USE THIS SKILL WHENEVER the user mentions database is slow / hung / high CPU, performance tuning, SQL tuning, execution plan / explain plan, AWR / ADDM / ASH, SQL Tuning Advisor, SQL profile, SQL plan baseline (SPM), SPA / SQL Performance Analyzer, optimizer statistics / DBMS_STATS / histograms / data skew, top SQL / resource consumers, blocking locks / runaway / kill session, wait event / wait class analysis, latch / mutex / "cursor: pin S" / "cache buffers chains" contention, SGA / PGA / memory tuning, optimizer parameters (optimizer_*, cursor_sharing, OFE), parallel execution / PX downgrades, real-time SQL monitoring, Database Replay (RAT / workload capture & replay), …
