######### my code #########

use strict;
use warnings;
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
use DBD::Oracle;

# Create the CGI object
my $cgi = new CGI;

###############################################
# Connect to database

 my $db_server = "";
 my $host = $db_server;
 my $db = "";
 my $db_user = "";
 my $db_password = '';
 my $dbh = DBI->connect("dbi:Oracle:$host", "$db_user", "$db_password") or die "Couldn't connect to database: ".DBI->errstr;

my $sql;
my $sth;
my $table;
$table = "";
#####################################################

my $a_pk;
my $a_image;
my $max_lob;

$sql = "select max(length(a_image)) from  a_BLOB";
$sth = $dbh->prepare( $sql );
$sth->execute();
$sth->bind_columns(undef,\$max_lob);
   while($sth->fetch()) {
    #print "the greatest length image = $max_lob\n";
}
$sth->finish();

$dbh->{'LongReadLen'} = $max_lob;

##############

$sql = "select a_IMAGE from a_BLOB where a_pk = 123";
$sth = $dbh->prepare( $sql );
my $numrows = $sth->execute;
open OUTPUT, ">output.png";
binmode(OUTPUT);
$sth->bind_columns(undef,\$sp_image);
   while($sth->fetch()) {
print OUTPUT $sp_image;
close(OUTPUT)
}

$sth->finish;
$dbh->disconnect;
########################## code ends ##############