0
A database schema describes the overall logical structure and relationship of data within the database.
Such a schema will include all joins within the database and describe the relational sets.
It is best thought of as a written description in formal terms describing the entities/tables, their attributes and the relations between individual tables in terms of primary (local) keys, foreign keys.
A primary key is the attribute (or set of attributes) whose value(s) is unique within an individual entity/table to access all data in a single record.
A foreign key, is a key from another table/entity that is used to join an entity/table with another entity/table, so that all data records related to the primary key can be displayed.
What else can I help you with?
What kind of relationship describes when a record from one table is related to several records in another table?
The relationship that describes when a record from one table is related to several records in another table is called a "one-to-many" relationship. In this scenario, a single record in the first table can be associated with multiple records in the second table, while each record in the second table is linked to only one record in the first table. This type of relationship is commonly used in database design to represent hierarchical data structures.
What are predicates that define correct database states and relationship with in database?
schema
What best describes an active directory forest?
A collection of domains that share a common schema
What is global conceptual schema?
The enterprise view of the data is described by the global conceptual schema (GCS), which is global because it describes the logical structure of the data at all the sites.
What is a schema describes?
A schema describes the structure and organization of a database. It defines the tables, attributes, relationships, constraints, and data types that make up the database. It is like a blueprint that ensures data integrity and consistency.
What is Schema and instances?
In DBMS,Schema is the overall Design of the Database.Instance is the information stored in the Database at a particular moment.In programming,you declare a variable which corresponds to "Schema".But its values changes as and when required which corresponds to "Instance". Google about levels of Database Abstraction. Physical Schema describes database design at physical level while a logical schema describes the database design at the logical level.A database may also have several schemas at the view level, sometimes called subschemas, that describe different views of the database.
What is schema instance?
In DBMS,Schema is the overall Design of the Database.Instance is the information stored in the Database at a particular moment.In programming,you declare a variable which corresponds to "Schema".But its values changes as and when required which corresponds to "Instance". Google about levels of Database Abstraction. Physical Schema describes database design at physical level while a logical schema describes the database design at the logical level.A database may also have several schemas at the view level, sometimes called subschemas, that describe different views of the database.
What is xml schema?
XML Schema is an XML-based alternative to DTD.An XML schema describes the structure of an XML document.The XML Schema language is also referred to as XML Schema Definition (XSD).An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself.
What relationship describes when a record from one table is related to several records in another table.?
One-to-many relationship. This means that for every record in the first table, there can be multiple related records in the second table, but each related record in the second table corresponds to only one record in the first table.
What represents a correspondence between various data elements?
relationship
Discuss the basic differences between external schema conceptual schema and internal schema?
The internal schema describes how the data will be physically stored and accessed, using the facilities provided by a particular DBMS. For example, the data might be organized so that all the insurance policies belonging to a given customer were stored close together, allowing them all to be retrieved into the computer's memory in a single operation. The conceptual schema (sometimes called the logical schema) describes the stored data in terms of the data model of the DBMS. In a relational DBMS, the conceptual schema describes all relations that are stored in the database The external schemasspecify views that enable different users of the data to see it in different ways. As a simple example, some users of policy data might not require details of the commission paid. By providing them with a view that excludes the Commission Rate column, we would not only shield them from unwanted (and perhaps unauthorized) information, but also insulate them from changes that might be made to the format of that data.by:mohammed abu Lamdy
What is a document that describes database objects and their data types?
A data dictionary is a document that describes database objects such as tables, columns, and their corresponding data types. It provides information about the structure, relationships, and constraints of the database schema.
