All Oracle Error Codes
Oracle DBA Forum

Frequent Oracle Errors

TNS:could not resolve the connect identifier specified
Backtrace message unwound by exceptions
invalid identifier
PL/SQL compilation error
internal error
missing expression
table or view does not exist
end-of-file on communication channel
TNS:listener unknown in connect descriptor
insufficient privileges
PL/SQL: numeric or value error string
TNS:protocol adapter error
ORACLE not available
target host or object does not exist
invalid number
unable to allocate string bytes of shared memory
resource busy and acquire with NOWAIT specified
error occurred at recursive SQL level string
ORACLE initialization or shutdown in progress
archiver error. Connect internal only, until freed
snapshot too old
unable to extend temp segment by string in tablespace
Credential retrieval failed
missing or invalid option
invalid username/password; logon denied
unable to create INITIAL extent for segment
out of process memory when trying to allocate string bytes
shared memory realm does not exist
cannot insert NULL
TNS:unable to connect to destination
remote database not found ora-02019
exception encountered: core dump
inconsistent datatypes
no data found
TNS:operation timed out
PL/SQL: could not find program
existing state of packages has been discarded
maximum number of processes exceeded
error signaled in parallel query server
ORACLE instance terminated. Disconnection forced
TNS:packet writer failure
see ORA-12699
missing right parenthesis
name is already used by an existing object
cannot identify/lock data file
invalid file operation
quoted string not properly terminated

Re: CPU priority for AIX 5.3 with mixed workload

Anand Rao



I get a feeling that you might be looking in the wrong direction. If the batch job is not running fast, then you need to look at what the job is doing in the 1st place. as you mentioned, tracing is good idea. so, you've got the answer yourself !

we use a couple of p590 as well as p595 machines with SMT enabled and they are blazing fast. but, i only have 64 cores on the p595 :)

i have tried bumping the priority of Oracle shadow as well as background processes (LGWR, DBWR,etc.) with mixed luck and also depending on whether RAC is used or not.

If you are CPU starved, then you might be better of looking who is chewing up the CPU and why instead of raising the priority, etc. look at profiling your batch job. You mentioned that the batch job completed in 2.5 hours in an identical test system?

was everything identical? the disk setup, Oracle, etc.? you need some detailed data from the test system to compare it to your problematic run. so, statistics collection, tracing is where you might find some clues.

AIX and Tru64 do a fabulous job with process scheduling and priority handling. I never had to touch anything even on the busiest of machines.

hope that helps.


On 06/12/06, Dennis Williams <oracledba.williams@gmail.com> wrote:
Also look at adjusting the nice value.
You should also consider what you will be taking CPU time away from. Usually modern Unix systems do a great job of balancing the requirements of all the users simultaneously. When you start forcing the system to your will, you stand a chance that you may improve the performance of your process, but response could get VERY bad for other users. You may also make things bad for the other users and only help your process slightly.
Consider reading Optimizing Oracle Perfomance by Cary Millsap and Jeff Holt.
Dennis Williams