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Rule 10: Integrity independence: Integrity constraints specific to a particular relational data base must be definable in the relational data sublanguage and storable in the catalog, not in the application programs. Rule 11: Distribution independence: The end-user must not be able to see that the data is distributed over various locations.
Every request received by a non-failing node in the system must result in a response. This is the definition of availability in CAP theorem as defined by Gilbert and Lynch. [1] Note that availability as defined in CAP theorem is different from high availability in software architecture. [5] Partition tolerance
This does not guarantee correctness of the transaction in all ways the application programmer might have wanted (that is the responsibility of application-level code) but merely that any programming errors cannot result in the violation of any defined database constraints. [1] In a distributed system, referencing CAP theorem, consistency can ...
The conceptual schema describes all the data items and relationships between them, together with integrity constraints (later). There is only one conceptual schema per database. The internal schema at the lowest level contains definitions of the stored records, the methods of representation, the data fields, and indexes. There is only one ...
The model contains a number of basic constructs that represent both data items and processes that operate on those data items. The key data type in the Clark–Wilson model is a Constrained Data Item (CDI). An Integrity Verification Procedure (IVP) ensures that all CDIs in the system are valid at a certain state.
Atomicity, consistency, isolation (sometimes integrity), durability is a transaction metric. When dealing with safety-critical systems, the acronym reliability, availability, maintainability and safety is frequently used. [citation needed] Dependability is an aggregate of availability, reliability, safety, integrity and maintainability.
A distributed SQL database is a single relational database which replicates data across multiple servers. Distributed SQL databases are strongly consistent and most support consistency across racks, data centers, and wide area networks including cloud availability zones and cloud geographic zones. Distributed SQL databases typically use the ...
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 ).