Apparently, it doesn't really close *all* connections; just those used by the current script.
If you are using persistent connections, every time a script does an odbc_pconnect() and all open connections are in use you'll get a new connection with the same credentials. You won't close them all with odbc_close_all().
(PHP 4, PHP 5)
odbc_close_all — Close all ODBC connections
odbc_close_all() will close down all connections to database server(s).
Această funcție nu are parametri.
Nu este întoarsă nici o valoare.
This function will fail if there are open transactions on a connection. This connection will remain open in this case.