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Quorum (distributed computing) A quorum is the minimum number of votes that a distributed transaction has to obtain in order to be allowed to perform an operation in a distributed system. A quorum -based technique is implemented to enforce consistent operation in a distributed system.
In computer systems security, role-based access control (RBAC) [1][2] or role-based security[3] is an approach to restricting system access to authorized users, and to implementing mandatory access control (MAC) or discretionary access control (DAC). Role-based access control is a policy-neutral access control mechanism defined around roles and ...
The PACELC theorem, introduced in 2010, [9] builds on CAP by stating that even in the absence of partitioning, there is another trade-off between latency and consistency. PACELC means, if partition (P) happens, the trade-off is between availability (A) and consistency (C); Else (E), the trade-off is between latency (L) and consistency (C).
A data stream management system (DSMS) is a computer software system to manage continuous data streams. It is similar to a database management system (DBMS), which is, however, designed for static data in conventional databases. A DBMS also offers a flexible query processing so that the information needed can be expressed using queries.
Mandatory access control. In computer security, mandatory access control (MAC) refers to a type of access control by which a secured environment (e.g., an operating system or a database) constrains the ability of a subject or initiator to access or modify on an object or target. [1] In the case of operating systems, the subject is a process or ...
Rule 11: Distribution independence: The end-user must not be able to see that the data is distributed over various locations. Users should always get the impression that the data is located at one site only. Rule 12: The nonsubversion rule: If a relational system has a low-level (single-record-at-a-time) language, that low level cannot be used ...
The general area of concurrency control provides rules, methods, design methodologies, and theories to maintain the consistency of components operating concurrently while interacting, and thus the consistency and correctness of the whole system. Introducing concurrency control into a system means applying operation constraints which typically ...
A relational database (RDB[ 1 ]) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. [ 2 ] A database management system used to maintain relational databases is a relational database management system (RDBMS). Many relational database systems are equipped with the option of using SQL (Structured Query ...