ASH table data collection

After the x$ structures are materialized in the v$active_session_history and v$session_wait_history views, a new AWR snapshot transfers (and aggregates) the vents into corresponding dba_hist_active_sess_history and other dba_hist tables. Table 16.1 below shows some of the most important Oracle10g ASH wait event tables:

dba_hist_active_session_history
dba_hist_active_session_history_bl
dba_hist_bg_event_summary
dba_hist_event_name
dba_hist_metric_name
dba_hist_sessmetric_history
dba_hist_sys_time_model
dba_hist_sys_time_model_bl
dba_hist_sysmetric_history
dba_hist_sysmetric_summary
dba_hist_sysstat
dba_hist_sysstat_bl
dba_hist_system_event
dba_hist_system_event_bl
dba_hist_waitclassmetric_history
dba_hist_waitstat
dba_hist_waitstat_bl

Table 16.1: Oracle10g wait event dba_hist tables

The following section begins with a quick review of Oracle wait events in order to assist users’ understanding of how they can help identify and tune bottlenecks in the database.
 

---

This is an excerpt from my latest book "Oracle Tuning: The Definitive Reference".  You can buy it direct from the publisher for 50%-off and get instant access to the code depot of Oracle tuning scripts: