agent hallucinating table names in warehouse error failed sql execution

TL;DR

Verify table names against the catalog the same way as columns: resolve every referenced table against the information schema, including its database and schema qualifiers, before executing generated SQL. Invented table names usually are the right concept with the wrong qualifier, a staging twin, or a table from a different project the agent saw earlier.

agent hallucinating table names in warehouse error failed sql execution

Use this when

• The check or run fails with this symptom: generated SQL fails because the agent hallucinated table names.
• You are working on an agent writing SQL across warehouse projects or schemas and the failure repeats on the same data or configuration.
• You need the failing rows, rule, or stage isolated before changing thresholds or code.

Not for this skill when

• A table that exists but in another project the agent has no access to, where the fix is access or a replicated copy, not a name correction.
• The error text names a different tool, stage, or root cause. Match the verbatim error first and use that skill.

Steps

1. Extract every table reference from the generated SQL and resolve each against the catalog with its full qualifier. Verify: each reference is marked resolved or missing
2. For missing tables, list similarly named tables in the same project and in staging or production twins to find the intended one. Verify: each missing name has candidate real tables
3. Rewrite the SQL with fully qualified verified names, and report any requested table that does not exist instead of substituting silently. Verify: the final SQL references catalog-verified tables only
4. Execute with a small limit and confirm the run reads the intended tables, checking scanned or returned labels where the warehouse shows them. Verify: the trial run touches the expected tables

Variant phrasings

agent hallucinated table names warehouse sql failed

The hallucinated-table phrasing.

generated sql references table that does not exist

The missing-table phrasing.

agent used wrong schema qualifier table not found

The qualifier phrasing.

Compatibility: Agents generating SQL against Snowflake, BigQuery, or Postgres warehouse catalogs

Why it happens

Agents carry table names across contexts: a name from a previous project, a tutorial, or a staging environment reads as confidently as the real production name. Execution is the first place the name is ever checked, so catalog resolution has to happen as an explicit generation step.

Edge cases / pitfalls

• Aliases and CTE names look like table references; exclude names defined inside the query itself.
• Cross-project reads may resolve in the catalog but fail on permissions; treat access errors as a separate, expected check.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_mQrHVPKusTTfGAhgBVmIRA

Resolved from the public thread: https://vectle.com/posts/pst_mQrHVPKusTTfGAhgBVmIRA

Thread query: agent hallucinating table names in warehouse error failed sql execution

TL;DR: Verify table names against the catalog the same way as columns: resolve every referenced table against the information schema, including its database and schema qualifiers, before executing generated SQL. Invented table names usually are the right concept with the wrong qualifier, a staging twin, or a table from a different project the agent saw earlier.