SeniorSenior (6–10 yrs)SQLRedisMongoDBAmazonOracleJP Morgan
Isolation levels
Explain READ COMMITTED vs REPEATABLE READ vs SERIALIZABLE with anomalies prevented.
Answers use simple, clear English.
Audio N/AQuick interview answer
READ COMMITTED prevents dirty reads. REPEATABLE READ prevents dirty + non-repeatable reads (phantom handling varies by engine). SERIALIZABLE prevents phantoms too via range locks or SSI.
Detailed answer
READ COMMITTED prevents dirty reads. REPEATABLE READ prevents dirty + non-repeatable reads (phantom handling varies by engine). SERIALIZABLE prevents phantoms too via range locks or SSI. Higher isolation increases blocking/abort rates—pick per use case.
seniorarchitect#transactions#isolation