create pfile='/u01/app/oracle/product/10.2.0/db_1/dbs/init_my.ora' from spfile='/u01/app/oracle/product/10.2.0/db_1/dbs/spfileorcl.ora';
startup pfile='/u01/app/oracle/product/10.2.0/db_1/dbs/init_my.ora' MOUNT
create spfile from pfile='/u01/app/oracle/product/10.2.0/db_1/dbs/init_my.ora';
-- XE path
-- /usr/lib/oracle/xe/app/oracle/product/10.2.0/server/dbs/
startup pfile='/u01/app/oracle/product/10.2.0/db_1/dbs/initpf.ora';
ALTER SYSTEM SET DB_CREATE_ONLINE_LOG_DEST_4='/u02/oracle/oradata/pftest' SCOPE=SPFILE;
select * from v$SGASTAT;
show parameter shared_pool_size;
select sum(bytes) from v$sgastat where pool='shared pool';
select pool,name,bytes from v$sgastat where name='free memory' and pool='shared pool';
show sga;
show parameter sga_max_size
show parameter shared_pool_size;
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:1513005503967