053-445

To set the history retention period for either window logging or job logging individually, which parameters of the SET_SCHEDULER_ATTRIBUTE procedure need to be used? (Choose all that apply.)
A. LOG_HISTORY
B. JOB_LOG_RETENTION
C. WINDOW_LOG_RETENTION
D. WHICH_LOG
E. LOG_NAME

　　The LOG_HISTORY parameter defines the retention period for both job logging and window logging by default.However,the WHICH_LOG parameter can be used to specify either JOB_LOG or WINDOW_LOG.
PURGE_LOG Procedure
By default, the Scheduler automatically purges all rows in the job log and window log that
are older than 30 days. The PURGE_LOG procedure is used to purge additional rows from
the job and window log.
Rows in the job log table pertaining to the steps of a chain are purged only when the entry
for the main chain job is purged (either manually or automatically).
Syntax

DBMS_SCHEDULER.PURGE_LOG(log_history IN PLS_INTEGER DEFAULT 0,
which_log IN VARCHAR2 DEFAULT 'JOB_AND_WINDOW_LOG',
job_name IN VARCHAR2 DEFAULT NULL);

Parameters
Table 129-69 PURGE_LOG Procedure Parameters

log_history	This specifies how much history (in days) to keep. The valid range is 0 - 1000000. If set to 0, no history is kept.
which_log	This specifies the log type. Valid values are: job_log, window_log, and job_and_window_log.
job_name	This specifies which job-specific entries must be purged from the jog log. This can be a comma-delimited list of job names and job classes. Whenever job_name has a value other than NULL, the which_log argument implicitly includes the job log

Usage Notes

This procedure requires the MANAGE SCHEDULER privilege.
Examples
The following completely purges all rows from both the job log and the window log:
DBMS_SCHEDULER.PURGE_LOG();
The following purges all rows from the window log that are older than 5 days:
DBMS_SCHEDULER.PURGE_LOG(5, 'window_log');
The following purges all rows from the window log that are older than 1 day and all rows
from the job log that are related to jobs in jobclass1 and older than 1 day:
DBMS_SCHEDULER.PURGE_LOG(1, 'job_and_window_log', 'sys.jobclass1');