Here let us see some important Oracle error codes -
1) ORA-00001: unique constraint (constraint_name) violated
Cause -
You tried to execute an INSERT or UPDATE statement that has created a duplicate value in a field restricted by a unique index.
Option #1 Drop the unique constraint.
Option #2 Change the constraint to allow duplicate values.
Option #3 Modify your SQL so that a duplicate value is not created.
2) ORA-00051: time-out occurred while waiting for resource
Cause -
You were waiting for a resource and you timed out. This may have been caused by an Oracle instance abnormally terminating.
Option #1 Restart the Oracle instance.
3) ORA-00068: invalid value num for parameter num, must be between num and num
Cause -
The value for the initialization parameter must be between the numbers specified in this error message.
Option #1 Update the initialization parameter accordingly.
4) ORA-00257: archiver is stuck. CONNECT INTERNAL only, until freed
Cause -
While trying to archive a redo log file, the ARCH process encountered an error.
Option #1 This error can be caused when the destination device does not have enough storage space to store the redo log file.
Option #2 Check that the initialization parameter ARCHIVE_LOG_DEST in the initialization file is set correctly.
5) ORA-00018: maximum number of sessions exceeded
Cause -
You tried to execute a statement that requested a resource. Since the maximum number of sessions have been reached, Oracle will not process any new resource requests.
Option #1 You can wait a few minutes and try to re-execute the statement(s).
Option #2 You can shut down Oracle, increase the SESSIONS parameter in the initialization parameter file, and restart Oracle.
6) ORA-00054: resource busy and acquire with NOWAIT specified
Cause -
You tried to execute a LOCK TABLE or select or update command with the NOWAIT keyword but the resource was unavailable.
Or you tried to DROP a COLUMN using the ALTER TABLE command and received the error.
Option #1 Wait and try the command again after a few minutes.
Option #2 Execute the command without the NOWAIT keyword.
Option #3 If the error occurred while trying to DROP a COLUMN, be sure to backup the data. Then TRUNCATE the table and execute the DROP COLUMN command again
7) ORA-00071: process number must be between 1 and num
Cause -
You tried to specify a process number that was not valid.
Option #1 Specify a process number that is between 1 and the number listed in the error message.
8) ORA-00301: error in adding log file <name> - file cannot be created
Cause -
You tried to create a redo log file, but the creation failed.
Option #1 Check if there is enough storage space on the device.
Option #2 Check if the device is available.
Option #3 Check if the file name is correct.
9) ORA-00020: maximum number of processes num exceeded
Cause -
You tried to execute a statement that requested a resource. Since the maximum number of processes have been reached, Oracle will not process any new requests.
Option #1 You can wait a few minutes and try to re-execute the statement(s).
Option #2 You can shut down Oracle, increase the PROCESSES parameter in the initialization parameter file, and restart Oracle.
10) ORA-00057: maximum number of temporary table locks exceeded
Cause -
The number of temporary tables has reached or exceeded the number of temporary table locks allowed by Oracle.
Option #1 This error is most commonly caused by a SQL statement that has performed a very large sort. The sort has created a number of temporary tables that has exceeded the limit specified in Oracle.
To correct this problem, increase the TEMPORARY_TABLE_LOCKS parameter in Oracle and perform a restart in Oracle.
11) ORA-00078: cannot dump variables by name
Cause -
You tried to dump a variable by name, but your system does not support this option.
Option #1 Try the PEEK command.
12) ORA-00304: requested INSTANCE_NUMBER is busy
Cause -
You tried to start an Oracle instance by using an INSTANCE_NUMBER parameter value that is already in use.
Option #1 Modify the INSTANCE_NUMBER initialization parameter in the initialization file to use another number. Then try restarting the instance.
Option #2 Wait for recovery to finish for that instance number.
13) ORA-00023: session references process' private memory; cannot detach session
Cause -
You tried to detach a session but it contains references to the process memory (PGA) through any of: an open network connection, a very large context area, or operating system privileges.
Option #1 If the session has an open network connection or a very large context area, you can try closing the session's database links and cursors.
Option #2 If the session has operating system privileges, you will not be able to detach the session.
