shyjsarah opened a new issue, #583:
URL: https://github.com/apache/paimon-rust/issues/583

   ### Motivation
   
   Java Paimon supports 
`fields.<sequence-field>.sequence-group=<protected-fields>` for 
`merge-engine=partial-update` tables, but Paimon Rust currently only supports 
basic partial-update mode and rejects every `fields.*.sequence-group` option at 
table-open time.
   
   This prevents Paimon Rust / DataFusion from reading existing 
Java/Flink-created tables that use independent field-group sequencing. Falling 
back to the current basic latest-non-null merge would be incorrect because an 
older version from one update stream could overwrite fields protected by 
another sequence group.
   
   I searched the existing issues and did not find an issue covering 
partial-update sequence-group support.
   
   ### Proposed scope
   
   Add read-side sequence-group support for primary-key tables:
   
   - parse single and composite sequence fields and their protected fields;
   - validate referenced fields, duplicate protection, and primary-key 
conflicts;
   - widen projected reads with the sequence fields required by projected 
protected fields;
   - compare sequence tuples with Java-compatible null/ordering semantics;
   - update multiple independent groups without cross-group overwrites;
   - skip a group when all of its sequence fields are null;
   - add Java-written / Rust-read compatibility tests where practical.
   
   ### Out of scope
   
   To keep the contribution reviewable and fail-closed:
   
   - field aggregation inside partial-update sequence groups;
   - DELETE / UPDATE_BEFORE and remove-record semantics;
   - Rust writer support for sequence-group tables.
   
   The writer and Rust CREATE/ALTER paths should continue to reject 
sequence-group options until their semantics are implemented separately.
   
   ### Willingness to contribute
   
   I'm willing to submit a PR for this scoped read-side support.
   


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