22.4 Oracle Database Wait Event Interface Improvements

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 Oracle Database 10 Grid   These V$ performance views have been added to:

• V$EVENT_NAME.   Class information is added allowing classification and links to other V$ performance views containing class columns. A class is a classification or category for a wait event or statistic as can be seen in the following query.

  SQL> SELECT DISTINCT(class) FROM v$event_name;     CLASS -------------------------------------------- Administrative Application Archival Process Scheduling Cluster Commit Concurrency Configuration Idle Managed Recovery Processing Scheduling Network Other Scheduler System I/O User I/O

• V$SESSION.   Has a lot more information in it including class and parameter details for direct hooks to the third layer and beyond of the Oracle Database Wait Event Interface.

These V$ performance views are new to Oracle Database 10g:

• V$SYSTEM_WAIT_CLASS. Aggregation layer wait times for classes.

• V$SESSION_WAIT_CLASS. As above but in the session layer.

• V$EVENT_HISTOGRAM. Waits and wait times event histogram.

• V$FILE_HISTOGRAM and V$TEMP_HISTOGRAM. Single block read histograms for data files and temporary files.

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