SGA memory structure

show parameter sga_

NAME                                 TYPE        VALUE
------------------------------------ ----------- -------
sga_max_size                         big integer 280M
sga_target                           big integer 280M



SQL> select name,bytes/1024/1024 "Mbs" from v$sgainfo;

NAME                                    Mbs
-------------------------------- ----------

Fixed SGA Size                   1.19078064
Redo Buffers                     2.80859375
Buffer Cache Size                       196
Shared Pool Size                         68
Large Pool Size                           4
Java Pool Size                            4
Streams Pool Size                         4
Granule Size                              4
Maximum SGA Size                        280
Startup overhead in Shared Pool          36
Free SGA Memory Available                 0


============================================================
============================================================
Buffer Cache Size                       196
Shared Pool Size                         68
Large Pool Size                           4
Java Pool Size                            4
Streams Pool Size                         4
Granule Size                              4
----------------------------------------------------
Maximum SGA Size                        280



SQL> show sga

Total System Global Area  293601280 bytes   280   Mbs
Fixed Size                  1248624 bytes   1.190 Mbs
Variable Size              83886736 bytes   80    Mbs
Database Buffers          205520896 bytes   196   Mbs       
Redo Buffers                2945024 bytes   2.808 Mbs


Database buffers(196)=Buffer Cache Size (196)

Variable Size(80)=Shared Pool Size(68) + Large Pool Size(4) + Java Pool Size(4) + Streams Pool Size(4)


select name,bytes/1024/1024 "mbs" from v$sgainfo where name like '%Pool%' or name like '%Buffer%';