docs: add SCD/dimensional modeling reference for databricks-dbsql - #207
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…rrogate key patterns Adds skills/databricks-dbsql/references/dimensional-modeling.md covering: - SCD type selection decision table - Surrogate key strategies (IDENTITY column vs xxhash64 hash key) - Complete two-pass MERGE for SCD Type 2 (expire + insert, with correct LEFT JOIN guard) - SCD Type 6 hybrid pattern (Type 2 rows + current_* column refresh) - Liquid Clustering key guidance for dim/fact tables + Predictive Optimization enable syntax - DEEP CLONE for environment promotion (dev/staging/prod) - Common issues table Wires new file into databricks-dbsql SKILL.md Quick Reference and Reference Files tables. Regenerates manifest.json and all four plugin bundles via scripts/skills.py generate. Fills the gap identified in #-- (no assembled dimensional modeling implementation guide; best-practices.md covers architecture but leaves SCD implementations incomplete; SCD Type 6, hash surrogate keys, and Deep Clone were absent from the skill entirely). Signed-off-by: Dipayan Das <dipayandas.data@gmail.com>
dipayanthedata
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lennartkats-db and
simonfaltum
as code owners
July 11, 2026 07:19
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What
Adds skills/databricks-dbsql/references/dimensional-modeling.md — implementation
patterns for SCD Type 1/2/6, surrogate keys (IDENTITY vs hash), Liquid Clustering
promotion. Wires the new reference into the parent SKILL.md.
Why
The existing skill covers architecture (best-practices.md) and streaming CDC
(databricks-pipelines) but had no batch SQL implementation guide for SCD patterns
— Type 2 was previously a one-line comment, Type 6, hash surrogate keys, and Deep
Clone promotion were absent entirely.
Verification
All Databricks-specific syntax and behavior claims were checked against current
docs.databricks.com pages (predictive optimization, Delta/Iceberg clone, identity
columns, Lakeflow pipeline limitations) as of July 2026 — sources noted inline
where non-obvious. The SCD Type 2 two-pass MERGE was hand-traced against a 3-row
worked example (initial load, one changed row, one net-new row) since no live
warehouse was available in this environment to execute it directly; a maintainer
should run it once against real data before merge.
python3 scripts/skills.py generateandvalidateboth pass clean.Notes for reviewers
happy to have this migrated/adapted however fits your internal process.
extract; it does not handle delete detection (documented as a caveat in the file).