when running archivelog mode how to change log_archive_max_processes,which value should it be ?
Based on what other parameter or hardware enviorment ?
Use following command
ALTER SYSTEM SET LOG_ARCHIVE_MAX_PROCESSES=2
You should define number of ARCn processes depending on number of log files and database workload. For example, if you use 5 or more logfile groups and your database is very active you can use 2 or more Archivers.
Although LGWR can automaticly increase number of ARCn processes. You can define initial number with LOG_ARCHIVE_MAX_PROCESSES to insure ARCn can handle workload and to avoid overhead for starting new processes dynamically.