Visual representation of database system relationships
MediaWiki 1.28.0 database schema. Many FOSS software tools allow modelling of DB layout/schemes like this. Visual representation often may also be exported as a production-ready source code made in DB-compatible languages like SQL.
The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS). The term "schema" refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases). The formal definition of a database schema is a set of formulas (sentences) called integrity constraints imposed on a database.[citation needed] These integrity constraints ensure compatibility between parts of the schema. All constraints are expressible in the same language. A database can be considered a structure in realization of the database language.[1] The states of a created conceptual schema are transformed into an explicit mapping, the database schema. This describes how real-world entities are modeled in the database.
"A database schema specifies, based on the database administrator's knowledge of possible applications, the facts that can enter the database, or those of interest to the possible end-users."[2] The notion of a database schema plays the same role as the notion of theory in predicate calculus. A model of this "theory" closely corresponds to a database, which can be seen at any instant of time as a mathematical object. Thus a schema can contain formulas representing integrity constraints specifically for an application and the constraints specifically for a type of database, all expressed in the same database language.[1] In a relational database, the schema defines the tables, fields, relationships, views, indexes, packages, procedures, functions, queues, triggers, types, sequences, materialized views, synonyms, database links, directories, XML schemas, and other elements.
A database generally stores its schema in a data dictionary. Although a schema is defined in text database language, the term is often used to refer to a graphical depiction of the database structure. In other words, schema is the structure of the database that defines the objects in the database.
In an Oracle Database system, the term "schema" has a slightly different connotation.
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The databaseschema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS)...
relational databaseschemas. A schema migration is performed on a database whenever it is necessary to update or revert that database'sschema to some newer...
(logic) Axiom schema, in formal logic Image schema, a recurring pattern of spatial sensory experience Databaseschema XML schema Body schema, a neural representation...
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been used in books and tutorials as examples of databaseschema and organizing content. The ISFDB database and code are available under Creative Commons...
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In databases, relational schema may refer to a databaseschema, in the relational paradigm a (single) relation schemaDatabaseschema. ... The term "schema"...
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will be influenced by the RDBMS that a database administrator (or an organization) chooses to use. Physical schema is a term used in data management to...
database-independent library for tracking, managing and applying databaseschema changes. It was started in 2006 to allow easier tracking of database...
the database performance, among others. SQL Server Management Studio can also be used to create a new database, alter any existing databaseschema by adding...
engineering approximation to the relational model. A table in a SQL databaseschema corresponds to a predicate variable; the contents of a table to a relation;...
A conceptual schema or conceptual data model is a high-level description of informational needs underlying the design of a database.[citation needed] It...
logical data model or logical schema is a data model of a specific problem domain expressed independently of a particular database management product or storage...
computer programming language for defining data structures, especially databaseschemas. Common examples of DDL statements include CREATE, ALTER, and DROP...
manager with support for database and schema permissions No - no user manager, or read-only user manager Legend: Visual schema/E-R design: the ability...
terms schema matching and mapping are often used interchangeably for a database process. For this article, we differentiate the two as follows: schema matching...
for network management, including an application layer protocol, a databaseschema, and a set of data objects. In typical uses of SNMP, one or more administrative...
within one data structure. Since this non-relational database design does not require a schema, it offers rapid scalability to manage large and typically...
In computing, the star schema or star model is the simplest style of data mart schema and is the approach most widely used to develop data warehouses and...
is a database model conceived as a flexible way of representing objects and their relationships. Its distinguishing feature is that the schema, viewed...
Object model Document model Entity–attribute–value model Star schema An object–relational database combines the two related structures. Physical data models...
System (MOLGENIS): alternatives in developing local experimental genomics databases". Bioinformatics. 20 (13): 2075–83. doi:10.1093/bioinformatics/bth206...
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