apache/pinot

What's the root cause to wiki's recommendation: "Pause consumption when add a new column"?

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#12,652 建立於 2024年3月14日

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 (4 留言) (0 反應) (0 負責人)Java (4,937 star) (1,234 fork)batch import
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描述

In the ingestion transformation wiki page, it mentioned that

If a new column is added to table or schema configuration during ingestion, incorrect data may appear in the consuming segment.

To ensure accurate values are reloaded, do the following: Pause consumption (and wait for pause status success)

Is it only limited to table which has ingestion transform config? If not, it seems a breaking change since we need to pause consumption for every schema update.

Another question: In which scenario the data will incorrectly appears?

貢獻者指南

技術棧
javasql
領域
databasedocumentation
議題類型
documentation
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
1-3 hours
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
active
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
Apache Pinot basicsIngestion transformations
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
40
研究方向
Start by examining the ingestion transformation code in Apache Pinot, particularly the handling of schema changes during segment consumption. Look at the IngestionTransformations class and related consumer logic to understand the root cause of the recommendation to pause consumption. Check for any race conditions or assumptions about schema stability that could lead to incorrect data.