PHP script slow on server, but fast in local - php

Question

First I want to say that my english is very poor, but I'm going to try.
I've tried to run a PHP script on my PC with wamp server and it works ok, but when I upload, for some reason, it spends so much time to complete the execution on the host, and almost always ends with a Service Temporarily Unavailable error (the host close the connection).
I've used some die() to see where is the problem and I found it's a for loop where I'm making a big string (I'm only concatenating to make a big INSERT for executing it after the loop). And this loop works in local... I can't understand why is not working on the host.
//insertar valores en bbdd
$sql = "Insert into valor values ";
$primer = 1;
$tiempo_inicio = microtime(true);
for($i = 0 ; $i <= count($array2) - 1 ; $i++)
{
//insertar glucosa
if(!$array2[$i][1] == "")
{
if (!$primer) $sql .= ", ";
else $primer = 0;
$sql .= "('" . $this->paciente . "', '" . $array2[$i][0] . "', 'Glucosa', " . $array2[$i][1] . ")";
$this->Comprobar_Aumentar_Avisos($array2[$i][0], $array2[$i][1]);
}
//insertar raciones
if(!$array2[$i][2] == "")
{
if (!$primer) $sql .= ", ";
else $primer = 0;
$sql .= "('" . $this->paciente . "', '" . $array2[$i][0] . "', 'Raciones', " . $array2[$i][2] . ")";
}
//insertar insulina
if(!$array2[$i][3] == "")
{
if (!$primer) $sql .= ", ";
else $primer = 0;
$sql .= "('" . $this->paciente . "', '" . $array2[$i][0] . "', 'Insulina', " . $array2[$i][3] . ")";
}
}
$tiempo_total = microtime(true) - $tiempo_inicio;
die($tiempo_total);
if ($sql != "Insert into valor values ") {
$AccessBD = new TAccessBD;
$AccessBD->usuario = $this->paciente;
$AccessBD->Inicialitzar_BD();
$AccessBD->query = $sql;
$res = $AccessBD->Ejecutar_SQL();
$AccessBD->Finalitzar_BD();
unset($AccessBD);
}

Answer 1

The problem was that in the loop I was accessing too many times the database in this function: $this->Comprobar_Aumentar_Avisos($array2[$i][0], $array2[$i][1]);
When accessing in local I have no problem, because of local database, but on the server, with the database in other external host too, it was very slow.
So I solved it reducing the number of accesses to database to the minimum I can and now it's working fine.
Thank you very much for the help!