14) ORA-00058: DB_BLOCK_SIZE must be num to mount this database not num
Cause -
You tried to start a database whose DB_BLOCK_SIZE parameter value in the initialization file does not match the value used when the database was created.
Option #1 Make sure that you are mounting the correct database.
Option #2 Make sure that you are using the correct initialization file.
Option #3 You may need to change the DB_BLOCK_SIZE parameter in the initialization file.
15) ORA-00100: no data found
Cause -
An application tried to access data that was either inaccessible or does not exist.
Option #1 This error must be handled within the application. Modify the application accordingly.
16) ORA-00361: cannot remove last log member name group num
Cause -
You tried to remove the last member of a redo log group.
Option #1 You can try deleting the log using the DROP log file command.
17) ORA-00028: your session has been killed
Cause -
Your session has been killed by a privileged user (such as a DBA).
Option #1 Check with your DBA. Your session may have been killed due to a scheduled outage or other activity
18) ORA-00060: deadlock detected while waiting for resource
Cause -
You tried to execute a statement, but your session was deadlocked because another session had the same resource locked. The statement(s) that you tried to execute have been rolled back.
Option #1 You can wait a few minutes and try to re-execute the statement(s) that were rolled back.
Option #2 You can execute a ROLLBACK and re-execute all statements since the last COMMIT was executed.
19) ORA-00107: failed to connect to network listener process
Cause -
The network listener process was not been successfully started.
Option #1 Make sure that the network configuration file is set up correctly.
Option #2 Make sure that the client-side address is set up correctly.
Option #3 Make sure that the listener initialization parameter file is set up correctly.
20) ORA-00401: the value for parameter name is not supported by this release
Cause -
You tried to specify a value in the initialization file that is not supported by this release of Oracle
Option #1 You need to enter a value that is supported by your version of Oracle, or remove the parameter value from the initialization file so that the default value is used.
21) ORA-00034: cannot COMMIT or ROLLBACK in current PL/SQL session
Cause -
You tried to issue a COMMIT or ROLLBACK command from a PLSQL function, procedure, or package. However, COMMIT and ROLLBACK have been disabled with the following command:
Alter SESSION Disable COMMIT IN PROCEDURE;
Option #1 Do not issue a COMMIT or ROLLBACK command from your PLSQL function, procedure, or package while disabled.
Option #2 Enable COMMIT or ROLLBACK for this PLSQL session.
22) ORA-00063: LOG_FILES initialization parameter exceeded
Cause -
The value of the LOG_FILES parameter must be as large as the highest number log that exists.
Option #1 Increase the LOG_FILES parameter value in the initialization file and then perform an Oracle warm start.
23) ORA-00201: control file version num incompatible with Oracle version num
Cause -
The control file was created by a version of Oracle that is different than the version of Oracle that you are currently running.
Option #1 Restart Oracle with a version of Oracle that is the same as the control file.
Option #2 Create a new control file using the CREATE CONTROLFILE command.
24) ORA-00900: invalid SQL statement
Cause -
The statement that you've tried to execute is not a valid SQL statement.
25) ORA-00902: invalid datatype
Cause -
You tried to execute a CREATE TABLE or ALTER TABLE statement that contained an invalid datatype.
26) ORA-00903: invalid table name
Cause -
You tried to execute a SQL statement that included an invalid table name or the table name does not exist.
27) ORA-00904: invalid identifier
Cause -
You tried to execute a SQL statement that included an invalid column name or the column name is missing. This commonly occurs when you reference an invalid alias in a SELECT statement.
28) ORA-00905: missing keyword
You tried to execute a statement, but you missed a required keyword.
29) ORA-00906: missing left parenthesis
You tried to execute a statement, but you missed entering a required left parenthesis.
30) ORA-00907: missing right parenthesis
You entered a left parenthesis, but missed the closing right parenthesis; or you entered invalid data within the parentheses.
All parentheses must be entered in pairs.
31) ORA-00908: missing NULL keyword
You tried to execute a SQL statement, but you missed entering the NULL keyword
This error can occur if you try to execute a SQL statement using the IS NULL condition or IS NOT NULL condition, but miss entering the NULL keyword.
