• In database theory, relational algebra is a theory that uses algebraic structures for modeling data and defining queries on it with well founded semantics...
    51 KB (6,354 words) - 10:15, 28 April 2025
  • 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) - 07:47, 26 March 2025
  • 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
  • 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...
    8 KB (677 words) - 20:58, 25 January 2025
  • 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) - 20:40, 5 December 2024
  • A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A Relational Database Management System...
    32 KB (3,869 words) - 06:09, 17 April 2025
  • 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 (4,196 words) - 15:00, 15 March 2025
  • 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 (1,798 words) - 04:49, 30 April 2025
  • 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 (4,473 words) - 11:36, 3 May 2025
  • 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...
    37 KB (2,918 words) - 07:42, 23 April 2025
  • related to query languages for relational databases, such as SQL. The following table maps between Datalog, relational algebra, and SQL concepts: More formally...
    59 KB (4,901 words) - 10:26, 17 March 2025
  • purpose of 1NF is to make the data model more flexible, to simplify the relational algebra and query language, and to enable further normalization levels which...
    19 KB (2,539 words) - 07:05, 9 May 2025
  • 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 (3,100 words) - 20:59, 25 January 2025
  • 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...
    54 KB (6,575 words) - 12:01, 1 May 2025
  • calculi (as well as relational algebra) are equivalent in expressive power.[citation needed] Subsequently, query languages for the relational model were called...
    15 KB (2,303 words) - 03:50, 13 April 2025
  • 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
  • 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) - 02:45, 12 January 2025
  • cover set of the relational algebra. The relational algebra allows data duplication in the relations that are the elements of the algebra. One of the efficiency...
    2 KB (244 words) - 01:31, 17 April 2025
  • 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) - 14:20, 21 November 2024
  • Universal algebra (sometimes called general algebra) is the field of mathematics that studies algebraic structures themselves, not examples ("models")...
    25 KB (3,043 words) - 08:54, 11 February 2025
  • (sigma algebra), a refinement of sigma algebras Join (algebraic geometry), a union of lines between two varieties In computing: Join (relational algebra),...
    2 KB (225 words) - 06:12, 2 May 2025
  • 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
  • be different on the surface: relational databases, multiple systems of formal logic or numerical problems of linear algebra. It allows the development of...
    19 KB (2,296 words) - 12:44, 23 January 2025
  • 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) - 03:42, 30 March 2025
  • without accessing the stored hierarchy relation". The standard relational algebra and relational calculus, and the SQL operations based on them, are unable...
    12 KB (1,527 words) - 12:00, 27 July 2024
  • "non-relational") refers to a type of database design that stores and retrieves data differently from the traditional table-based structure of relational databases...
    30 KB (2,437 words) - 06:52, 9 May 2025
  • Haskell records. Relational databases may formally identify their rows (records) as tuples. Tuples also occur in relational algebra; when programming...
    16 KB (2,224 words) - 06:56, 3 May 2025
  • 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
  • in the development of relational databases that recursive queries cannot be expressed in either relational algebra or relational calculus, and that this...
    85 KB (10,764 words) - 13:39, 8 May 2025
  • rename a file in various operating systems Rename (relational algebra), unary operation in relational algebra Company renaming, rename of a product Name change...
    652 bytes (92 words) - 08:27, 14 October 2023