# --- untested ---
$dbh->LongReadLen = 100 * 1024; # 100 KB
$dbh->LongTruncOK =0;           # will fail if the column is too big

my $sth = $dbh->prepare(qq{select image from table where id=  ? });
my $image = undef;
$sth->execute(1);
my $record = $sth->fetchrow_hashref();
$image = $record->{"image"};
$sth->finish;

##</code><code>##

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