<entry></entry>
       <entry>closed geometric path on a plane</entry>
      </row>

      <row>
       <entry><type>real</type></entry>
       <entry><type>float4</type></entry>
       <entry>single precision floating-point number (4 bytes)</entry>
      </row>

      <row>
       <entry><type>smallint</type></entry>
       <entry><type>int2</type></entry>
       <entry>signed two-byte integer</entry>
      </row>

      <row>
       <entry><type>smallserial</type></entry>
       <entry><type>serial2</type></entry>
       <entry>autoincrementing two-byte integer</entry>
      </row>

      <row>
       <entry><type>serial</type></entry>
       <entry><type>serial4</type></entry>
       <entry>autoincrementing four-byte integer</entry>
      </row>

      <row>
       <entry><type>text</type></entry>
       <entry></entry>
       <entry>variable-length character string</entry>
      </row>

      <row>
       <entry><type>time [ (<replaceable>p</replaceable>) ] [ without time zone ]</type></entry>
       <entry></entry>
       <entry>time of day (no time zone)</entry>
      </row>

      <row>
       <entry><type>time [ (<replaceable>p</replaceable>) ] with time zone</type></entry>
       <entry><type>timetz</type></entry>
       <entry>time of day, including time zone</entry>
      </row>

      <row>
       <entry><type>timestamp [ (<replaceable>p</replaceable>) ] [ without time zone ]</type></entry>
       <entry></entry>
       <entry>date and time (no time zone)</entry>
      </row>

      <row>
       <entry><type>timestamp [ (<replaceable>p</replaceable>) ] with time zone</type></entry>
       <entry><type>timestamptz</type></entry>
       <entry>date and time, including time zone</entry>
      </row>

      <row>
       <entry><type>tsquery</type></entry>
       <entry></entry>
       <entry>text search query</entry>
      </row>

      <row>
       <entry><type>tsvector</type></entry>
       <entry></entry>
       <entry>text search document</entry>
      </row>

      <row>
       <entry><type>txid_snapshot</type></entry>
       <entry></entry>
       <entry>user-level transaction ID snapshot (deprecated; see <type>pg_snapshot</type>)</entry>
      </row>

      <row>
       <entry><type>uuid</type></entry>
       <entry></entry>
       <entry>universally unique identifier</entry>
      </row>

      <row>
       <entry><type>xml</type></entry>
       <entry></entry>
       <entry>XML data</entry>
      </row>
     </tbody>
    </tgroup>
   </table>

  <note>
   <title>Compatibility</title>
   <para>
    The following types (or spellings thereof) are specified by
    <acronym>SQL</acronym>: <type>bigint</type>, <type>bit</type>, <type>bit
    varying</type>, <type>boolean</type>, <type>char</type>,
    <type>character varying</type>, <type>character</type>,
    <type>varchar</type>, <type>date</type>, <type>double
    precision</type>, <type>integer</type>, <type>interval</type>,
    <type>numeric</type>, <type>decimal</type>, <type>real</type>,
    <type>smallint</type>, <type>time</type> (with or without time zone),
    <type>timestamp</type> (with or without time zone),
    <type>xml</type>.
   </para>
  </note>

  <para>
   Each data type has an external representation determined by its input
   and output functions.  Many of the built-in types have
   obvious external formats.  However, several types are either unique
   to <productname>PostgreSQL</productname>, such as geometric
   paths, or have several possible formats, such as the date
   and time types.
   Some of the input and output functions are not invertible, i.e.,
   the result of an output function might lose accuracy when compared to
   the original input.
  </para>

  <sect1 id="datatype-numeric">
   <title>Numeric Types</title>

   <indexterm zone="datatype-numeric">
    <primary>data type</primary>
    <secondary>numeric</secondary>
   </indexterm>

   <para>
    Numeric types consist of two-, four-, and eight-byte integers,
    four- and eight-byte