varchar(40) NOT NULL CHECK (name <> '')
);
</programlisting>
  </para>

  <para>
   Create a table with a 2-dimensional array:

<programlisting>
CREATE TABLE array_int (
    vector  int[][]
);
</programlisting>
  </para>

  <para>
   Define a unique table constraint for the table
   <literal>films</literal>.  Unique table constraints can be defined
   on one or more columns of the table:

<programlisting>
CREATE TABLE films (
    code        char(5),
    title       varchar(40),
    did         integer,
    date_prod   date,
    kind        varchar(10),
    len         interval hour to minute,
    CONSTRAINT production UNIQUE(date_prod)
);
</programlisting>
  </para>

  <para>
   Define a check column constraint:

<programlisting>
CREATE TABLE distributors (
    did     integer CHECK (did &gt; 100),
    name    varchar(40)
);
</programlisting>
  </para>

  <para>
   Define a check table constraint:

<programlisting>
CREATE TABLE distributors (
    did     integer,
    name    varchar(40),
    CONSTRAINT con1 CHECK (did &gt; 100 AND name &lt;&gt; '')
);
</programlisting>
  </para>

  <para>
   Define a primary key table constraint for the table
   <structname>films</structname>:

<programlisting>
CREATE TABLE films (
    code        char(5),
    title       varchar(40),
    did         integer,
    date_prod   date,
    kind        varchar(10),
    len         interval hour to minute,
    CONSTRAINT code_title PRIMARY KEY(code,title)
);
</programlisting>
  </para>

  <para>
   Define a primary key constraint for table
   <structname>distributors</structname>.  The following two examples are
   equivalent, the first using the table constraint syntax, the second
   the column constraint syntax:

<programlisting>
CREATE TABLE distributors (
    did     integer,
    name    varchar(40),
    PRIMARY KEY(did)
);

CREATE TABLE distributors (
    did     integer PRIMARY KEY,
    name    varchar(40)
);
</programlisting>
  </para>

  <para>
   Assign a literal constant default value for the column
   <literal>name</literal>, arrange for the default value of column
   <literal>did</literal> to be generated by selecting the next value
   of a sequence object, and make the default value of
   <literal>modtime</literal> be the time at which the row is
   inserted:

<programlisting>
CREATE TABLE distributors (
    name      varchar(40) DEFAULT 'Luso Films',
    did       integer DEFAULT nextval('distributors_serial'),
    modtime   timestamp DEFAULT current_timestamp
);
</programlisting>
  </para>

  <para>
   Define two <literal>NOT NULL</literal> column constraints on the table
   <classname>distributors</classname>, one of which is explicitly
   given a name:

<programlisting>
CREATE TABLE distributors (
    did     integer CONSTRAINT no_null NOT NULL,
    name    varchar(40) NOT NULL
);
</programlisting>
    </para>

    <para>
     Define a unique constraint for the <literal>name</literal> column:

<programlisting>
CREATE TABLE distributors (
    did     integer,
    name    varchar(40) UNIQUE
);
</programlisting>

     The same, specified as a table constraint:

<programlisting>
CREATE TABLE distributors (
    did     integer,
    name    varchar(40),
    UNIQUE(name)
);
</programlisting>
  </para>

  <para>
   Create the same table, specifying 70% fill factor for both the table
   and its unique index:

<programlisting>
CREATE TABLE distributors (
    did     integer,
    name    varchar(40),
    UNIQUE(name) WITH (fillfactor=70)
)
WITH (fillfactor=70);
</programlisting>
  </para>

  <para>
   Create table <structname>circles</structname> with an exclusion
   constraint that prevents any two circles from overlapping:

<programlisting>
CREATE TABLE circles (
    c circle,
    EXCLUDE USING gist (c WITH &amp;&amp;)
);
</programlisting>
  </para>

  <para>
   Create table <structname>cinemas</structname> in tablespace <structname>diskvol1</structname>:

<programlisting>
CREATE TABLE cinemas (
        id serial,
        name text,