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

8.1.7 connection problems

Stephan Eichenlaub



every once in a while (maybe once in two months) a customer has
connection problems to his production database.

Version is 8.1.7. Setup is a database server (linux) and a windows
server that runs the application (and several clients connecting to the
application but that's of no importance here).

The connection failure only seems to occur at night. After maintenance
the database is started up again, then has about 30 minutes of idle
time, gets a tnsping 10 to wake up the connection - and right after the
tnsping sqlplus gets an error.
In the batch these commands are issued right after another:

------------- start here ------------
tnsping mySID 10  >> mylog
sqlplus -s system/password@(protected)
------------- end here -------------

The result usually is that things work like intended but sometimes it
doesn't. The logfile mylog shows:

------------- start here ------------

TNS Ping Utility for 32-bit Windows: Version - Production on
25-OKT-2005 22:00:00

(c) Copyright 1997 Oracle Corporation. All rights reserved.

Attempting to contact
OK (40 msec)
OK (40 msec)
OK (0 msec)
OK (0 msec)
OK (0 msec)
OK (0 msec)
OK (0 msec)
OK (0 msec)
OK (0 msec)
OK (0 msec)
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux Error: 2: No such file or directory

------------------ end here -------------

The tnsping seems to have helped making the connection error happen less
often - but apparently it's not the solution to the problem as in the
example above it reports 10 fine pings - and right after that the
connection can't be established.

What could be the reason, where would you start looking?
In the oracle logfiles on the database server nothing shows up, not even
a connection attempt.
Strangely enough, I haven't found a recent sqlnet.log on the machine
that runs the script.

Stephan Eichenlaub

Stephan Eichenlaub                         xx49-261-9141500
St.-Josef-Platz 10                         xx49-162-9068888
D-56068 Koblenz                     http://www.eichenlaub.net