[CASSANDRA-17221] Add Math functions

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 5.0-alpha1, 5.0
• Component/s: CQL/Syntax
• Labels: AdventCalendar2021 lhf
• Change Category: Semantic
• Complexity: Low Hanging Fruit
• Platform: All

Source Control Link

https://github.com/apache/cassandra/commit/88dc64d2086c9a91f00ee024b8ef13cb2c193ee6

Test and Documentation Plan

The patch adds new tests

• Assignee: Simon Chess
• Reporter: Benjamin Lerer

Authors

Simon Chess

Reviewers

Benjamin Lerer, Ekaterina Dimitrova

• Created: 18/Dec/21 17:20
• Updated: 12/Sep/23 13:03
• Resolved: 22/Nov/22 17:28

Description

We should add native Maths functions for the most common operations:

• abs(x) returns the absolute value of the x
• exp(x) returns the value of e (the base of natural logarithms) raised to the power of x
• log(x) returns the natural logarithm (base e) of x
• log10(x) returns the base-10 logarithm of x
• round(x) returns the closest integer to x

Additional information for newcomers:

The new functions should be put in a new class MathFcts similar to TimeFcts.
The MathsFcts.all() method should be called in SystemKeyspace.functions
The unit tests for the functions should be put in a MathFctsTest similar to TimeFctsTest