PGA target sizing problems

Question

Hi,
there is somithing strange at mt pga size,
when im quering the select from v$parameter where name like '%pga%'*
it results that the size is 2528M
but when i SELECT FROM V$PGASTAT;* the aggregate PGA target parameter value is *23552M*
aggregate PGA target parameter     24696061952*
aggregate PGA auto target     22027751424*
global memory bound     1073741824*
total PGA inuse     264313856*
total PGA allocated     549178368*
maximum PGA allocated     11695941632*
total freeable PGA memory     152305664*
process count     112*
max processes count     151*
PGA memory freed back to OS     1762389131264*
total PGA used for auto workareas     42818560*
maximum PGA used for auto workareas     8992131072*
total PGA used for manual workareas     0*
maximum PGA used for manual workareas     10506240*
over allocation count     0*
bytes processed     251448016746496*
extra bytes read/written     832811437056*
cache hit percentage     99.66*
recompute count (total)     927028*
i changed the pga_aggregate_target using alter system ... scope=both; but nothing changed.
what can be the problem?? is there anything like flush pga?
My oracle version:
Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production
PL/SQL Release 11.1.0.7.0 - Production
"CORE     11.1.0.7.0     Production"
TNS for Linux: Version 11.1.0.7.0 - Production
NLSRTL Version 11.1.0.7.0 - Production
memory_max_target=55G
memory_target=45G
sga_target=0
sga_max_size=55G
pga_aggregate_target=2528M

Answer 1

Hi,
Refer to the follow link:
http://www.oracle-base.com/articles/11g/AutomaticMemoryManagement_11gR1.php
The SGA and PGA parameters will thus act as minimum buffer sizes within AMM (same as db_buffer_cache, shared_pool_size, large_pool_size and java_pool_size in 10g with ASMM).
Regards,
Thierry
Edited by: Urgent-IT on Jan 10, 2011 1:16 PM