test_munge();
</programlisting>
    </para>
    </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      <literal><function>spi_query(<replaceable>command</replaceable>)</function></literal>
      <indexterm>
       <primary>spi_query</primary>
       <secondary>in PL/Perl</secondary>
      </indexterm>
     </term>
     <term>
      <literal><function>spi_fetchrow(<replaceable>cursor</replaceable>)</function></literal>
      <indexterm>
       <primary>spi_fetchrow</primary>
       <secondary>in PL/Perl</secondary>
      </indexterm>
     </term>
     <term>
      <literal><function>spi_cursor_close(<replaceable>cursor</replaceable>)</function></literal>
      <indexterm>
       <primary>spi_cursor_close</primary>
       <secondary>in PL/Perl</secondary>
      </indexterm>
     </term>

    <listitem>
    <para>
    <literal>spi_query</literal> and <literal>spi_fetchrow</literal>
    work together as a pair for row sets which might be large, or for cases
    where you wish to return rows as they arrive.
    <literal>spi_fetchrow</literal> works <emphasis>only</emphasis> with
    <literal>spi_query</literal>. The following example illustrates how
    you use them together:

<programlisting>
CREATE TYPE foo_type AS (the_num INTEGER, the_text TEXT);

CREATE OR REPLACE FUNCTION lotsa_md5 (INTEGER) RETURNS SETOF foo_type AS $$
    use Digest::MD5 qw(md5_hex);
    my $file = '/usr/share/dict/words';
    my $t = localtime;
    elog(NOTICE, "opening file $file at $t" );
    open my $fh, '&lt;', $file # ooh, it's a file access!
        or elog(ERROR, "cannot open $file for reading: $!");
    my @words = &lt;$fh&gt;;
    close $fh;
    $t = localtime;
    elog(NOTICE, "closed file $file at $t");
    chomp(@words);
    my $row;
    my $sth = spi_query("SELECT * FROM generate_series(1,$_[0]) AS b(a)");
    while (defined ($row = spi_fetchrow($sth))) {
        return_next({
            the_num =&gt; $row-&gt;{a},
            the_text =&gt; md5_hex($words[rand @words])
        });
    }
    return;
$$ LANGUAGE plperlu;

SELECT * from lotsa_md5(500);
</programlisting>
    </para>

    <para>
     Normally, <function>spi_fetchrow</function> should be repeated until it
     returns <literal>undef</literal>, indicating that there are no more
     rows to read.  The cursor returned by <literal>spi_query</literal>
     is automatically freed when
     <function>spi_fetchrow</function> returns <literal>undef</literal>.
     If you do not wish to read all the rows, instead call
     <function>spi_cursor_close</function> to free the cursor.
     Failure to do so will result in memory leaks.
    </para>

    </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      <literal><function>spi_prepare(<replaceable>command</replaceable>, <replaceable>argument types</replaceable>)</function></literal>
      <indexterm>
       <primary>spi_prepare</primary>
       <secondary>in PL/Perl</secondary>
     </indexterm>
     </term>
     <term>
      <literal><function>spi_query_prepared(<replaceable>plan</replaceable>, <replaceable>arguments</replaceable>)</function></literal>
      <indexterm>
       <primary>spi_query_prepared</primary>
       <secondary>in PL/Perl</secondary>
      </indexterm>
     </term>
     <term>
      <literal><function>spi_exec_prepared(<replaceable>plan</replaceable> [, <replaceable>attributes</replaceable>], <replaceable>arguments</replaceable>)</function></literal>
      <indexterm>
       <primary>spi_exec_prepared</primary>
       <secondary>in PL/Perl</secondary>
      </indexterm>
     </term>
     <term>
      <literal><function>spi_freeplan(<replaceable>plan</replaceable>)</function></literal>
      <indexterm>
       <primary>spi_freeplan</primary>
       <secondary>in PL/Perl</secondary>
      </indexterm>
     </term>

    <listitem>
    <para>
    <literal>spi_prepare</literal>, <literal>spi_query_prepared</literal>, <literal>spi_exec_prepared</literal>,
    and <literal>spi_freeplan</literal> implement