This is not a joke.....!!! 

This is from a business critical production database that I was asked to
'review' past Friday. 

The report is from v$system_event taken at 10:30am, Aug 9, 2002. 
The server (and database) was bounced on Aug 4, 2002 at 9:20am.

This was the 1st time I was logging into this database. 

SQL> /

EVENT                               TOTAL_WAITS TOTAL_TIMEOUTS TIME_WAITED
AVERAGE_WAIT                                             
----------------------------------- ----------- -------------- -----------
------------                                             
control file parallel write              143933              0  4080356626
28349.0001                                             
db file scattered read                 12540695              0  1.2254E+10
977.107332                                             
buffer busy waits                      10740450             36  8193235928
762.839167                                             
SQL*Net message from client           180769027              0  9.9561E+10
550.761199                                             
db file sequential read               298968127              0  1.1839E+11
395.99129                                             
enqueue                                   13500           6435     2036785
150.872963                                             
SQL*Net more data from client          52227948              0  4093231165
78.3724294                                             
free buffer waits                            16              4         795
49.6875                                             
log file switch completion                  804             43       16263
20.2276119                                             
log buffer space                            977              0        5409
5.53633572                                             
control file single write                    17              0          51
3                                             
db file parallel write                  1749695              0     2935317
1.67761638                                             
db file parallel read                      8149              0       13484
1.65468156                                             
log file single write                      1024              0         701
.684570313                                             
latch free                              2007034        1616763     1054137
.525221297                                             
log file sync                           1366242            560      526049
.385033545                                             
SQL*Net message from dblink             1514480              0      451351
.298023744                                             
log file sequential read                 405415              0       82877
.204425095                                             
SQL*Net break/reset to dblink                10              0           2
.2                                             
log file parallel write                 2025192              7      293332
.144841576                                             
SQL*Net break/reset to client             28113              0        3221
.114573329                                             
db file single write                        320              0          36
.1125                                             
SQL*Net more data from dblink            447044              0       11375
.025444923                                             
SQL*Net more data to client            11770996              0       75680
.006429362                                             
control file sequential read             554851              0        3261
.005877254                                             
SQL*Net more data to dblink                1076              0           5
.00464684                                             
buffer deadlock                            1045           1029           1
.000956938                                             
SQL*Net message to dblink               1514485              0         456
.000301092                                             
SQL*Net message to client             180769119              0       48736
.000269604                                             

29 rows selected.

SQL> 

Here is the environment: 
1)all the file systems for the database, including dump directories are in a
single disk volume group, 2) all redo logs and control files are spread
among all the other database files, 3) Hitachi array is in use with nothing
but RAID-5 for all files (redo as well), 4) the real hard drives within the
array are either shared with other databases on the same server or with
other servers, 5) redo logs are of 100MB size and switch 20+ times/hour when
some of the batch processes run in the evening, 6) no changes are allowed to
any SQL code, Pro*COBOL code that use 'COPYBOOKs' (Remember those?) to
interact with tables at single row level (no array processing) using
routines with bunch of parameters (call insert... call update... call
delete...), 7) the array has 32GB of NV cache and that's the max it can have
(the DB is 180GB, there are 3 other similar ones from just this server).  

Now the 'icing on the cake': 
 The server has 3 other critical databases. All 4 running in archive log
mode. All share the *same* archive log destination. And all databases are
expected to have same amount of batch processing. The archive log
destination is 8GB in size on the 2nd VG. The DB in question, generated
1.8GB to 2+GB of logs in less than an hour during batch processing. At times
our automated archived log siphoning process encounters some bottlenecks
from our single IBM/Tivoli TSM Server where the logs are deposited before
those are purged from archive log destination...

I was also informed that I will not have much chance to bring about any
changes in the environment described above. Because, I was told, ...it is
the corporate decision to use RAID-5 with HDS array and it is 'the most cost
effective way to address our storage needs'.... and a single VG per database
helps UNIX support to implement HACMP with much ease... and we can not meet
our published deadlines if we made any changes and spent time in testing
those unscheduled changes...... yadi yadi yada.... 


- Kirti 
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Deshpande, Kirti
  INET: [EMAIL PROTECTED]

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