apache / apache/gluten

[BUG][CH] Corner case of unbase64

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#7,092 3 comments 0 reactions 0 assignees View on GitHub
bug triage
Dominant language
Scala
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Description

### Backend

CH (ClickHouse)

### Bug description

vanila spark:
`select unbase64('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA¬AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAyAAAAAAAEAAAAAAAAAAggAAAAAAAAAAQAsCQAAgMAAAJECQBUUEQBUAEFAEBMEAEEYRwQFAEFAEAARAACCAEQFEAVRwCAgAAqIAgAAAAALgAQIA7AIAAAABcBNCAQQYjAMAAACAgBptQxGSDAxcACBJBBQQhC5GnCBOVAVJAeQ==')
. . . . . . . . . . . . . . . > ;`
image

Gluten, got the same exception with Clickhouse,
`bigo :) select base64Decode('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA¬AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAyAAAAAAAEAAAAAAAAAAggAAAAAAAAAAQAsCQAAgMAAAJECQBUUEQBUAEFAEBMEAEEYRwQFAEFAEAARAACCAEQFEAVRwCAgAAqIAgAAAAALgAQIA7AIAAAABcBNCAQQYjAMAAACAgBptQxGSDAxcACBJBBQQhC5GnCBOVAVJAeQ==') as b`
image

Contributor guide

Open the contributing guide

Research direction

Start by running the provided unbase64 and base64Decode SQL reproductions and compare Gluten's behavior with vanilla Spark and ClickHouse. Trace the handling of the non-ASCII character in the input; done means the corner case has a defined, consistent result without the reported exception.

Written by the indexing model from the issue text.

Assessment

Tech stack
clickhouse, sql
Domain
backend, databases
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

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