Altering SGA size

Hi,
We are in the process to increase the size of SGA to improve the performance of our Production Database, as its performance have been degraded.
Our database server is having total 2GB of RAM.
SGA_MAX_SIZE is not defined in the init.ora file
The following are the details of database memory structures :
Total System Global Area = 180.63088 (MB)
database buffers = 53.4921875 (MB)
shared_pool_size = 100 (MB)
large_pool_size = 0.5859 (MB)
java_pool_size = 20 (MB)
db_block_buffers = 6847 bytes
db_block_size = 8192 bytes
So how much SGA size can we increase to improve the performance of the database server?
which parameters from above are required to be altered and upto how much size ?
Kind request to provide the guidance.
Regards.

hi
this depends upon organization to organization
well just check this out the link
http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/create.htm#ADMIN00207
Hope this helps
CHeers

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