Fundamentals Of Database Engineering By Hussein Nasser Fix <INSTANT>

SELECT FOR UPDATE , foreign key checks, and DDL. 10. Monitoring and Observability You cannot fix what you cannot measure. Every database engineer must monitor:

Index what you query by. Don't index blindly. 3. Write Path: How Data Persists Understanding the write path explains durability and performance. fundamentals of database engineering by hussein nasser

| Metric | Why | |--------|-----| | | Throughput baseline | | Slow query log | Find bad queries | | Cache hit ratio | >99% is good, <95% means undersized cache | | Replication lag (in seconds) | Avoid stale reads | | Disk IOPS and latency | Often the real bottleneck | | Connection count | Too many = resource exhaustion | SELECT FOR UPDATE , foreign key checks, and DDL

By Hussein Nasser (Inspired Style) Introduction: What is Database Engineering? When most developers think of databases, they think of writing SQL queries or using an ORM. Database engineering is different. It’s the discipline of understanding how databases work under the hood: storage, indexing, memory management, replication, failover, and isolation. Every database engineer must monitor: Index what you