Database

Database is a storage for data and other database objects. Each SQL server serves only a single database.

Database registration

Each database is designated by its name and is registered under this name both on the server and client computers. Server gets the database name on startup and locates the appropriate database file by using the database registration entries. A client uses database registration entries to get the network address of the server working with the database, so the client can connect to the server.

Databases are registered in the system registry on Windows, and in the /etc/602sql configuration file on Linux.

Internal database architecture

Database can be internally divided into schemes. Each object (such as a database table) belongs to a particular scheme. More objects of the same name may exist in different schemes. The schemes usually correspond with the database applications being run on the server. The schemes mostly contain data tables, stored procedures or components of the user application interface.

Planning shared databases and network database servers

Data, that should be accessible over a network can be stored in a single central database or divided into more databases. Several things should be considered when deciding how many databases to use:

you can run more servers on a single computer and therefore you can make more database accessible from a single computer;
it's most effective that the server is running on the computer where the database file is being stored;
a database application is usually connected only to a single server at a time - the data to work with should be also only in a single database;
if a database application is being run and developed at the same time, it's recommended to have both applications in different databases;
if the data integrity, security and administration rests upon more users, it may be useful to split the data into separate databases;
server doesn't have to run on a dedicated computer, you can run a server offering network services on a client computer as well.

Apart from the network database sharing, users can create local databases for private data handling. These databases are run over local servers.

List of topics:

602SQL Server

SQL Server Operation