Oracle Database 12c Release 2 Performance Tuning Tips And Techniques -oracle Press- Direct
Analyzes how statistics are gathered and provides actionable recommendations to improve the accuracy of the query optimizer.
-- Wait events (system level) SELECT event, total_waits, time_waited, average_wait FROM V$SYSTEM_EVENT WHERE wait_class != 'Idle' ORDER BY time_waited DESC; Analyzes how statistics are gathered and provides actionable
Use AWR to collect and process performance metrics. For 12.2, you can now capture AWR data specifically for Pluggable Databases (PDBs) in multitenant environments. Analyzes how statistics are gathered and provides actionable
Use ASH for "near real-time" diagnostics to find transient performance spikes that AWR might miss. Analyzes how statistics are gathered and provides actionable
Use EXPLAIN PLAN or DBMS_XPLAN to analyze how the optimizer executes queries.
