fix: stop metric views re-altering on every run under view_update_via_alter - #1546
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…_alter MetricViewQueryConfig.get_diff compared the model's compiled YAML against the server's stored View Text with a whitespace-only text comparison. Databricks re-renders the stored definition (requoting `source` double->single, rewriting flow-style lists to block style), so the comparison always reported a change and dbt re-issued `ALTER VIEW ... AS` on every run for metric views configured with view_update_via_alter. Compare the parsed YAML structurally instead, falling back to the whitespace- normalized text comparison when a definition is not valid YAML. Adds unit tests for the quote and list-style cases and a functional regression asserting an unchanged metric view is not re-altered on re-run.
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/integration-test |
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Integration tests dispatched for PR #1546 by @sd-db. Track progress in the Actions tab. |
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Integration results for PR #1546 — UC cluster ✅ success · SQL warehouse ❌ failure · All-purpose cluster ✅ success · Shard coverage ✅ success |
jprakash-db
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Single integration test failure is for a known flaky test which can be ignored |
…-perpetual-alter # Conflicts: # CHANGELOG.md # tests/functional/adapter/metric_views/fixtures.py
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Description
Metric views configured with
view_update_via_alter=truere-issued a redundantALTER VIEW ... ASon everydbt run, even when the definition was unchanged.MetricViewQueryConfig.get_diffcompared the model's compiled YAML against the server's storedView Textwith a whitespace-only text comparison. Databricks re-renders the stored definition on read-back — it requotessourcefrom double to single quotes and rewrites flow-style lists (e.g.synonyms: [a, b]) to block style — so the normalized strings never matched and dbt always saw a change.The fix compares the parsed YAML structurally (
yaml.safe_load), so quote style and flow/block list style no longer register as changes. It falls back to the previous whitespace-normalized text comparison when a definition isn't valid YAML. Genuine definition changes are still detected, so real updates still apply viaALTER/replace.Scope is specific to metric views: regular views / materialized views / streaming tables diff via
QueryConfigoverinformation_schema.views.view_definition, which for plain SQL is returned as submitted — verified that a regular view withview_update_via_alterdoes not perpetually diff.Testing
tests/unit/relation_configs/test_metric_view_config.py): newget_diffcases for double-vs-single-quotedsourceand flow-vs-block lists (both failed before the fix), plus semantic-difference-detected and unparseable-fallback cases.tests/functional/adapter/metric_views/test_metric_view_noop.py): a metric view withview_update_via_alteris unchanged across an identical re-run (information_schema.tables.last_altereddoes not advance).tests/functional/adapter/metric_views/suite (19) and the unit suite pass — no regressions.Checklist
CHANGELOG.mdand added information about my change to the "dbt-databricks next" section.