RE: Resource Manager Plans and SYSTEM_GROUP

In answer to your question: Whenever you have significant user batch load that runs during any automatic system stats gathering and so forth. You don’t want to make the user work overdue or have batch operations intrude on heavy interactive windows for marginal performance improvements.  

It is quite easy to choke out all user work with system work.  

Resource allocation is not a cookie cutter process once a system’s overall workload becomes a signifigant fraction of system capacity.  

Your mileage will vary.  

mwf  

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Brad Peek (Redacted sender "brad_peek" for DMARC) Sent: Wednesday, December 09, 2020 3:02 PM To: Oracle-l Digest Users
Subject: Fw: Resource Manager Plans and SYSTEM_GROUP    

I joined a team that has several databases with resource manager plans that prioritize SYSTEM_GROUP low relative to some other consumer groups.  

Example:  

GROUP Share

• -----

WEB 60 BATCH 20 SYSTEM_GROUP 10 OTHER_GROUP 10   Since the servers almost never reach 100% CPU it hasn't been a big issue, but I did want to confirm that the general best practice is to give SYSTEM_GROUP the highest priority among the consumer groups.  

I suspect it is a case of copying the same plan across multiple DBs, but before I recommend changing this, can anyone think of a use case where having SYSTEM_GROUP with a relatively low priority would make sense?  

Notes:

• DB version 12.1.0.2
• The mapping for SYSTEM_GROUP is oracle_user in ('SYS', 'SYSTEM')

Brad Peek

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http://www.freelists.org/webpage/oracle-l Received on Wed Dec 09 2020 - 21:46:55 CET