docs: Add periodic refresh table jobs documentation (experimental)

[Copilot]

Description

Documents the new periodic refresh table jobs feature introduced in risingwavelabs/risingwave#23737. This experimental feature enables scheduled full reloads of Iceberg tables with refresh_mode = 'FULL_RELOAD'.

Changes:

• New command: REFRESH TABLE for manual refresh triggers
• New system catalog: rw_refresh_table_state for monitoring refresh job status
• Enhanced Iceberg ingestion: Added refresh_mode and refresh_interval_sec parameters for periodic reloads
• Updated feature matrix: Periodic loading now supported for both append-only and mutable Iceberg tables
• Clarified default behavior: Continuous ingestion marked as the default approach
• Important usage notes: FULL_RELOAD requires CREATE TABLE (not source), and data only loads after triggering a refresh
• Scheduler configuration: Added documentation for stream_refresh_scheduler_interval_sec config parameter

Example:

CREATE TABLE iceberg_batch_table (
    id int primary key,
    name varchar
) WITH (
    connector = 'iceberg',
    refresh_mode = 'FULL_RELOAD',
    refresh_interval_sec = '60',
    -- ... other Iceberg connector parameters
);

-- Manual refresh (required to load initial data)
REFRESH TABLE iceberg_batch_table;

-- Monitor status
SELECT table_id, current_status, last_trigger_time, trigger_interval_secs
FROM rw_catalog.rw_refresh_table_state;

All features marked as experimental per source PR requirements.

Related code PR

risingwavelabs/risingwave#23737

Related doc issue

Fix #815

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: add periodic refresh table jobs & refactor ProgressTracker</issue_title>
<issue_description>This issue tracks the documentation update needed for the merged PR risingwavelabs/risingwave-docs#23737.

Source PR URL: risingwavelabs/risingwave#23737
Source PR Merged At: 2025-11-24T08:59:25Z

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: add periodic refresh table jobs & refactor ProgressTracker #815

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[WanYixian]

@chenzl25 Please check the accuracy of the doc, thanks!

[chenzl25]

LGTM