Not able to get Shared Server Mode to work in XE

Question

The server is an HP Dual CPU Xeon, 4 GB RAM. 120GB HD.
Oracle XE reports the following:
SGA 768 Target, 768MB Current.
PGA 256MB Target, 55MB current (when there are a small number of client connections)
The application and database work properly with a small number of connections, but
memory usage goes way up on PGA when I start to add more connections.
I have tried to set up the Oracle server in "Shared Server Mode" , but it appears
that I was unsuccessful.
From what I can tell, the oracle listener does not seem to be fowarding the incoming requests to the shared server dispatchers, but
instead it is deciding to kick off a dedicated server process to handle each client request.
In other words, it is working in dedicated server mode.
I am stumped as to what needs to be done next. From what
I can tell from reading documentation this should be working.
Please advice as to what else I can do to get things working.
Here is additional information:
The parameter SHARED_SERVERS is equal to 4.
parameter dispatchers=(PROTOCOL=TCP) (SERVICE=XEXDB)
max_shared_servers, max_dispatchers, shared_server_sessions have no values.
processes=150
sessions=170
Output of lnsrctl utility:
LSNRCTL> services
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0
LOCAL SERVER
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0
LOCAL SERVER
Service "XEXDB" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Handler(s):
"D000" established:0 refused:0 current:0 max:1002 state:ready
DISPATCHER <machine: CO_DB, pid: 5844>
(ADDRESS=(PROTOCOL=tcp)(HOST=myhostname)(PORT=1771)
Service "XE_XPT" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
Service "xe" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
The command completed successfully
ILSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
STATUS of the LISTENER
Alias LISTENER
Version TNSLSNR for 32-bit Windows: Version 10.2.0.1.0 - Produ
ction
Start Date 18-SEP-2007 16:06:55
Uptime 0 days 0 hr. 1 min. 33 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Default Service XE
Listener Parameter File E:\oraclexe\app\oracle\product\10.2.0\server\network\a
dmin\listener.ora
Listener Log File E:\oraclexe\app\oracle\product\10.2.0\server\network\l
og\listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC_FOR_XEipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=myhostname)(PORT
=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=8080))(Presentation=
HTTP)(Session=RAW))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Service "XE_XPT" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Service "xe" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
The command completed successfully
The contents of the spfile2init.ora file:
xe.__db_cache_size=104857600
xe.__java_pool_size=4194304
xe.__large_pool_size=469762048
xe.__shared_pool_size=222298112
xe.__streams_pool_size=0
*.audit_file_dest='E:\oraclexe\app\oracle\admin\XE\adump'
*.background_dump_dest='E:\oraclexe\app\oracle\admin\XE\bdump'
*.compatible='10.2.0.1.0'
*.control_files='E:\oraclexe\oradata\XE\control.dbf'
*.core_dump_dest='E:\oraclexe\app\oracle\admin\XE\cdump'
*.db_name='XE'
*.db_recovery_file_dest='f:\oracle_flash_recovery_area'
*.db_recovery_file_dest_size=42949672960
*.dispatchers='(PROTOCOL=TCP) (SERVICE=XEXDB)'
*.job_queue_processes=4
*.open_cursors=300
*.os_authent_prefix=''
*.pga_aggregate_target=268435456
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sessions=20
*.sga_target=805306368
*.shared_servers=4
*.undo_management='AUTO'
*.undo_tablespace='UNDO'
*.user_dump_dest='E:\oraclexe\app\oracle\admin\XE\udump'
The contents of listener.ora:
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = E:\oraclexe\app\oracle\product\10.2.0\server)
(PROGRAM = extproc)
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = E:\oraclexe\app\oracle\product\10.2.0\server)
(PROGRAM = extproc)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
(ADDRESS = (PROTOCOL = TCP)(HOST = myhostname)(PORT = 1521))
DEFAULT_SERVICE_LISTENER = (XE)
The contents of tnsnames.ora
XE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = myhostname)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XE)
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
ORACLR_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
(CONNECT_DATA =
(SID = CLRExtProc)
(PRESENTATION = RO)
The contents of sqlnet.ora:
# This file is actually generated by netca. But if customers choose to
# install "Software Only", this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.
SQLNET.AUTHENTICATION_SERVICES = (NTS)

Answer 1

I don't think it is supported because of XE multiple cpu usage limitations but "shared server" is not documented in the XE documentation - http://www.oracle.com/pls/xe102/ranked?word=%22shared+server%22
so you may want to follow this guide for setup and try -
http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/manproc.htm#ADMIN00502
Best Regards,
H.Tonguç YILMAZ
My Oracle blog
http://tonguc.wordpress.com
"Never believe all you read or hear! Just because it is printed or someone is more experienced doesn't mean it is TRUE.."