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: Something easy? ORA-01450: maximum key length (6398) exceeded

Tanel Poder


> If you define CLASS VARCHAR2(2000 CHAR) then you can insert 4000 chars
> irrespective of their single- or multi- bytes.

Yep, when your NLS_LENGTH_SEMANTICS is set to CHAR (or you specify it at the
table column level) the behavior is same, but nevertheless the settings,
there are hard limits of 2000 BYTES for CHAR and 4000 BYTES for VARCHAR2.
You can't exceed those.

And beware the varchar2 case (tested on

SQL> create table t(a varchar2(4000 char));

Table created.

SQL> insert into t values(rpad('?',4000,'?'));

1 row created.

SQL> select length(a) from t;


The input is silently truncated!
Char case is better, it gives an error on overflow:

SQL> insert into t values(rpad('?',2000,'?'));
insert into t values(rpad('?',2000,'?'))
ERROR at line 1:
ORA-12899: value too large for column "SYS"."T"."A" (actual: 4000, maximum:

The index creation error was probably because the AL32UTF8 encoding was
used. With AL32UTF8, Oracle has to count for max 4 bytes per character, thus
couldn't allow creation of this index. If you either use UTF8 encoding (max
3 bytes per char) or just set NLS_LENGTH_SEMANTICS to BYTE before creating
the tables.