Recognises greenfield DDL aimed at a populated database
https://knobit.org/id/knobit/K-822
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| Context functions | Result evaluation |
|---|---|
| Knobit creation methods | AI generated, human edited |
| Knobit types | Skill |
| LCG purposes | Assessing the learner's knowledge or skill state |
| LCG purposes | Selecting an assessment task or learning activity |
| action verb | Recognises en |
| applies knowledge | Explains schema migration and rollback |
| assessment criterion | Flags the deficient case and passes the acceptable one. Deficient: `account_number` tightened to `NOT NULL` in the model and the regenerated DDL given to the release; 3 % of migrated accounts have no IBAN, the deploy fails halfway, and the schema is left with half its constraints applied Acceptable: The regenerated DDL diffed against the previous version as the statement of intent, and the migration hand-written for that diff where deployment lives (Flyway, Liquibase, dbt, Alembic) with backfill and rollback — then verified by rebuilding an empty database from the generated DDL and comparing it with the migrated one en |
| assessment method | skill-tests task: Generated DDL review, Postgres and Snowflake (DDL review skills) en |
| dcterms:identifier | K-822 |
| dcterms:license | https://creativecommons.org/licenses/by/4.0/ |
| dcterms:source | Review checklist 05-ddl, row 22; Ambler & Sadalage 2006; this skill (08-ddl.md) en |
| expected result | The changes needing a backfill and a migration en |
| rdfs:label | Recognises greenfield DDL aimed at a populated database en |
| schema:creativeWorkStatus | accepted |
| schema:isPartOf | Data modelling (DAMA-DMBOK2) |
| skos:altLabel | Greenfield DDL run against a populated database (generated DDL) en |
| skos:definition | `08-ddl/` handed to a release for an environment that already has data. This output builds a schema from nothing. The changes that look smallest in the diff are the ones that need a backfill plan — a nullable column tightened to `NOT NULL`, a widened or narrowed type, a split column — and on Databricks `ALTER TABLE ... ADD CONSTRAINT` validates the existing rows and fails on the first violation. en |
| skos:prefLabel | Recognises greenfield DDL aimed at a populated database en |
| target object | generated DDL for a release en |
Used by
| includes knobit | Generates DDL per target dialect and reviews it against model, engine, data and deployment |
|---|---|
| requires knobit | Generate and review DDL |