SQLHardofficialBenchmark eligiblepro
Expand-contract schema migration
A deploy created addresses and copied some customers. Others still have inline address columns. Complete the expand-contract: backfill, dual-write window, then drop inline columns only after hidden tests confirm parity.
| Field | Detail |
|---|---|
| Creator | PipelineArena · expert |
| Version | 2.0.0 |
| Time | 60 min |
| Credits | 5 |
| Completion | 0% · 0.0 rating |
| Hidden tests | 4 |
Objective
Target schema with no lost address data; every customer has an addresses row when they had inline data.
| # | Success condition |
|---|---|
| 1 | addresses backfilled from remaining inline columns |
| 2 | customers.address_id set |
| 3 | Inline address columns dropped only after backfill |
| 4 | Row counts conserved |
| # | Visible instruction |
|---|---|
| 1 | Inspect live vs expected schema. |
| 2 | Backfill first (expand). Do not drop columns until parity. |
| 3 | Forward-only completion script — no restore from backup. |
Hidden tests score the final tables or files, not the exact syntax you used. Test implementation is never shown to participants.
Signed-in workspace: Open in app