Fix SQL explain API rejecting ?format=json parameter by gingeekrishna · Pull Request #5607 · opensearch-project/sql

gingeekrishna · 2026-07-05T06:14:29Z

Description

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

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github-actions · 2026-07-05T06:15:29Z

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gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

gingeekrishna · 2026-07-05T06:14:29Z

Description

Fixes#4373

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

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github-actions · 2026-07-05T06:15:29Z

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🧪 PR contains tests
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gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

gingeekrishna · 2026-07-05T06:14:29Z

Description

Fixes#4373

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

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github-actions · 2026-07-05T06:15:29Z

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🧪 PR contains tests
🔒 No security concerns identified
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gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

gingeekrishna · 2026-07-05T06:14:29Z

Description

Fixes#4373

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

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Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

github-actions · 2026-07-05T06:15:29Z

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🧪 PR contains tests
🔒 No security concerns identified
✅ No TODO sections
🔀 No multiple PR themes
⚡ No major issues detected

gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

gingeekrishna · 2026-07-05T06:14:29Z

Description

Fixes#4373

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

Copilot

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

github-actions · 2026-07-05T06:15:29Z

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🧪 PR contains tests
🔒 No security concerns identified
✅ No TODO sections
🔀 No multiple PR themes
⚡ No major issues detected

gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

gingeekrishna · 2026-07-05T06:14:29Z

Description

Fixes#4373

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

Copilot

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

github-actions · 2026-07-05T06:15:29Z

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🧪 PR contains tests
🔒 No security concerns identified
✅ No TODO sections
🔀 No multiple PR themes
⚡ No major issues detected

gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

gingeekrishna · 2026-07-05T06:14:29Z

Description

Fixes#4373

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

Copilot

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

github-actions · 2026-07-05T06:15:29Z

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🧪 PR contains tests
🔒 No security concerns identified
✅ No TODO sections
🔀 No multiple PR themes
⚡ No major issues detected

gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

gingeekrishna · 2026-07-05T06:14:29Z

Description

Fixes#4373

Problem: Since OpenSearch 3.0, calling POST /_plugins/_sql/_explain?format=json returns:

{
"error": {
"reason": "Invalid SQL query",
"details": "Failed to create executor due to unknown response format: json",
"type": "IllegalArgumentException"
},
"status": 400
}

Root cause:isSupportedExplainFormat() in SQLQueryRequest.java only accepted "simple", "standard", "extended", and "cost" — "json" was never in the list. The explain endpoint itself always returns JSON unconditionally (the format parameter has no effect on the response), so "json" was effectively accepted before this validation was tightened.

Fix: Add "json" to isSupportedExplainFormat(). The explain response path in SQLPlugin.java uses JsonResponseFormatter<ExplainResponse> regardless of the format parameter, so this is a pure backward-compatibility fix with no behavioral change.

Changes

sql/src/main/java/.../SQLQueryRequest.java — add "json" to isSupportedExplainFormat()
sql/src/test/java/.../SQLQueryRequestTest.java — regression test asserting ?format=json is accepted on explain requests

Testing

29/29 tests pass in SQLQueryRequestTest.

isSupportedExplainFormat() only accepted "simple", "standard", "extended", and "cost" — excluding "json". Before OpenSearch 3.0, ?format=json was valid for the explain endpoint, so existing workflows that pass this parameter now receive: "Failed to create executor due to unknown response format: json" The explain endpoint already returns JSON unconditionally regardless of the format parameter, so accepting "json" is a pure backward- compatibility restoration with no behavioral change. Fixesopensearch-project#4373 Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

Copilot

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

github-actions · 2026-07-05T06:15:29Z

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🧪 PR contains tests
🔒 No security concerns identified
✅ No TODO sections
🔀 No multiple PR themes
⚡ No major issues detected

gingeekrishna · 2026-07-05T10:03:51Z

The enforce-label check is failing — a release label is required. Since this PR improves the error message for unsupported window functions (a UX/error-experience fix), the bugFix label would be appropriate. Could a maintainer add it? Thanks!

CopilotAI review requested due to automatic review settings July 5, 2026 06:14

gingeekrishna requested review from LantaoJin, RyanL1997, Swiddis, acarbonetto, ahkcs, anirudha, dai-chen, joshuali925, mengweieric, noCharger, penghuo, ps48, qianheng-aws, songkant-aws, vamsimanohar, ykmr1224 and yuancu as code owners July 5, 2026 06:14

CopilotAI reviewed Jul 5, 2026