[Backport 3.7] Validate materialized view subqueries against SQL grammar deny list (#5485)

[RyanL1997]

Description

Validate materialized view subqueries against SQL grammar deny list

Related Issues

Resolves #[Issue number to be closed when this PR is merged]

• Backport [Enhancement] Validate materialized view subqueries against SQL grammar deny list #5485

Check List

• New functionality includes testing.
• New functionality has been documented.
• New functionality has javadoc added.
• New functionality has a user manual doc added.
• New PPL command checklist all confirmed.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff or -s.
• Public documentation issue/PR created.

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PR Reviewer Guide 🔍

(Review updated until commit a3b1017)

Here are some key observations to aid the review process:

🧪 PR contains tests

🔒 No security concerns identified

✅ No TODO sections

🔀 No multiple PR themes

⚡ Recommended focus areas for review Null Pointer Risk If SQLQueryUtils.extractIndexDetails(sqlQuery) returns null, calling indexQueryDetails.getMvQuery() will throw a NullPointerException. This can occur if the query format is unexpected or malformed, causing validation to fail with an unclear error instead of a meaningful validation message. IndexQueryDetails indexQueryDetails = SQLQueryUtils.extractIndexDetails(sqlQuery); String mvQuery = indexQueryDetails.getMvQuery();

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PR Code Suggestions ✨

Latest suggestions up to a3b1017
Explore these optional code suggestions:

Category	Suggestion	Impact
Possible issue	Add null check for indexQueryDetails Add null check for indexQueryDetails before accessing getMvQuery() to prevent potential NullPointerException. The extractIndexDetails method might return null for malformed or unexpected query formats, which would cause a runtime exception when calling getMvQuery(). async-query-core/src/main/java/org/opensearch/sql/spark/validator/SQLQueryValidator.java [49-55] public void validateFlintExtensionQuery(String sqlQuery, DataSourceType dataSourceType) { IndexQueryDetails indexQueryDetails = SQLQueryUtils.extractIndexDetails(sqlQuery); - String mvQuery = indexQueryDetails.getMvQuery(); - if (mvQuery != null) { - validate(mvQuery, dataSourceType); + if (indexQueryDetails != null) { + String mvQuery = indexQueryDetails.getMvQuery(); + if (mvQuery != null) { + validate(mvQuery, dataSourceType); + } } } Suggestion importance[1-10]: 7 __ Why: Adding a null check for indexQueryDetails before accessing getMvQuery() is a reasonable defensive programming practice that prevents potential NullPointerException. However, without knowing the implementation of SQLQueryUtils.extractIndexDetails(), we cannot confirm if it can return null. The suggestion addresses a potential runtime issue but may be unnecessary if the method guarantees non-null returns.	Medium

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Previous suggestions

Suggestions up to commit 690c5a6

Category	Suggestion	Impact
Possible issue	Add null check for indexQueryDetails Add null check for indexQueryDetails before accessing getMvQuery(). If extractIndexDetails returns null, calling getMvQuery() will throw a NullPointerException. This could happen with malformed or unexpected query formats. async-query-core/src/main/java/org/opensearch/sql/spark/validator/SQLQueryValidator.java [49-55] public void validateFlintExtensionQuery(String sqlQuery, DataSourceType dataSourceType) { IndexQueryDetails indexQueryDetails = SQLQueryUtils.extractIndexDetails(sqlQuery); - String mvQuery = indexQueryDetails.getMvQuery(); - if (mvQuery != null) { - validate(mvQuery, dataSourceType); + if (indexQueryDetails != null) { + String mvQuery = indexQueryDetails.getMvQuery(); + if (mvQuery != null) { + validate(mvQuery, dataSourceType); + } } } Suggestion importance[1-10]: 7 __ Why: The suggestion correctly identifies a potential NullPointerException if extractIndexDetails returns null. However, without seeing the implementation of extractIndexDetails, we cannot confirm if this is a real issue. The suggestion is valid defensive programming practice, though it may be addressing a theoretical rather than actual problem.	Medium

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Persistent review updated to latest commit a3b1017