All Oracle Error Codes
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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


Niall Litchfield


On Tue, 24 Aug 2004 11:29:33 +0300, sjhussain@(protected)
> Gents,
> I was just read Oracle Metalink Note 223730.1 Automatic PGA Memory
> Management in 9i. There is a recommended formula for setting PGA on OLTP
> and DSS systems. I am interested in OLT system only.
> For OLTP the folurma is PGA_AGGREGATE_TARGET = (<Total Physical Memory> *
> 80%) * 20%
> I just want to ask you people, how accurate is this formula?

It isn't 'accurate' it is a way of picking a starting value for P_A_T,
It seems perfectly adequate for this purpose. The meat of the note is
in stage 2 where it gives you some steps for monitoring the behaviour
of your system and adjusting the value accordingly, as well as details
of what P_A_T is actually doing.

For what its worth it seems to me that the first assumption (that only
80% of the system memory is available to Oracle ) seems fine. The
second part, that you should allocate 20% of what is available to PGA
(and presumably 80% to SGA ) for OLTP and make the split 50/50 for DW
seems entirely arbitrary.

The unstated assumption I suppose behind all of it is that the total
physical memory available is sized in some intelligent way.
Niall Litchfield
Oracle DBA
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