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Home -> Community -> Mailing Lists -> Oracle-L -> Re: log_buffer value does not match spfile value
John,
Do you have 10g Automatic Memory Management (AMM) turned on? If so
then a lot of the init parameters are ignored.
To use AMM you set the sga_max_size, sga_target, and
pga_aggregate_target parameters in the init. The
db_cache_size,db_xk_cache_size, db_keep_cache_size,
db_recycle_cache_size, large_pool_size, log_buffer, shared_pool_size,
java_pool_size, streams_pool_size, sort_area_size, and hash_area_size
become zero, default, or minimum allowing the AMM to increase the size
as needed.
Ron
>>> "Hallas, John, Tech Dev" <John.Hallas_at_gb.vodafone.co.uk> 06/07/06
10:05 AM >>>
I have a number of 10G databases where the value of log_buffer in the spfile is not the same as the value within the instance.
Oracle is obviously deciding it's own value. This is the same on
systems
using ASSM and not (sga_target)
The documentation does not seem to support this but I am sure from a number of instances that this is happening.
Any ideas on this. Nothing much coming from Metalink. I believe that
this is also happening on a databases using an init.ora file rather
than
an spfile
Thanks
John
SQL> show parameter log_buffer
NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ log_buffer integer 2097152
SQL> show parameter spfile
NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ spfile string/WELDBPROD/u01/oradata/GMSDB/s
pfileGMSDB.ora
SQL> !strings /WELDBPROD/u01/oradata/GMSDB/spfileGMSDB.ora | grep -i log_buffer
*.log_buffer=32768
SQL> show parameter sga_target
NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ sga_target big integer 512M
SQL> show sga
Total System Global Area 536870912 bytes
Fixed Size 2030296 bytes Variable Size 234882344 bytes Database Buffers 297795584 bytes Redo Buffers 2162688 bytes
SQL> show parameter shared_pool
NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ shared_pool_reserved_size big integer 11324620 shared_pool_size big integer 0
Manual SGA parameters are specified by the user, and the given sizes precisely control the sizes of their corresponding components.
When SGA_TARGET is set, the total size of manual SGA size parameters
is
subtracted from the SGA_TARGET value, and balance is given to the
auto-tuned SGA components.
For example, if SGA_TARGET = 8G and DB_KEEP_CACHE_SIZE = 1G, this
means
that the total size of the four auto-tuned components (shared pool,
java
pool, default buffer cache, and large pool) is limited to 7GB. The 7GB
includes the fixed SGA and log buffer, and only after those have been
allocated the rest of the memory is divided between the components.
The
size of the keep cache is 1GB, as specified by the parameter.
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-- http://www.freelists.org/webpage/oracle-lReceived on Thu Jun 08 2006 - 13:04:55 CDT
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