Set and vertical combinations
What is the Relational Algebra operation that, when applied to relations, R and S, produces elements in R and S or both (duplications are removed)?
Union ( \cup )
What is the RA operation that when applies to two relations R and S that combines (horizontally) every tuple in R with every tuple in S.
Cartesian product (RxS)
What is the operation that remove duplicated tuples in a relation (R). (i.e., keep only one unique copy of every tuple)?
Duplication Elimination ( \delta(R) )
What is the Relational Algebra operation that, when applied to two relations, R and S, produces only tuples that appear in both R and S?
Intersection ( \cap )
What is the RA operator that when applies to two relations R and S will combine (horizontally) tuples from R with tuples from S automatically based on the attributes with the same name and same values and one copy of the duplicated attributes will be dropped?
Natural Join ( R\bowtie S )
What is the RA operation that when applies to relation R will return tuples from R ordered by a list of attributes (can be ascending or descending order)?
Ordering/Sorting ( \tau_{A_1, A_2, ...}(R) )
What is the Relational Algebra operation that, when applied to two relations, R and S (in order), produces the tuples in R but not in S?
Set difference ( R - S )
What is the RA operator that when applies to two relations R and S will combine (horizontally) tuples from R with tuples from S based on a predicate P?
Theta-join ( R \bowtie_PS )
What is the category of the operations that summarize or aggregate values in an attribute of a relation?
Aggregation Operations (e.g., SUM, MIN, MAX, AVG, COUNT).
What is the Relational Algebra operation that, when applied to a relation R, creates a new relation with some columns from R (takes all tuples but with some specified columns only)?
Projection ( \pi_{A_1, A_2, ...}(R) )
What is the RA operator that when applies to two relations R and S will combine (horizontally) tuples from R with tuples from S based on a predicate P, and all tuples in R that do not join with tuples in S still remains in the output (will be combined with nulls)?
Left Outer Join (R ⟕P S)
What is the operation that partitions tuples in a relation R into groups based on the values of a list of attributes (L)?
Grouping Operation ( \gamma_L(R) )
What is the Relational Algebra operation that, when applied to a relation R, returns a new relation with some tuples that satisfy a predicate (p) only (filter tuples and takes all the columns)?
Selection ( \sigma_{p}(R) )
What is the RA operator that when applies to two relations R and S will combine (horizontally) tuples from R with tuples from S based on a predicate P, and all tuples in R that do not join with tuples in S still and vice versa remain in the output (will be combined with nulls on other side)?
Full Outer Join (R⟗PS)
Given a relation Product(pId, catId, name, quantity). What is the RA expression to list each of the catId and total number of products in that category?
\gamma_{catID, SUM(quantity)}(R)