Developing Map Databases: Problems and Solutions - Maps for the Future Children Education and Internet - page 145

available for special users with the help of a series of SQL commands and to a very
much limited extent for users without personal identification (such as queries from
any elte domain). Naturally, the whole arsenal of SQL can be applied in the process
of data loading and database building, because the data loading application supports
these processes.
There is no SQL interface in the vector subsystem. The expressive names of
libraries and files make the navigation easy in the file system. A table of metadata
might be put into service with the pure task of querying in the future, but it is
certainly not going to be a part of version 3.0.
12.4 Authentication, Security and Data Loading
The authentication of the database against hackers in the cyber space is a very
important issue. It is not worth building large databases if we cannot protect the
server from the attacks of hackers, because the frequency and complexity of the
attacks will surely lead to data loss.
The protection must be guaranteed at two levels. Namely, the server and
database must be protected. The protection of the server is the task of the adminis-
trator of the operating system, which includes the following tasks: virus protection,
setting up of the firewall, setting up of the Internet Information Service, and the
regular refreshing of the operating system of the server. The server is not accessible
from a local network. It has only one public directory, into which certain files
(e.g., tif, jpg, tab, shp) can be loaded from a few dedicated computers. In this case,
the data loading application imports the requested maps.
Although the protection of the server protects the database too, but the efficient
protection of the database needs additional settings. It must be decided in the
administration of the database management system that which users have the
right to access the database tables and to what extent. There are users who, without
personal identification, have the select right only. (These are requests from URLs
on the elte domain.) Others, who have personal authentication, have not only the
select right to access the database. The series of SQL commands is also available
for them, and they can download the selected maps on their client computer.
Only users with special rights are allowed to load and maintain the data. They
have the right to not only select, but also to update and delete information.
However, they do not have the right to delete large amount of data, to drop tables
or to perform any other operation that would corrupt the data. The administrator
only has full rights over the database.
The loading and maintenance of data is performed by a win32 application
running on a server, which is available for registered users only. This application
allows the editing of the existing map data, the changing of the attribute data, as
well as updating the data and the manipulation of the existing maps (Fig. 12.5 ). In
addition, the new maps are entered into the system by using this program. The
directory of the server that receives the uploaded data is only accessible with the