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In database systems, atomicity (/ ˌ æ t ə ˈ m ɪ s ə t i /; from Ancient Greek: ἄτομος, romanized: átomos, lit. 'undividable') is one of the ACID (Atomicity, Consistency, Isolation, Durability) transaction properties. An atomic transaction is an indivisible and irreducible series of database operations such that either all occur ...
An ISBN would seem not to be atomic, as it includes language and publisher identifier. Date suggests that "the notion of atomicity has no absolute meaning": [9] [10] a value may be considered atomic for some purposes, but may be considered an assemblage of more basic elements for other purposes. If this position is accepted, 1NF cannot be ...
The following examples further illustrate the ACID properties. In these examples, the database table has two columns, A and B. An integrity constraint requires that the value in A and the value in B must sum to 100. The following SQL code creates a table as described above:
An atomic value may refer to: Atomic number , the number of protons in the nucleus of an atom A piece of data in a database table that cannot be broken down any further (see first normal form )
In computing, the attribute domain is the set of values allowed in an attribute. [1] For example: Rooms in hotel (1–300) Age (1–99) Married (yes or no) Nationality (Nepalese, Indian, American, or British) Colors (Red, Yellow, Green) For the relational model it is a requirement that each part of a tuple be atomic. [2]
An attribute value is the entry in a specific column and row. A database relvar (relation variable) is commonly known as a base table. The heading of its assigned value at any time is as specified in the table declaration and its body is that most recently assigned to it by an update operator (typically, INSERT, UPDATE, or DELETE). The heading ...
A relational database schema is defined as a tuple S = (D, R, h) where D is the domain of atomic values (see relational model for more on the notions of domain and atomic value), R is a finite set of relation names, and h : R → 2 C. a function that associates a header with each relation name in R. (Note that this is a simplification from the ...
In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has: An identification such as a data element name; A clear data element definition; One or more representation terms; Optional enumerated values Code (metadata)