StarRocks/starrocks

Support using JSON as GROUP BY

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#62,502 opened on 2025年8月29日

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 (4 comments) (0 reactions) (1 assignee)Java (5,717 stars) (1,246 forks)batch import
good first issuetype/enhancement

説明

Enhancement

MySQL root@127.1:d1> select event_date from tjson group by event_date;
(1064, 'Getting analyzing error. Detail message: Type (nested) percentile/hll/bitmap/json not support group-by.')

JSON is currently not supported in the GROUP BY clause, but enabling this functionality could be beneficial for certain scenarios.

To implement GROUP BY support for JSON, a stable hash function and comparison function are required. This can be achieved using asymmetric hash mixing techniques, such as XOR, which is already implemented in JsonValue::hash.

コントリビューターガイド

技術スタック
javasql
領域
databaseperformance
Issue 種別
feature
難度新しい貢献者にとっての実装難度です。1 は非常に小さな変更、5 は専門的な作業です。
4
推定時間経験ある貢献者が調査、実装、テスト、pull request 準備にかけるおおよその時間範囲です。
over 1 week
活動状況Issue が今どれだけ取り組みやすいかを示します。新しい、活発、古い、ブロック中、またはメンテナー入力待ちなどです。
blocked
明確さ期待される変更、受け入れ条件、次の手順がどれだけ明確かを示します。
clear
前提条件
StarRocks internalsJSON data typesHashing techniques
初心者向け度初回貢献者にどれだけ取り組みやすいかを 1-100 で推定したスコアです。
30
調査方針
Investigate the current implementation of JsonValue::hash in the StarRocks codebase (likely in the C++ backend). Understand how asymmetric hash mixing is implemented and extend the GROUP BY operator to support JSON type by using that hash function. Also need a comparison function. Check if any existing similar implementations for other types can serve as a template. Refer to the issue comments for any additional maintainer guidance.
Support using JSON as GROUP BY · StarRocks/starrocks#62502 | Good First Issue