cancel
Showing results for 
Search instead for 
Did you mean: 

Oracle memory Managment

George Nikoloudis_1
Frequent Advisor

Oracle memory Managment

Hi,

I would like to ask except the SGA is oracle reserves other memory for sessions or any other reason?
6 REPLIES
Jean-Luc Oudart
Honored Contributor

Re: Oracle memory Managment

Hi George,

I suppose you have access to Metalink.

You can starts with the following documents :
[NOTE:148346.1] Monitoring Automated SQL Execution Memory Management
[NOTE:223730.1] Automatic PGA Memory Management in 9i
Note:147806.1 -- Oracle9i New Features: Automated SQL Execution Memory Management


Regards,
Jean-Luc
fiat lux
Steve Steel
Honored Contributor

Re: Oracle memory Managment

Hi

See
http://www.oracle-training.cc/teas_elite_troub_3.htm

Then add on the memory each process needs just to exist at system level

The SGA is just a big parcel service sending parcels of data between back and front line processes


Steve Steel
If you want truly to understand something, try to change it. (Kurt Lewin)
Andreas D. Skjervold
Honored Contributor

Re: Oracle memory Managment

Hi

Oracle creates a PGA area in memory for each dedicated connection to the database.
If you set up the database with Multi Threaded Server option, some of the PGA data is moved inside the SGA and thus reduce your memory needs for multiple connections.

rgds
Andreas
Only by ignoring what everyone think is important, can you be aware of what everyone ignores!
Brian Crabtree
Honored Contributor

Re: Oracle memory Managment

George,

The primary cost for each sessions connection to the database is the 'sort_area_size' and 'sort_area_reserved_size'. There is some other cost associated with the PGA, but it shouldn't be very high. These will be the major portion.

Thanks,

Brian
George Nikoloudis_1
Frequent Advisor

Re: Oracle memory Managment

I have sessions with more than 100M Resources allocated. I am sending to you also the file with this processes.

I have about 150 of such process.
Brian Crabtree
Honored Contributor

Re: Oracle memory Managment

George,

I wouldn't worry about the setting from the 'ps' command, as this will show memory that is being taken up from the shared memory of the database as well. So the amount of from Oracle processes shown can well exceed the amount of memory taken or available on the system. I would suggest using 'glance' to check for memory management, and tune from there.

If you are worried, please put your init.ora out, along with the amount of memory on your system, whether this is only a DB server, or if you application runs on it, and how many databases exist on the system.

Otherwise, I wouldn't worry. You most likely are ok.

Thanks,

Brian