Guides to re-allcoate SGA:
1. shutdown immediate all oracle instances.
2. backup files:
cd $ORACLE_HOME/lib
cp -a libserver9.a libserver9.a.org(backup liberver9.a)
cd $ORACLE_HOME/bin
cp -a oracle oracle.org(backup oracle)
3. Generete new SGA mapped base:cp -a libserver9.a libserver9.a.org(backup liberver9.a)
cd $ORACLE_HOME/bin
cp -a oracle oracle.org(backup oracle)
cd $ORACLE_HOME/rdbms/lib
cp ksms.s ksms.s.org ;
cp ksms.o ksms.o.org;
genksms -s 0x12000000 > ksms.s
--- Size of 0x12000000 is 300 M. (Refering to PS)
4. generate new ksms file
make -f ins_rdbms.mk ksms.o
5. re-compile
make -f ins_rdbms.mk ioracle
Now the Oracle database server is modified to support SGA more than 1.7 G size, then you can update db_cache_size or db_block_buffers to increase data buffers.
ps:
select to_number('12000000','xxxxxxxxxxxxxxx') from dual;
TO_NUMBER('12000000','XXXXXXXX
------------------------------
301989888