Updates for Stream Processing docs section

[eschabell]

stream-processing: tutorial: update Docker image tags to 4.2.3

  - Replace inconsistent outdated image tags (1.2, 1.4, 1.8.2) with 4.2.3
    across all six Docker commands
  - Fix contradictory version output in step 1 to match the image tag used

stream-processing: overview: distinguish stream processor from SQL processor

  - Add "Stream processor versus SQL processor" section explaining the two
    SQL-based query interfaces, their differences, and when to use each
  - Link to pipeline/processors/sql.md for the inline SQL processor

tream-processing: fluent-bit-sql: document missing features and fix errors

  - Add WINDOW HOPPING syntax to SELECT grammar block
  - Add two-item window type summary describing tumbling vs. hopping windows
  - Add TIMESERIES_FORECAST aggregation function with example
  - Add WINDOW HOPPING example query
  - Fix COUNT example SQL placeholder (X SECOND -> 5 SECOND) to match description
  - Add missing description for RECORD_TIME() function

Fixes #2399

Summary by CodeRabbit

Release Notes

• Documentation
  • Added WINDOW HOPPING option for overlapping time windows in stream processing queries
  • Introduced TIMERSERIES_FORECAST function with linear regression forecasting capability
  • Extended RECORD_TIME functionality to append record timestamps in double-format
  • Clarified differences between stream processor and SQL processor workflows
  • Updated tutorial examples to Fluent Bit version 4.2.3

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between dc38f3c and 1586311.

📒 Files selected for processing (3)

• stream-processing/fluent-bit-sql.md
• stream-processing/overview.md
• stream-processing/tutorial.md

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📝 Walkthrough

Walkthrough

Documentation updates refresh the stream processing section with extended SQL syntax for window operations, processor architecture clarification, and modernized Docker image references. Introduces WINDOW HOPPING, TIMERS/FORECAST functions, RECORD_TIME extensions, and distinguishes stream processor from SQL processor capabilities.

Changes

Cohort / File(s)	Summary
SQL Function and Syntax Extensions stream-processing/fluent-bit-sql.md	Expands SELECT syntax to include WINDOW HOPPING alongside WINDOW TUMBLING; adds TIMERS/FORECAST function with linear regression forecasting; documents RECORD_TIME with timestamp appending; updates COUNT example to explicitly reference tumbling window.
Processor Architecture Documentation stream-processing/overview.md	Adds new section distinguishing stream processor (independent subsystem with tag/match rules, aggregation, time windows) from SQL processor (inline pipeline, YAML-configured, per-record operations only).
Tutorial Version Updates stream-processing/tutorial.md	Updates Fluent Bit Docker image tags from legacy versions (1.2, 1.4, 1.8.2) to unified version 4.2.3 across command examples and sample outputs.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~15 minutes

Suggested reviewers

• cosmo0920
• patrick-stephens

Poem

🐰 Hops through the docs with glee,
Windows tumble, windows hop with spree,
SQL syntax shines so bright,
Stream processors take their flight,
Version four-point-two-point-three! ✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Title check	❓ Inconclusive	The title 'Updates for Stream Processing docs section' is generic and doesn't capture the specific changes made, such as Docker image version updates, SQL syntax additions, or the new processor comparison section.	Consider a more specific title like 'Update Stream Processing docs: Docker 4.2.3, WINDOW HOPPING, and processor clarifications' to better convey the main changes.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Linked Issues check	✅ Passed	The pull request successfully addresses all objectives from issue #2399: updates Docker image tags to 4.2.3, clarifies stream vs SQL processor differences, documents missing SQL features (WINDOW HOPPING, TIMESERIES_FORECAST, RECORD_TIME), and fixes errors in examples.
Out of Scope Changes check	✅ Passed	All changes are within scope of issue #2399: documentation updates for the Stream Processing section covering tutorial versioning, overview clarifications, and SQL feature documentation.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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• Create PR with unit tests
• Post copyable unit tests in a comment

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[eschabell]

@cosmo0920 and @patrick-stephens ready for review!

[eschabell]

Waited week on reviewers, merging.