Tools and Utilities - Expert Oracle RAC Performance Diagnostics and Tuning - page 193

Based on the example, the trace file will contain information (SQL statements, wait events encountered, bind
variables, and bind values). This trace information can be scanned through and extracted by action type using the
trcsess utility, and once extracted into a single file, it can be analyzed using the tkprof utility.

trcsess output=trcUPDATE.trc service=TAPS module='Process Orders' action=UPDATE SSKY1_ora_*.trc
trcsess [output=<output file name >] [session=<session ID>] [clientid=<clientid>]
[service=<service name>] [action=<action name>] [module=<module name>] <trace file names>

The parameters with a short description, used to generate the output using trcess , are listed below:
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<output file name> output destination default being standard output.

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<sessionID> session to be traced. Session id is a combination of session index and session
serial number.

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<clientid> to be traced.

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<service name> service to be traced.

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<action name> action to be traced.

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<module name> module to be traced.

<trace file names> is a space-separated list of trace files with wild card * supported.
The following trcsess command will extract trace information from the trace file that pertains to service SRV1
but contains all modules and actions:

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trcsess output=trcTAPS.trc service=TAPS SSKY1_ora*.trc

Similarly, the following trcsess command will extract trace information from the trace files that pertains to
service TAPS and module 'Process Orders' but contains all actions:

trcsess output=trcRead.trc service=TAPS module='Process Orders' SSKY1_ora*.trc

Once the trace files are consolidated using the trcsess utility, a report can be generated using the TKPROF utility
discussed earlier.

Oracle's Wait Interface
In the AWR report discussions earlier, we mentioned the top five waits encountered by the database/application
during a specific snapshot period. We also discussed collecting wait events using 10046 at level 8 earlier. These wait
events are retrieved by the AWR process from certain data dictionary views and stored in AWR-specific tables.
Oracle's wait interface (OWI) helps to identify all wait events. This helps track the number of waits and the
amount of time waited for each event throughout the life of a session.
The data dictionary views that comprise the wait interface include

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GV$SYSTEM_EVENT

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GV$SESSION_EVENT

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GV$SESSION_WAIT

GV$EVENT_NAME
Unlike the AWR report that only reports information at the overall system level for the period of a snapshot, data
dictionary views such as the GV$SESSION_EVENT and GV$SESSION_WAIT provide information at the session level.

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