improve list in the subquery optimization

[hawkingrei]

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ref #21869

Improve the sample list here so that customers don't mistakenly think content is missing.

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[gemini-code-assist]

Summary of Changes

Hello @hawkingrei, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refines the documentation for subquery optimization by expanding the list of recognized subquery patterns. Specifically, it introduces the ALL operator case and reorganizes the existing entries to enhance clarity and completeness for users learning about subquery optimizations.

Highlights

• Documentation Enhancement: Added a new subquery pattern involving the ALL operator to the list of subquery situations in the subquery-optimization.md document.
• Content Reordering: Reordered the existing list of subquery situations for improved logical flow and readability within the documentation.

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[gemini-code-assist]

Code Review

This pull request aims to improve the list of subquery situations in the documentation. The change adds a case for ALL subqueries and reorders the list slightly. My review focuses on further improving this list for clarity, consistency, and completeness. I've suggested a reorganization that groups related items, corrects a minor typo, and uses more general terms for better readability.

[gemini-code-assist]

For better readability and consistency, I suggest reorganizing and clarifying this list.

• The current list has a minor typo (.. instead of ...).
• The order can be improved by grouping related operators.
• For quantified comparisons, we can generalize the operators and include ANY and SOME for completeness.
• Using comparison_operator is cleaner than listing out individual symbols.

Here is a suggested improvement:

Suggested change

	- `... </=/!=/>/ ALL (SELECT ... FROM ...)`
	- `NOT IN (SELECT ... FROM ...)`
	- `NOT EXISTS (SELECT ... FROM ...)`
	- `IN (SELECT ... FROM ..)`
	- `NOT EXISTS (SELECT ... FROM ...)`
	- `EXISTS (SELECT ... FROM ...)`
	- `... >/>=/</<=/=/!= (SELECT ... FROM ...)`
	- `IN (SELECT ... FROM ...)`
	- `NOT IN (SELECT ... FROM ...)`
	- `EXISTS (SELECT ... FROM ...)`
	- `NOT EXISTS (SELECT ... FROM ...)`
	- `... comparison_operator [ANY | ALL | SOME] (SELECT ... FROM ...)`
	- `... comparison_operator (SELECT ... FROM ...)`