Oracle SGA Real Time Consumption Information(9i,10g and 11g)

Question

Hello,
I need to prepare a comparative analysis report of SGA for an Oracle Production Instance
The analysis would show the pre-allocated memory to SGA components v/s real time consumption of memory by these SGA components. I need to do this for each of following components.
SGA itself
Fixed Size
Variable Size
Database Buffers
Redo Buffers
The pre-allocated memory to above SGA components can be obtained by querying v$sga. But from where do I get its real time(current) memory conusmption in Oracle Production environment.
In addition to above, i need the same information (pre-allocated and real time consumption) for following.
Keep buffer cache
Recycle buffer cache
Specific block size caches
Shared pool
Large pool
Java pool
streams pool
Which tables do I need to consider in order to derive 1)pre-allocated memory and 2)real time consumption for above mentioned SGA components
Please advice.
Thank you for your time in reading this post.
Thanks,
Ruchir

Answer 1

Hi,
Have a look at v$sgastat. Also, use statspack in 9i and AWR reports on 10g. Also, the size of the caches won't grow unless they are used. The parameters you have specified within the parameter file, like sga_target (10g onwards) and possibly the other pools if you have specified them, will show you what the caches can grow to.
For example, you could just log onto the DB and do show parameter sga_ or shared_pool and you will seee values for these. Also, it depends whether you are running in automatic memory management mode - where the sga_target parameter is set - or manual. 9i will be manual, but 10g could be auto. In manual case, 9i, check out the parameters individually.
Also, read the docs about the parameters shown and you will see what it says abotu them. There will be lots in the docs about performance tuning and monitoring of the instance. You might even learn some other interesting facts while reading through the docs...
Hope this helps,
Rob
http://www.ora00600.com