Oracle Database Administration – Understanding Ten Common ORA Messages

At the old time, the data managers and administrators handling Oracle database systems had to explore many manuals and an unrelenting number of booklets and handouts to figure out the fixes for errors and how to effectively maneuver through the Oracle errors. However, as we can see later, things are mainly changed lately in the search engine era, making the lives of a lot of developers and administrators easier. Now on facing any error or ORA message, you need not have to worry about but can find an appreciable wealth of resources online on the Oracle forums and websites.

Many technology websites out there have dedicated Oracle database writers and bloggers who work for developing content exclusively to streamline the Oracle DBMA handling and troubleshooting for various common and uncommon errors. Rather than browsing through many articles and blogs, we have attempted to equip the users with a custom set of the top ten most searched for Oracle errors and how to deal with the same.

Top 10 ORA messages

1. ORA 00904: Invalid or Nonexistent Column Name

This Is an easy fix. A missing or invalid column name triggers this error. This error can be quickly evaded by ensuring that you begin the column names with a letter and only use numerical value, alphabets, and special characters in it. Using other characters, you may use quotations and do not exceed the length of 30 characters in total.

2. ORA 06512: Unhandled Exceptions in the PLSQL Code

You may not find much info in the description of this OS. It will just be shown as ORA-06512 at a single line. You should learn that s it means the stack is unwound by the unhandled exceptions in the code, which brings forth an error. To manage this, you many correct what is causing this unhandled error, or you may write an exception handler for the error. However, as this is a bit complex scenario, it is advised to refer to the database admin to get more help.

3. ORA 12154: Failed to Connect with the Listener

For this type of error, the query may fail to locate the connecting name in the naming method’s repository. The repository may not be found for many reasons. There are different options available to tackle this error, which primarily involves verification of the file names, syntax, and the net service names.

4. ORA 00942: Executing the nonexistent SQL statement

This ORA message’s root cause is attempting to run an SQL statement that references a view or table that is nonexistent or that which you cannot access. For this, you have to check and see whether the queried table exists, and if it does not exist, then you need to create a specific view or table. If you are nonprivileged to get access to the same, it is advisable to request the administrator about the same and get it done.

5. ORA 01017: Invalid Username or Password

This category of error is a global thing. ORA-01017 means that the either of or both username and password entered by you is incorrect. You have to check the system parameters to ensure that the ID is aimed for the proper location, and then merely re-entering login credentials from the apt location will clear this issue.

6. ORA 00936: Missing Expression

This is yet another syntax fix. This ORA message is triggered from the required clause, which is left out like a SELECT statement that it entered with an incomplete expression or while a reserved word as SELECT TABLE tends to get misused. For better performance tuning of Oracle databases through remote administration, you may contact RemoteDBA.

7. ORA 01722: Invalid Number

This is an error which is popped up due to a failed attempt to convert character stringsto any number. This may happen as the Oracle arithmetic functions may only consist of numbers, and only numerical data can be added or subtracted from the dates. On finding invalid data, which may sometimes be hidden coming as a part of a subquery, you may correct it to fit the numeric parameters of Oracle.

8. ORA 06502: Arithmetic or Numeric Value Error

OR-06502 is an error code triggered when a string, numeric, conversion, arithmetic error, or constraint occurs. It will often result from assigning the value of a numeric variable, which is larger than the given variable permits or by assigning a non-numeric value to the variable, which is numeric only.

9. ORA 00911: Invalid Character

Yet another syntax error that is put as straightforward as possible. This issue’s root cause stems from a series of mistakes like starting an identifier by using any characters other than numbers or letters and not enclosing any identifiers with the special characters in quotes.

10. ORA 00933: Improper Clause for SQL Command

This is the final one in the list of errors we discuss here, which is again a syntax error. This is caused by giving an improper clause that ends in an SQL statement. For example, a given ORDER BY clause may not be used to create an ordered view in the Oracle DB. However, this error may sometimes be triggered when the ORDER BY clause may get attached to the CREATE VIEW statement. It is also a fact that the indented lines additional can also trigger this same problem.

As you know by now, the errors mentioned above are the most search for Oracle ORA errors because these are a bit difficult to resolve. However, on reassuring factor about such Oracle errors is that these mostly derive from simple incompetent syntax mistakes that do not require much knowledge to correct. So anyone who has basic knowledge about this can work with it efficiently. Ensure that you know how to go about it correctly.

As you have seen above, working past these and preventing them may demand a solid understanding of efficiently operating within the Oracle by keeping track of all baseline parameters and the proper action protocols to be followed.