• In database theory, relational algebra is a theory that uses algebraic structures for modeling data and defining queries on it with well founded semantics...
    42 KB (4,790 words) - 18:08, 12 November 2024
  • In relational algebra, a projection is a unary operation written as Π a 1 , . . . , a n ( R ) {\displaystyle \Pi _{a_{1},...,a_{n}}(R)} , where R {\displaystyle...
    7 KB (747 words) - 23:38, 17 October 2024
  • Thumbnail for Selection (relational algebra)
    In relational algebra, a selection (sometimes called a restriction in reference to E.F. Codd's 1970 paper and not, contrary to a popular belief, to avoid...
    9 KB (677 words) - 09:18, 23 February 2024
  • database. The relational calculus is similar to the relational algebra, which is also part of the relational model: While the relational calculus is meant...
    3 KB (359 words) - 11:59, 22 April 2024
  • In relational algebra, a rename is a unary operation written as ρ a / b ( R ) {\displaystyle \rho _{a/b}(R)} where: R is a relation a and b are attribute...
    2 KB (175 words) - 09:30, 11 July 2023
  • A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A database management system used...
    32 KB (3,840 words) - 13:01, 23 October 2024
  • (sigma algebra), a refinement of sigma algebras Join (algebraic geometry), a union of lines between two varieties In computing: Join (relational algebra),...
    1 KB (208 words) - 01:30, 3 October 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 (4,204 words) - 23:09, 18 October 2024
  • Thumbnail for Equivalence relation
    = { x ∈ X : x ∼ a } . {\displaystyle [a]=\{x\in X:x\sim a\}.} In relational algebra, if R ⊆ X × Y {\displaystyle R\subseteq X\times Y} and S ⊆ Y × Z {\displaystyle...
    31 KB (4,436 words) - 19:07, 29 October 2024
  • algebraic structures, such as groups, rings, etc. Elementary algebra, i.e. "high-school algebra" Abstract algebra Linear algebra Relational algebra Universal...
    3 KB (415 words) - 17:08, 30 November 2021
  • directed graphs, where objects reference each other. Relational is tuples in tables with relational algebra. Tuples are data fields grouped into a "row" with...
    17 KB (1,807 words) - 04:05, 18 September 2024
  • well as relational algebra) are equivalent in expressive power. Subsequently, query languages for the relational model were called relationally complete...
    15 KB (2,295 words) - 18:23, 10 December 2022
  • Look up relational in Wiktionary, the free dictionary. Relational may refer to: Relational capital, the value inherent in a company's relationships with...
    3 KB (414 words) - 06:06, 11 November 2020
  • data Relation (database), a component of a relational database Relational algebra Relational calculus Relational database, a digital database Relationships...
    2 KB (301 words) - 18:04, 26 February 2024
  • Universal algebra (sometimes called general algebra) is the field of mathematics that studies algebraic structures themselves, not examples ("models")...
    24 KB (2,953 words) - 06:54, 31 August 2024
  • theoretical properties that larger classes of queries (e.g., the relational algebra queries) do not share. The conjunctive queries are the fragment of...
    15 KB (1,922 words) - 01:57, 13 December 2023
  • variables. Its computational expressiveness is equivalent to that of relational algebra. Let (A, B, C) mean (Rank, Name, ID) in the Enterprise relation and...
    4 KB (624 words) - 13:44, 22 April 2024
  • Database normalization is the process of structuring a relational database accordance with a series of so-called normal forms in order to reduce data redundancy...
    36 KB (2,880 words) - 14:22, 30 October 2024
  • 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) - 23:38, 17 October 2024
  • denoted ρ π {\displaystyle \rho ^{\pi }} The rename operation in relational algebra In economics to represent the discount rate of future pence cash flows...
    6 KB (896 words) - 01:19, 27 October 2024
  • 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
  • Thumbnail for Join (SQL)
    into a new table. The operation corresponds to a join operation in relational algebra. Informally, a join stitches two tables and puts on the same row records...
    42 KB (4,777 words) - 15:02, 30 July 2024
  • relational algebra defined by Codd in "Relational Completeness of Data Base Sublanguages"), which IBM developed for its first commercial relational database...
    1 KB (149 words) - 00:39, 22 April 2024
  • Thumbnail for Entity–relationship model
    semantics and implementation are based on reshaped relational algebra (RRA), a relational algebra that is adapted to the entity–relationship model and...
    34 KB (4,346 words) - 23:19, 10 November 2024
  • Octonion algebra Pre-Lie algebra Poisson algebra Process algebra Quadratic algebra Quaternion algebra Rees algebra Relation algebra Relational algebra Rota–Baxter...
    2 KB (226 words) - 16:33, 17 January 2024
  • Thumbnail for Set theory
    various applications in computer science (such as in the theory of relational algebra), philosophy, formal semantics, and evolutionary dynamics. Its foundational...
    42 KB (5,066 words) - 19:14, 5 November 2024
  • guide to algebra Quaternion – Noncommutative extension of the complex numbers Rational function – Ratio of polynomial functions Relational algebra – Theory...
    139 KB (14,097 words) - 09:01, 16 November 2024
  • NoSQL (originally referring to "non-SQL" or "non-relational") is an approach to database design that focuses on providing a mechanism for storage and retrieval...
    29 KB (2,417 words) - 17:13, 25 October 2024
  • operator in mathematics a plane the unary projection operation in relational algebra the Pi function, i.e. the Gamma function when offset to coincide with...
    37 KB (3,441 words) - 16:38, 16 October 2024
  • Haskell records. Relational databases may formally identify their rows (records) as tuples. Tuples also occur in relational algebra; when programming...
    16 KB (2,200 words) - 10:13, 13 November 2024