A financial report queries the same accounts table 10 times across a complex calculation. The report shows inconsistent totals because data changed mid-calculation. What isolation level solves this?

Use REPEATABLE READ isolation for the report transaction: BEGIN; SET TRANSACTION ISOLATION LEVEL REPEATABLE READ; -- All 10 queries here see the SAME consistent snapshot -- even if other transactions commit changes during the report COMMIT. With REPEATABLE READ: all queries in the transaction see the data as it was at the moment BEGIN was executed. No data changes by concurrent transactions are vi