal>mydb</literal>, you can destroy it using the following
    command:
<screen>
<prompt>$</prompt> <userinput>dropdb mydb</userinput>
</screen>
    (For this command, the database name does not default to the user
    account name.  You always need to specify it.)  This action
    physically removes all files associated with the database and
    cannot be undone, so this should only be done with a great deal of
    forethought.
   </para>

   <para>
    More about <command>createdb</command> and <command>dropdb</command> can
    be found in <xref linkend="app-createdb"/> and <xref linkend="app-dropdb"/>
    respectively.
   </para>
  </sect1>


  <sect1 id="tutorial-accessdb">
   <title>Accessing a Database</title>

   <indexterm zone="tutorial-accessdb">
    <primary>psql</primary>
   </indexterm>

   <para>
    Once you have created a database, you can access it by:

    <itemizedlist spacing="compact" mark="bullet">
     <listitem>
      <para>
       Running the <productname>PostgreSQL</productname> interactive
       terminal program, called <application><firstterm>psql</firstterm></application>, which allows you
       to interactively enter, edit, and execute
       <acronym>SQL</acronym> commands.
      </para>
     </listitem>

     <listitem>
      <para>
       Using an existing graphical frontend tool like
       <application>pgAdmin</application> or an office suite with
       <acronym>ODBC</acronym> or <acronym>JDBC</acronym> support to create and manipulate a
       database.  These possibilities are not covered in this
       tutorial.
      </para>
     </listitem>

     <listitem>
      <para>
       Writing a custom application, using one of the several
       available language bindings.  These possibilities are discussed
       further in <xref linkend="client-interfaces"/>.