Some addition notes:

1. sort_area --> part of PGA not UGA:

SQL> @pga_uga_sesssize

Total Total
PGA MAX UGA MAX
Memory PGA Memory UGA
(bytes) Memory (bytes) (bytes) Memory (bytes)
-------------------- -------------------- -------------------- --------------------
824,852 824,852 173,796 315,916

SQL> alter session set sort_area_size=1000000000;
SQL> @pga_uga_sesssize

Total Total
PGA MAX UGA MAX
Memory PGA Memory UGA
(bytes) Memory (bytes) (bytes) Memory (bytes)
-------------------- -------------------- -------------------- --------------------
824,852 824,852 173,796 315,916
SQL> select 1 from (select 1 from dba_objects order by object_name) where rownum=1;

1
----------
1

SQL> @pga_uga_sesssize

Total Total
PGA MAX UGA MAX
Memory PGA Memory UGA
(bytes) Memory (bytes) (bytes) Memory (bytes)
-------------------- -------------------- -------------------- --------------------
4,506,660 4,506,660 171,420 315,916
Oracle allocate sort area (and hash area too) in PGA, only if this memory need.

2) Where oracle allocate UGA in MTS mode:

if LAGRE_POOL set to 0 (not allocated) then uga allcocate in shared memory.
if LAGRE_POOL set more then 0 then uga allcocate in large pool.
We should be little bit carifull with size of large area in MTS mode.



[Edited by Shestakov on 07-01-2002 at 06:38 PM]