In relational algebra, a projection is a unary operation written as Πa1,...,an(R){\displaystyle \Pi _{a_{1},...,a_{n}}(R)}, where R{\displaystyle R} is... 7 KB (719 words) - 16:11, 27 August 2023 |
In database theory, relational algebra is a theory that uses algebraic structures for modeling data, and defining queries on it with a well founded semantics... 50 KB (6,121 words) - 13:39, 19 February 2024 |
projection of a vector onto a straight line Projection (relational algebra), a type of unary operation in relational algebra Projective geometry, the study of geometric... 4 KB (500 words) - 19:31, 15 January 2024 |
Idempotent linear transformation from a vector space to itself Projection (relational algebra) – Operation that restricts a relation to a specified set of... 2 KB (304 words) - 15:36, 16 May 2023 |
evaluation map is a projection map from the Cartesian product.[citation needed] For relational databases and query languages, the projection is a unary operation... 13 KB (1,578 words) - 19:02, 18 March 2023 |
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A database management... 31 KB (3,782 words) - 03:55, 6 March 2024 |
The relational model (RM) is an approach to managing data using a structure and language consistent with first-order predicate logic, first described in... 30 KB (4,209 words) - 22:28, 25 March 2024 |
Imieliński–Lipski algebras are defined to satisfy precise conditions for semantically meaningful extension of the usual relational operators, such as projection, selection... 9 KB (947 words) - 08:16, 19 January 2024 |
In mathematics and abstract algebra, a relation algebra is a residuated Boolean algebra expanded with an involution called converse, a unary operation... 25 KB (2,541 words) - 06:17, 16 February 2024 |
Database normalization (redirect from Relational Database Normalization) Database normalization is the process of structuring a relational database in accordance with a series of so-called normal forms in order to reduce data... 36 KB (1,223 words) - 10:48, 23 February 2024 |
Relation of degree zero (category Relational algebra) 0-tuple.:56 The zero-degree relations represent true and false in relational algebra.:57 Under the closed-world assumption, an n-ary relation is interpreted... 3 KB (379 words) - 16:33, 8 April 2023 |
the relational algebra projection operation. AS optionally provides an alias for each column or expression in the SELECT list. This is the relational algebra... 33 KB (3,102 words) - 19:30, 20 March 2024 |
is a normal form used in relational database normalization which extends the relational algebra and generalizes relational operators (such as join) to... 10 KB (875 words) - 09:49, 28 March 2024 |
String operations (redirect from String projection) The projection of a string is essentially the same as a projection in relational algebra. String projection may be promoted to the projection of a language... 15 KB (2,273 words) - 00:51, 11 November 2023 |
a pi bond. The natural projection on the tangent bundle on a manifold. The unary operation of projection in relational algebra. Policy in reinforcement... 9 KB (784 words) - 13:33, 31 January 2024 |
of information algebras: Relational algebra: The reduct of a relational algebra with natural join as combination and the usual projection is a labeled information... 19 KB (2,244 words) - 02:30, 24 March 2024 |
Predicate (mathematical logic) Projection (set theory) Reflexive relation Relation algebra Relational algebra Relational model Relations (philosophy) Codd... 18 KB (1,906 words) - 02:48, 4 February 2024 |
the product operator in mathematics a plane the unary projection operation in relational algebra osmotic pressure π{\displaystyle \pi } represents: Archimedes'... 37 KB (3,386 words) - 02:12, 24 March 2024 |
Lift (mathematics) (section Algebraic logic) topology to calculus of relations in their book Relational Topology. They aim "to lift concepts to a relational level making them point free as well as quantifier... 5 KB (708 words) - 21:40, 21 September 2023 |
Haskell records. Relational databases may formally identify their rows (records) as tuples. Tuples also occur in relational algebra; when programming... 16 KB (2,043 words) - 21:03, 17 March 2024 |
Homomorphism (section Relational structures) In algebra, a homomorphism is a structure-preserving map between two algebraic structures of the same type (such as two groups, two rings, or two vector... 33 KB (4,117 words) - 23:50, 23 March 2024 |
Kripke semantics (redirect from Relational semantics) Kripke semantics (also known as relational semantics or frame semantics, and often confused with possible world semantics) is a formal semantics for non-classical... 34 KB (4,718 words) - 13:41, 28 February 2024 |
Signatures, TensorFaces TensorTexures and Multilinear Projection. Multilinear algebra, the algebra of higher-order tensors, is a suitable and transparent... 28 KB (3,570 words) - 03:57, 23 March 2024 |
systems. If there are relational data streams and the logical query plan is based on relational operators from the Relational algebra, a query optimizer... 13 KB (1,563 words) - 21:49, 15 January 2024 |
Three-valued logic (section Modular algebras) were then re-formulated by Grigore Constantin Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Around 1910, Charles... 25 KB (2,378 words) - 11:50, 5 March 2024 |
Composition of relations (category Algebraic logic) relations for n≥2,{\displaystyle n\geq 2,} is the join operation of relational algebra. The usual composition of two binary relations as defined here can... 17 KB (2,695 words) - 15:25, 11 October 2023 |
Put, Update, or Delete). While a typical relational system would convert the SQL query to relational algebra and run optimization algorithms, DynamoDB... 22 KB (2,475 words) - 20:57, 24 February 2024 |
Tensor product of graphs (redirect from Relational product) direct product, Kronecker product, categorical product, cardinal product, relational product, weak direct product, or conjunction. As an operation on binary... 8 KB (860 words) - 19:51, 10 September 2022 |