Dodatkowe przykłady dopasowywane są do haseł w zautomatyzowany sposób - nie gwarantujemy ich poprawności.
The relational algebra is a collection of operators on relations.
The other basic operations in the relational algebra are not traditional set operators.
This requirement is met by the minimum cover set of the relational algebra.
At the least, they differ from techniques commonly used in relational algebra.
The set of operators are known together as the Relational Algebra.
This approach is also used in relational algebra.
Its computational expressiveness is equivalent to that of Relational algebra.
Relational algebra, in which a set of finitary relations that is closed under certain operators.
The relational algebra is fairly simple and powerful.
Practically any academic textbook on databases has a detailed treatment of the classic relational algebra.
The projection of a string is essentially the same as a projection in relational algebra.
The relational algebra is a procedural language.
We now look at the relational algebra and the relational calculus in more detail.
The From clause is technically required in relational algebra and in most scenarios to be useful.
The unary operation of projection in relational algebra.
In using the relational algebra.
This is similar to a projection in Relational algebra, except that in the general case, the result may contain duplicate rows.
The text also touched on set theory and relational algebra as ways of going beyond FOL.
Furthermore, computing various functions on a column, like the summing up its elements, is also not possible using the relational algebra introduced so far.
The relational algebra allows data duplication in the relations that are the elements of the algebra.
See also binary relation, triadic relation, relational algebra, theory of relations.
Data are operated upon by means of a relational calculus or relational algebra, these being equivalent in expressive power.
Note that the set of all attributes is a trivial superkey, because in relational algebra duplicate rows are not permitted.
Equijoin in relational algebra.
Query languages that are equivalent in expressive power to relational algebra were called relationally complete by Codd.