32) ORA-00909: invalid number of arguments
You tried to call an Oracle function, but you used the incorrect number of arguments for the function.
33) ORA-00910: specified length too long for its datatype
You tried to create a VARCHAR2 or CHAR column, but you specified a length that exceeded Oracle's limits.
Enter a maximum length for the VARCHAR2 or CHAR column that falls within Oracle's limits.
34) ORA-00911: invalid character
You tried to execute a SQL statement that included a special character.
Option #1 This error occurs when you try to use a special character in a SQL statement. If a special character other than $, _, and # is used in the name of a column or table, the name must be enclosed in double quotations.
Option #2 This error may occur if you've pasted your SQL into your editor from another program. Sometimes there are non-printable characters that may be present. In this case, you should try retyping your SQL statement and then re-execute it.
Option #3 This error occurs when a special character is used in a SQL WHERE clause and the value is not enclosed in single quotations.
35) ORA-00913: too many values
You tried to execute a SQL statement that required two sets of equal values, but you entered more items in the second set than was in the first set.
Option #1 This error often occurs when you are performing a INSERT statement and enter more values in the VALUES clause than the number of columns that you listed.
Option #2 This error can also occur when your subquery in the WHERE clause returns too many columns.
36) ORA-00917: missing comma
You tried to execute a statement, but you missed a required comma.
37) ORA-00918: column ambiguously defined
You tried to execute a SQL statement that joined two or more tables, where a column with the same name exists in both tables.
Prefix the column with the table name and then re-execute the statement.
38) ORA-00919: invalid function
You tried to call a function, but the name you used was not a valid Oracle function.
Correct the spelling of the Oracle function that you wish to call.
OR
Try using the dual table if you wish to call a function without querying a table.
39) ORA-00920: invalid relational operator
You tried to execute a SQL statement, but the WHERE clause contained an invalid relational operator.
40) ORA-00920: invalid relational operator
You tried to execute a SQL statement, but the WHERE clause contained an invalid relational operator.
Correct the WHERE clause. Valid relational operators are as follows:
= != ^= <> < <=
> >= ALL ANY
BETWEEN NOT BETWEEN EXISTS NOT EXISTS
IN NOT IN IS NULL IS NOT NULL
LIKE NOT LIKE
41) ORA-00923: FROM keyword not found where expected
You tried to execute a SELECT statement, and you either missed or misplaced the FROM keyword
42) ORA-00924: missing BY keyword
You tried to execute a GROUP BY, ORDER BY, CONNECT BY, or GRANT (with IDENTIFIED) statement and missed the BY keyword.
43) ORA-00925: missing INTO keyword
You tried to execute a INSERT statement and missed the INTO keyword.
44) ORA-00926: missing VALUES keyword
You tried to execute an INSERT statement and missed the VALUES keyword.
45) ORA-00927: missing equal sign
You tried to execute a statement, but missed an equal sign. This can happen in either the SET clause of a UPDATE statement or in a search condition.
46) ORA-00928: missing SELECT keyword
Probably tried to create an Oracle VIEW, but missed the SELECT keyword.
47) ORA-00929: missing period
This is an internal error message. (Contact customer support.)
48) ORA-00930: missing asterisk
This is an internal error message. (Contact customer support.)
49) ORA-00931: missing identifier
This is an internal error message. (Contact customer support.)
50) ORA-00932: inconsistent datatypes
Tried to perform an operation between two different datatypes, but the datatypes are not compatible.
51) ORA-00933: SQL command not properly ended
Probably tried to execute a SQL statement with an inappropriate clause.
52) ORA-00934: group function is not allowed here
Probably tried to execute a SQL statement that included one of the group functions (ie: MIN Function, MAX Function, SUM Function, COUNT Function) in either the WHERE clause or the GROUP BY clause
53) ORA-00935: group function is nested too deeply
This is an internal error message. (Contact customer support.)
54) ORA-00936: missing expression
Probably tried to execute a SQL statement but you omitted a part of the syntax. For e.g.
Select from employee;
55) ORA-00937: not a single-group group function
Probably tried to execute a SELECT statement that included a GROUP BY function (ie: MIN Function, MAX Function, SUM Function, COUNT Function), but was missing the GROUP BY clause.