[dwaddle]

Problem

In databend_sqlalchemy/databend_dialect.py, visit_create_index and visit_drop_index return empty strings (""). In connector.py, execution of empty statements is swallowed (if not operation: return).

As a result, executing Index("ix_t_b", table.c.b).create(conn) or dropping an index returns normally with zero warnings and zero exceptions, leading callers and migration tooling to assume the index was successfully created when Databend does not support standard secondary indexes.

Solution

Raise an explicit sqlalchemy.exc.CompileError in both visit_create_index and visit_drop_index:

• Clarifies that standard secondary indexes are not supported by Databend.
• Suggests native alternatives supported by Databend (CLUSTER BY or INVERTED INDEX).
• Eliminates silent false successes in migration scripts and index management code.

Verification

• Added test_create_and_drop_index_raises_compile_error in tests/unit/test_databend_dialect.py verifying that compiling CreateIndex or DropIndex against DatabendDialect raises CompileError with descriptive diagnostic messages.
• Verified 100% test pass via pytest.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-21T12:43:30.670539Z	b78e2de	PR opened

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