confluentinc/ksql

avg should return null when no row is aggregated

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#9,752 opened on Jan 4, 2023

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 (1 comment) (0 reactions) (0 assignees)Java (1,048 forks)batch import
enhancementgood first issue

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Description

Is your feature request related to a problem? Please describe. avg returns 0.0 instead of NULL when no row is aggregated. However, IMHO, NULL is preferable because 0.0 means nothing. In addition, other projects like apache spark return null in this case. What do you think?

Describe the solution you'd like avg should return null when no row is aggregated.

Describe alternatives you've considered

Additional context

Contributor guide

Research direction
Investigate the current implementation of the avg aggregate function to understand why it returns 0.0 instead of NULL when no rows are aggregated. Identify the place where the default value is set and modify it to return null.
Tech stack
java
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaGit
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70