can database_tables.php be overridden?

[Jeff G]

I am using one database for several sites. Each site has its' own prefix for all tables.

I want to share the customer table (and probably some others).

Using info I found in a post, I changed

define('TABLE_CUSTOMERS',  DB_PREFIX .  'customers'); 

to

define('TABLE_CUSTOMERS', 'zen_customers'); 

This all seems to work fine, but I know it is highly recommended to not change files without using the override system.