docs: add configurable Parquet writer properties for Iceberg sink and compaction

[Copilot]

Documents three new compaction.* sink parameters that control Parquet output for both Iceberg sink writes and compaction, and the deprecation of the old node-level storage config.

Description

• iceberg/maintenance.mdx

  • Added compaction.write_parquet_compression — Parquet codec (uncompressed, snappy, gzip, lzo, brotli, lz4, zstd; default: snappy)
  • Added compaction.write_parquet_max_row_group_rows — max rows per row group (default: 122880)
  • Updated compaction.target_file_size_mb description: now applies to both sink writes and compaction (not just compaction), with explicit default of 1024 MB
  • Both new params note ALTER SINK (dynamic update) support
  • Added deprecation warning: iceberg_compaction_write_parquet_max_row_group_rows storage config → use compaction.write_parquet_max_row_group_rows instead
  • Updated version note to call out v2.9.0 additions

• iceberg/iceberg-feature-support.mdx

  • Added Feb 2026 timeline entry for configurable Parquet writer properties

Example usage:

CREATE SINK my_iceberg_sink FROM my_table
WITH (
    connector = 'iceberg',
    type = 'append-only',
    'compaction.target_file_size_mb' = '256',
    'compaction.write_parquet_compression' = 'zstd',
    'compaction.write_parquet_max_row_group_rows' = '50000',
    -- ... other required fields ...
);

Related code PR

risingwavelabs/risingwave#24612

Related doc issue

https://github.com/risingwavelabs/risingwave-docs/issues/24614

Checklist

• I have run the documentation build locally to verify the updates are applied correctly.
• For new pages, I have updated mint.json to include the page in the table of contents.
• All links and references have been checked and are not broken.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Document: feat(connector): add configurable write-parquet-properties for Iceberg sink and compaction</issue_title>
<issue_description>This issue tracks the documentation update needed for the merged PR risingwavelabs/risingwave-docs#24612.

Source PR URL: risingwavelabs/risingwave#24612
Source PR Merged At: 2026-02-25T11:40:17Z

If it is a major improvement that deserves a new page or a new section in the documentation, please check if we should label it as an experiment feature.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Document: feat(connector): add configurable write-parquet-properties for Iceberg sink and compaction #1028

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