Agent WranglersDEN-21Recommended
Give notice before removing a column people use
Treat the tables that dashboards and other teams read as a public interface. Add columns freely, but keep a renamed or removed column for at least 30 days after notice.
How to do it
It is the same pattern as Version only for breaking changes and Expand first and contract later. Add the new column, mark the old one as deprecated in the metadata, and tell its readers from the lineage graph. The warehouse's query history shows who still reads the old column. Remove it after the notice.
How to check
A script compares the mart schemas with the main branch and fails when a column disappears without a deprecation entry at least 30 days old.
Sources
Related rules
- API-28 Version only for breaking changes in API design
- DAT-22 Expand first and contract later in Data and databases
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