LongReadLen (unsigned integer, inherited)

This attribute may be used to control the maximum
length of 'long' ('blob', 'memo' etc.) fields which
the driver will read from the database automatically
when it fetches each row of data.  The LongReadLen
attribute only relates to fetching/reading long values
it is not involved in inserting/updating them.

A value of 0 means don't automatically fetch any long
data (fetch should return undef for long fields when
LongReadLen is 0).

The default is typically 0 (zero) bytes but may vary
between drivers.  Applications fetching long fields
should set this value to slightly larger than the
longest long field value which will be fetched.

##</code><code>##

 $dbh->{LongReadLen} = 65536;
 my $sth = $dbh->prepare( 'select blah from bleh' );
 $sth->execute;
 ...