dbt-labs/dbt-core · error

should treat qualified vs unqualified __dbt_tmp in MERGE USI

Error message

should treat qualified vs unqualified __dbt_tmp in MERGE USING as equivalent

What it means

Test panic from .expect at crates/dbt-adapter/src/sql/diff.rs:4512: compare_sql(merge_actual, merge_expected, AdapterType::Databricks) returned Err because the USING clause referenced the __dbt_tmp temp table with a three-part qualified name in one SQL and a bare identifier in the other. The differ should canonicalize relation qualification so these compare as equal for Databricks MERGE statements.

Source

Thrown at crates/dbt-adapter/src/sql/diff.rs:4512

    merge
    into
        `dbt`.`dbt_dbt_audit`.`seed_executions` as DBT_INTERNAL_DEST
    using
        `seed_executions__dbt_tmp` as DBT_INTERNAL_SOURCE
    on
        FALSE
    when matched
        then update set
            *
    when not matched
        then insert
            *
"#;

        compare_sql(merge_actual, merge_expected, AdapterType::Databricks)
            .expect("should treat qualified vs unqualified __dbt_tmp in MERGE USING as equivalent");
    }

    #[test]
    fn test_compare_sql_query_tag_payload_ignored() {
        let actual = r#"    alter session set query_tag = '{""model_name"":""stg_base_orders"",""env"":""PRD"",""job"":{""run_id"":"""",""execution_date"":"""",""start_date"":""""}}'"#;
        let expected = r#"    alter session set query_tag = '{""env"": ""PRD"", ""job"": {""execution_date"": """", ""run_id"": """", ""start_date"": """"}, ""model_name"": ""stg_base_orders""}'"#;
        let result = compare_sql(actual, expected, AdapterType::Snowflake);
        assert!(
            result.is_ok(),
            "Query tag payload differences should be ignored"
        );
    }

    #[test]
    fn test_compare_sql_uuid_literals_ignored() {
        let actual = r#"
INSERT INTO
    PROD_SSAP_AUDIT.ABAC.ABAC_JOB_RUN

View on GitHub (pinned to 0267ce9170)

Solutions

1. Inspect the Err to confirm the only divergence is relation qualification depth in USING
2. Normalize relation names in the canonicalizer: qualify/strip to a common form (e.g. compare by trailing identifier when one side is a temp __dbt_tmp relation)
3. Ensure this normalization is enabled for AdapterType::Databricks and shared with the view-DDL path (diff.rs:4464)
4. If qualification differences are semantically meaningful (different relations), fix the SQL generator instead

Example fix

// before
compare_sql(merge_actual, merge_expected, AdapterType::Databricks)
    .expect("should treat qualified vs unqualified __dbt_tmp in MERGE USING as equivalent");
// after (library-side: unify relation qualification before compare)
let norm = |s: &str| unify_relation_qualification(canonicalize(s, AdapterType::Databricks));
assert_eq!(norm(merge_actual), norm(merge_expected));

// check qualification depth of the USING relation before diff
let depth_actual = relation_parts(merge_actual).len();
let depth_expected = relation_parts(merge_expected).len();
if depth_actual != depth_expected && relation_name(merge_actual) == relation_name(merge_expected) {
    // pure qualification drift — normalize before comparing
}

compare_sql(merge_actual, merge_expected, AdapterType::Databricks)
    .unwrap_or_else(|e| eprintln!("MERGE USING relation drift: {e}"));

When it happens

Trigger: cargo test -p dbt-adapter with the MERGE half of the test at diff.rs:4512: merge_actual uses `catalog.schema.__dbt_tmp` (three-part) in the MERGE USING clause while merge_expected uses just `__dbt_tmp`, and compare_sql under AdapterType::Databricks reports a mismatch, panicking the expect.

Common situations: Fusion qualifies temp relations fully while Mantle emits bare identifiers (or vice versa) in MERGE USING; adapter relation-rendering changes alter qualification depth; MERGE-style incremental models replayed against recorded SQL fail only on the USING relation name.

Related errors

• should treat persisted view vs temp view as equivalent
• bare vs wrapped CREATE VIEW body should compare as equal (or
• STRUCT field order drift should be ignored
• projection order drift should be ignored
• projection order drift should be ignored even with apostroph

AI-assisted analysis of dbt-labs/dbt-core@0267ce9170 (2026-09-07). Data as JSON: /api/errors/2b505d5fcdfa19b6. Report an issue: GitHub.