Use intermediate-and-swap pattern in full-refresh incremental path#398
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sdebruyn wants to merge 1 commit into
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Use intermediate-and-swap pattern in full-refresh incremental path#398sdebruyn wants to merge 1 commit into
sdebruyn wants to merge 1 commit into
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The full-refresh branch of fabric__incremental dropped the existing target before re-creating it. If the subsequent CREATE TABLE AS SELECT failed for any reason — transient Fabric error, query timeout, broken model SQL, capacity throttling, OOM, network hiccup — the user was left with no target table at all. Build the new table into an intermediate relation first, then rename the existing target to a backup, rename the intermediate to the target, and drop the backup. If the build fails, the existing target stays in place. This is the same pattern dbt-postgres, dbt-snowflake, and dbt-spark use.
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Fixes #397.
The full-refresh branch of
fabric__incrementaldropped the existing target before re-creating it, so a transient Fabric error, query timeout, capacity throttling event, OOM, or network hiccup during the CTAS step left the user with no target table at all. Downstream BI dashboards and reports point at nothing until the next dbt run completes successfully.Change
Adopt the intermediate-relation + backup-and-swap pattern that dbt-postgres, dbt-snowflake, dbt-spark, and dbt-bigquery use:
make_intermediate_relation(target_relation)). If this fails, the existing target stays untouched.Leftover intermediate / backup / temp-view relations from a previous failed run are dropped before the build, matching the existing cleanup pattern.
Testing
Happy to extend the change with an integration test that injects a CTAS failure during
--full-refreshand asserts the previous target is still queryable, if that's the preferred follow-up.