A schema is a formal description of a data asset’s structure: its fields, types, and relationships. Inspecting the source schema reveals how a sample was formed, where data problems may exist, and what ETL work delivery will require. section 2.4
Treat schema inspection as a pre-project delivery checkpoint:
- Identify every source table or data asset contributing to the sample. section 2.4
- Record whether the sample is a flat table joined from underlying databases or reflects the source structure. section 2.4
- Check update speed, arrival volume, migrations, quality campaigns, ownership, and undocumented manual preparation steps. section 2.4
- Convert schema findings into ETL, access, security, privacy, and resourcing tickets. section 2.4
Joined sample table
A large flat sample may conceal joins across several underlying databases. Comparing its fields and relationships with the source schema can expose missing context and integration work before delivery begins. section 2.4
