A database engineer doesn’t just use a database; they , tune , and troubleshoot it. They know why a query is slow, why a replica fell behind, or why VACUUM in PostgreSQL didn’t reclaim space.
READ COMMITTED is sufficient for most apps. SERIALIZABLE is expensive and often overused. fundamentals of database engineering by hussein nasser
Every index speeds up SELECT but slows down INSERT / UPDATE / DELETE . Each write must update every index. A database engineer doesn’t just use a database;
What if the power fails after step 1 but before step 3? Solution: On recovery, replay the WAL. why a replica fell behind
A database engineer doesn’t just use a database; they , tune , and troubleshoot it. They know why a query is slow, why a replica fell behind, or why VACUUM in PostgreSQL didn’t reclaim space.
READ COMMITTED is sufficient for most apps. SERIALIZABLE is expensive and often overused.
Every index speeds up SELECT but slows down INSERT / UPDATE / DELETE . Each write must update every index.
What if the power fails after step 1 but before step 3? Solution: On recovery, replay the WAL.