Sort

Tuple Level

Syntax:

Written Syntax: RelationA τ RelationB Arcade Syntax: Currently Not Supported

Operation Definition

This is a unary operator that rearranges the list order of the tuples. Note that this operation does not change the underlying representation and is really for visualization purposes only. This operation requires:

  1. 1) L, a subset <a1, a2, a3,…, an>of the attributes of the relation to sort the tuples by. The tuples are first sorted in ascending order according to their a1 component by using the concept of greater than (>) and lesser than operators (<). Ties within a1 are broken using a2 component values and so forth for further ties.

Usefulness:

Used typically for display and readability purposes. Since relations are sets, ordering is usually not considered.

Example:

Bam (Orginal)
D E
21 30
20 30
53 62
11 10

Sort[E, D](Bar)
D E
11 10
20 30
21 30
53 62