When will it stop. These amateur programmers that simply cut/paste code really affect those good programmers in the ecosystem trying to make a decent living. I was reviewing a developed (but incomplete) PHP/MySQL system using a common framework (which in itself is irrelevant for this post).

In one source file there were 12 repetitions of the following code:

   //permissions
    $this->security_model->setUserPermissions($id);
    if (!array_key_exists($id,$this->session->userdata['permissions']) OR
        !array_key_exists('id', $this->session->userdata['permissions'][$id]) OR
        !array_key_exists('scope', $this->session->userdata['permissions'][$id]['name'])){
      $this->session->set_flashdata('alert', 'You are not authorized to go there.');
      redirect($this->agent->referrer());
    }

It’s bad enough when code is repeated and not put in a simple re factored function. When it’s …

I got home today and sat down to read my home email list. Nothing new. But on a MySQL mailing list, there was an enquiry why performance was slowing in a given application. I didn’t even have to read the situation, nor the problem, it took less then the 200ms mentioned to identify the problem looking at the supplied schema.

In summary, the first table in the schema had a primary key of VARBINARY(255) and a engine type of Innodb. Hold on, wait, it’s a concatenated key of two VARBINARY(255) columns. And I should mention, that primary key was a foreign key in the next table. If this was a home website app with one user, ok well it’s still bad, but this application was having performance problems with reasonable volumes of transactions, it’s not a beginner application. (A recent reference If you don?t know your data, you don?t know your application). Where do people learn …