course hero can a two-schema architecture be used instead (explain)? what needs to be changed?

What is the three schema architecture?

This framework is used to describe the structure of a specific database system. The three schema architecture is also used to separate the user applications and physical database. The three schema architecture contains three-levels. It breaks the database down into three different categories. It shows the DBMS architecture.

What is the conceptual level of a schema?

Conceptual Level 1 The conceptual schema describes the design of a database at the conceptual level. ... 2 The conceptual schema describes the structure of the whole database. 3 The conceptual level describes what data are to be stored in the database and also describes what relationship exists among those data. More items...

Why are schemas important to organizations?

Each schema is important to different groups in an organization. The graphic below illustrates this architecture and the groups most involved with each schema. The notion of user views was mentioned earlier. SQL is used to create (DDL) data definition language, which enables the creation of tables.

What is the difference between a view schema and subschema?

The subschema is used to describe the different view of the database. An external schema is also known as view schema. Each view schema describes the database part that a particular user group is interested and hides the remaining database from that user group. The view schema describes the end user interaction with database systems.

Why are databases characterized by a three-schema architecture?

Databases are characterized by a three-schema architecture because there are three different ways to look at them. Each schema is important to different groups in an organization. The graphic below illustrates this architecture and the groups most involved with each schema.

What is a logical schema?

This schema is developed with diagrams that define the content of database tables and describe how the tables are linked together for data access .#N#Database designers are responsible for creating the logical schema. Application developers and database administrators may find the logical schema useful for performing certain tasks.

What is the purpose of the three schema architecture?

The three schema architecture is also used to separate the user applications and physical database. The three schema architecture contains three-levels. It breaks the database down into three different categories. It shows the DBMS architecture.

What is internal schema?

The internal schema is also known as a physical schema. It uses the physical data model. It is used to define that how the data will be stored in a block. The physical level is used to describe complex low-level data structures in detail. 2.

What is conceptual level?

The conceptual level describes what data are to be stored in the database and also describes what relationship exists among those data.

What is the purpose of a subschema?

At the external level, a database contains several schemas that sometimes called as subschema. The subschema is used to describe the different view of the database. An external schema is also known as view schema. Each view schema describes the database part that a particular user group is interested and hides the remaining database from ...

Why is mapping not good?

Mapping is used to transform the request and response between various database levels of architecture. Mapping is not good for small DBMS because it takes more time. In External / Conceptual mapping, it is necessary to transform the request from external level to conceptual schema. In Conceptual / Internal mapping, ...