What are database architectures in SQL?

[Chillam]

Hello friends, I have heard there are different types of database architecture in SQL. But, I am not aware of any of them. I want to know what the database architecture in SQL is. Is it possible to get the information about database architecture in SQL. If anybody can help me in this query then it will be quite easy.

[Steyn]

In single-database architecture the DBMS supports one system wide database. All the information (Order Processing Data, Payroll Data) is stored using single database. All the database tables are owned by single database user. In this architecture various applications can easily refer one another. With proper permissions users can run queries that combine data from the various applications. The size of the database is very huge so not easy to manage. Performing operations like backups, recovering data needs full time administrator

[Ronchi]

In multi database architecture each database is assigned a unique name. The information is distributed across multiple databases. The main advantage of the multi database architecture over single database architecture is that it divides the data management tasks into smaller, more manageable pieces. Each person responsible for an application can now be the database administrator of his or her own database.

[Shreevats]

The main disadvantage of multi database architecture is that the databases are not connected to each other. Often the DBMS does not support queries across database boundaries, making it impossible to relate data from two applications. If a DBMS uses a multi database architecture and supports queries across databases, it must extend the SQL table and column naming conventions. A qualified table name must specify not only the owner of the table, but also which database contains the tables.