docs: add parquet.case_insensitive parameter for file sources

[Copilot]

Description

Documents the new parquet.case_insensitive option for file sources (S3, Azure Blob, GCS). This parameter enables case-insensitive column name matching when reading Parquet files, addressing the common scenario where Parquet files use mixed-case column names (e.g., ID, Name) but PostgreSQL schemas default to lowercase.

Changes:

• Added parquet.case_insensitive parameter documentation to S3, Azure Blob, and GCS source pages
• Updated formats-and-encoding-options.mdx Parquet section with case-insensitive matching explanation
• Added SQL examples demonstrating the parameter usage
• Fixed pre-existing SQL syntax errors in GCS examples (missing commas)

Parameter behavior:

• Default: false (maintains backward compatibility)
• When true: enables case-insensitive matching (e.g., column id matches Parquet column ID)
• Ambiguous matches (multiple columns match case-insensitively) are ignored

Example:

CREATE TABLE s(
    id int,
    name varchar,
    age int
)
WITH (
    connector = 's3_v2',
    match_pattern = '*.parquet',
    s3.region_name = 'ap-southeast-2',
    s3.bucket_name = 'example-bucket',
    parquet.case_insensitive = 'true'
) FORMAT PLAIN ENCODE PARQUET;

Related code PR

risingwavelabs/risingwave#24734

Related doc issue

Tracks documentation for the merged PR #24734 which added the parquet.case_insensitive option for file sources.

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(source): add Parquet case-insensitive column matching option for file source</issue_title>
<issue_description>This issue tracks the documentation update needed for the merged PR risingwavelabs/risingwave-docs#24734.

Source PR URL: risingwavelabs/risingwave#24734
Source PR Merged At: 2026-02-11T10:23:48Z

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(source): add Parquet case-insensitive column matching option for file source #971

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