Test coverage: non-SQL-Server TDS endpoints (Synapse dedicated + on-demand, Fabric DW, Dataverse)

[priyankatiwari08]

Summary

We have no public CI coverage for TDS endpoints that are not SQL Server / Azure SQL DB. These endpoints speak TDS but do not accept every hardcoded T-SQL statement the driver issues, so behavioral differences only surface in the field.

Raised during review of #4330 by @benrr101 and @edwardneal.

Why this matters

Two properties make these endpoints distinct from an average SQL Server instance:

1. They expose a TDS endpoint but behave just differently enough that hardcoded statements issued by SqlClient aren't guaranteed to be compatible.
2. Documentation is sometimes incomplete or fails to distinguish between variants. For example, HAS_PERMS_BY_NAME is not documented as supported in Synapse dedicated SQL pools but is available nonetheless.

Concrete examples already known:

• Synapse dedicated pools reject SET TRANSACTION ISOLATION LEVEL for every level except READ UNCOMMITTED (error 104409). Serverless/on-demand pools accept it like any other Azure SQL endpoint — so the two variants need separate coverage, not one "Synapse" leg.
• Dataverse rejects isolation level changes entirely.

#4330 works around the Synapse case with an endpoint guard, but that defense is specific to one statement and does not generalize.

Requested coverage

Endpoint	Notes
Azure Synapse — dedicated SQL pool	Distinct behavior from on-demand; needs its own leg
Azure Synapse — on-demand / serverless
Microsoft Fabric Data Warehouse	Including the new TDS bulk copy support
Microsoft Dataverse TDS endpoint

Expectation is that a handful of existing tests will fail against these back ends initially. Triaging those failures is part of the work — some will be genuine driver issues, others will need conditional gating.

Related

• Reset session isolation level on pool return (fixes #96) #4330 — added ADP.IsAzureSynapseDedicatedPoolEndpoint guard; review discussion that prompted this issue

[github-actions]

🔍 Triage Summary

Check	Result
Issue type	Task
Environment	N/A — this is a CI/test infrastructure task, not a bug report
Area	Area\Tests
Duplicates	None found
Regression	Not indicated

Analysis

This issue requests public CI coverage for non-SQL-Server TDS endpoints (Azure Synapse dedicated pool, Synapse serverless/on-demand, Microsoft Fabric Data Warehouse, and Microsoft Dataverse). These endpoints implement the TDS protocol but have behavioral differences — for example, Synapse dedicated pools reject most SET TRANSACTION ISOLATION LEVEL statements — that currently go untested. The issue was raised during review of #4330, which already introduced an endpoint guard as a point fix. The affected component is the CI/CD pipeline and manual/integration test infrastructure. Severity is P2 — no customers are blocked today, but driver defects against these endpoints can only be caught in the field without this coverage.

Next Steps

• Add separate CI legs for each of the four endpoints listed: Synapse dedicated pool, Synapse serverless/on-demand, Fabric DW, and Dataverse. Do NOT collapse dedicated and on-demand Synapse into one leg — their behaviors differ.
• Audit existing integration tests (especially isolation-level, transaction, and login-path tests) against each new backend. Expect some failures; classify them as genuine driver bugs or tests that need conditional gating.
• Fabric DW leg should include coverage for TDS bulk copy support introduced alongside the Fabric endpoint.
• Consider building on the ADP.IsAzureSynapseDedicatedPoolEndpoint pattern from Reset session isolation level on pool return (fixes #96) #4330 for any new endpoint-guard utilities needed during remediation.
• Assign to Copilot coding agent to scaffold the new pipeline legs and test conditional gates, starting with the Synapse dedicated pool case as it has the most concrete known failure (error 104409 on SET TRANSACTION ISOLATION LEVEL).

Note: This triage summary is auto-generated by an AI agent. The analysis and suggestions above have not been verified by a human maintainer. Please treat as preliminary guidance only.

Generated by SqlClient Issue Auto-Triage for issue #4580 · 30 AIC · ⌖ 6.44 AIC · ⊞ 8.6K · ◷