使用变量Clob在Out中运行函数时出错（PHP，Oracle，Laravel）

I have an application developed with the Laravel php framework. And I use the following package to work with my oracle database. https://github.com/yajra/laravel-oci8

I have the following function in oracle:

function my_func(uid in number, json in out nocopy clob) return number is

And in php I call it that

$result = '';

$pdo = DB::connection('oracle')->getPdo();

$stmt = $pdo->prepare("begin :result := my_func(:uid, :json); end;");
$stmt->bindParam(':result', $result, \PDO::PARAM_INT);
$stmt->bindParam(':uid', $uid, \PDO::PARAM_INT);
$stmt->bindParam(':json', $json, \PDO::PARAM_STR, 1000000);
$stmt->execute();

return response()->json(json_decode($json), ($result === 1) ? 200 : 
400);

When the output of 'json' is smaller than 32767 characters, then the code works. But when it is greater the following exception occurs:

Oci8Exception {#615
#message: """
Error Code : 6502

Error Message : ORA-06502: PL/SQL: erro numérico ou de valor

System details Oracle 11g

Ubuntu 18.04

PHP 7.2

Laravel 5.5

Laravel-OCI8 5.5

I was able to develop a solution. Not sure if it is the best, but it worked.

$result = $lob = '';

$pdo = DB::connection('oracle')->getPdo();

$stmt = $pdo->prepare("declare v_uid number(10) := :uid; v_data clob := :data; begin :result := my_func(v_uid, v_data); :lob := v_data; end;");

$stmt->bindParam(':result', $result, \PDO::PARAM_INT);
$stmt->bindParam(':uid', $uid, \PDO::PARAM_INT);
$stmt->bindParam(':data', $data, \PDO::PARAM_STR);
$stmt->bindParam(':lob', $lob, SQLT_CLOB);
$stmt->execute();

$json = $lob->read($lob->size());

return response()->json(json_decode($json), ($result === 1) ? 200 : 400);