The php files generated for codepages caches have one php opcode for every element of the codepage arrays, eg:

$var = array();
$var[0] = 0;
...
$var['999'] = '999';

A better solution is to have php code that generates a single php opcode for the same operation, ie:

$var = array(
0 => 0,
...
'999' => '999'
);

The attached version of ezcodepage.php does this (modified an ezp 4 svn baseline).