Hello,
SQL> select * from v$sga;

NAME VALUE
-------------------- ---------
Fixed Size 65484
Variable Size 19521536
Database Buffers 16777216
Redo Buffers 73728


In above queries database buffer size comes from db_block_buffers = 8192 # INITIAL parameter of init.ora file. But other parameters like fixed size ,var. size , redo buffers are coming from where ?

How to calculate the memory occupied by an instance ?

Sunil