Oracle 10g - Database does not respond to the application users

Question

Hi all,
I am using ORACLE 10g database with 75 users connections 50 local and 20 remote users using ADSL and dial up modem. Operating system on server is
Windows 2003.
All of a sudden users making the entry get disconnected getting the error as
ORA-12516: TNS:listener could not find available handler with matching protocol stack
Other case users when using the appliaction get their PC hanged and connection
to oracle fails again. they cannot login to the application that time, the error is
ORA-04031: unable to allocate %s bytes of shared memory ("%s","%s","%s","%s")
Twice a day the users trying to login cannot access the database server.
Front end application is in VB using exe file. When the users cannot logon
to the database. I manually stop the ORACLE services(including DB console) and
then stop the listener.
This practice is going on since last two months.
Server Scenario
After Installing Oracle Standard Edition 10g.
System tablespace utilization is 98.5% which is 465 MB out of total 470 MB.
There is only one Rollback Segment named as SYSTEM.
when we install 9i 4 rollback segments as RO1, RO2, RO3, RO4 are created
by default.
Do I need to add the datafile to SYSTEM table space as its current usage is 99.15% and its auto extend is ticked on using auto extent as 10 MB. I tried adding another datafile during weekend downtime. when I resumed on saturday morning I found it did not add any datafile which I had put on thursday eveninig as system02.dbf.
Do I need to add a new datafile to the SYSTEM tablespace ?
Do I need to create new rollback segments apart from SYSTEM rollback segment ?
My current schema size 15360Mb with its usage as 9.32% (1432.25 Mb).
Please reply !!!

Answer 1

Hi Paul
My Server configuration is
Compaq ML 370
3.4 Ghz Processor
3.5 GB RAM
SQL> show sga
Total System Global Area 171966464 bytes
Fixed Size 787988 bytes
Variable Size 145488364 bytes
Database Buffers 25165824 bytes
Redo Buffers 524288 bytes
SQL> select * from v$sgastat;
POOL NAME BYTES
fixed_sga 787988
buffer_cache 25165824
log_buffer 524288
shared pool subheap 55600
shared pool KQR L SO 218160
shared pool KQR M PO 1329244
shared pool KQR M SO 605364
shared pool KQR S PO 164156
shared pool KQR S SO 6144
shared pool KTI-UNDO 1235304
shared pool sql area 5368208
shared pool KGLS heap 1597560
shared pool joxs heap 6004
shared pool row cache 3707272
shared pool parameters 17520
shared pool repository 19396
shared pool ASH buffers 4194304
shared pool free memory 16586072
shared pool PL/SQL DIANA 679456
shared pool KSPD key heap 4220
shared pool PL/SQL MPCODE 1167992
shared pool library cache 11368964
shared pool miscellaneous 25942980
shared pool pl/sql source 88
shared pool PLS non-lib hp 29816
shared pool XDB Schema Cac 3594144
shared pool alert threshol 3460
shared pool joxlod exec hp 355820
shared pool table definiti 5880
shared pool temporary tabl 4932
shared pool trigger defini 12848
shared pool trigger inform 1892
shared pool type object de 20256
shared pool private strands 1198080
shared pool event statistics per sess 4384640
shared pool fixed allocation callback 304
large pool free memory 8388608
java pool joxs heap 233856
java pool free memory 44743296
java pool joxlod exec hp 5354496
40 rows selected.
SQL> select segment_name, owner, status
2 from dba_rollback_segs;
SEGMENT_NAME OWNER STATUS
SYSTEM SYS ONLINE
_SYSSMU1$                      PUBLIC ONLINE
_SYSSMU2$                      PUBLIC ONLINE
_SYSSMU3$                      PUBLIC ONLINE
_SYSSMU4$                      PUBLIC ONLINE
_SYSSMU5$                      PUBLIC ONLINE
_SYSSMU6$                      PUBLIC ONLINE
_SYSSMU7$                      PUBLIC ONLINE
_SYSSMU8$                      PUBLIC ONLINE
_SYSSMU9$                      PUBLIC ONLINE
_SYSSMU10$                     PUBLIC ONLINE
SEGMENT_NAME OWNER STATUS
_SYSSMU11$                     PUBLIC ONLINE
_SYSSMU12$                     PUBLIC ONLINE
_SYSSMU13$                     PUBLIC ONLINE
_SYSSMU14$                     PUBLIC ONLINE
_SYSSMU15$                     PUBLIC OFFLINE
_SYSSMU16$                     PUBLIC OFFLINE
_SYSSMU17$                     PUBLIC OFFLINE
_SYSSMU18$                     PUBLIC OFFLINE
_SYSSMU19$                     PUBLIC OFFLINE
_SYSSMU20$                     PUBLIC OFFLINE
_SYSSMU21$                     PUBLIC OFFLINE
SEGMENT_NAME OWNER STATUS
_SYSSMU22$                     PUBLIC OFFLINE
_SYSSMU23$                     PUBLIC OFFLINE
_SYSSMU24$                     PUBLIC OFFLINE
_SYSSMU25$                     PUBLIC OFFLINE
_SYSSMU26$                     PUBLIC OFFLINE
27 rows selected.
Currently AUTOEXTEND is ticked as on for SYSTEM tablespace and its size is showing as 99.16% (466.06 mb) used which is very much nearing to its full capacity of 470 mb.
Currently 75 users - 50 Local users and 20 Remote Users are connected to the server. Is there any limit that Server should have limited connections.
Server has Windows 2003 Standard Edition. Has Windows 2003 anything to do
with the no. of users getting connected ?