Backfills

Suppose the job that builds a daily usage table from smart meter readings has had a bug for 18 months, and the fix was merged this morning. Which past days would you run again? In what order, how many at a time, and what would readers of the table see meanwhile?

Running a pipeline again over past periods with corrected code (a backfill) starts with answering those four questions. This lesson answers them for one bug in the meter pipeline from ETL and ELT. Every query below was run on MySQL 8