confluentinc/ksql

Array size function / Rank

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#2,579 opened on Mar 19, 2019

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 (3 comments) (0 reactions) (0 assignees)Java (1,048 forks)batch import
help wanteduser-defined-functions

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Description

Hi, I've noticed that there is no RANK() or DENSE_RANK() function in KSQL. I tried to work around this by calling TOPKDISTINCT(col, static_int) and then returning the size of the array given by TOPKDISTINCT(), all within my relevant group by. Is there any workaround for this? I am not well versed in Java/Scala, so I could try writing this as a UDF, but I would prefer is there was a native solution for this. Cheers!

Contributor guide

Research direction
Explore existing KSQL windowing and aggregation functions to simulate ranking, or consider implementing a custom UDAF/UDF for RANK/DENSE RANK.
Tech stack
javasql
Domain
apibackend
Issue type
Feature
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
KSQLSQL
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60