Job History Logs

Hi,
Maximum Job History Log size is set to 1000 and Maximum Job History Rows
Per Job is set to 100. There are some some jobs that are running every
minute. In less then five minute the Log Size grows to 45 from 0. So I guess
the jobs that are running every minute are filling up the History Log. When
other jobs that run once every night are not able to write in the History
Log. What should be the preferred setting in such scenario that will allow
the nightly jobs to write history in the History Log.
I can think of two options. I can either uncheck the Limit Size of Job
History Log option or change the value of the Maximum Job History Log Size
option. But then I don't know how large the History Log will grow. Can you
give me an idea on that? Also is there a way to automatically clear the
History Log?
Thanks in advance...
If you have n number of jobs then set history log size to (n * 100) +
100.
Set maximum number of rows per job to 100.
Regards
Amish Shah.