Diagnosing and Fixing the ORA-01638 Error in Oracle

If you are encountering the ORA-01638 error in Oracle, it means that you have specified an invalid value for the MAXDATAFILES parameter in your database. This error can occur when creating a new tablespace or altering an existing one. In this article, we will discuss how to diagnose and fix this error, as well as provide multiple examples and sample code to cover all possibilities.

Diagnosing the ORA-01638 Error

When you encounter the ORA-01638 error, the first step is to check the value you have specified for the MAXDATAFILES parameter. This parameter specifies the maximum number of data files that can be associated with a tablespace. If the value you have specified is not within the valid range, you will encounter this error.

To diagnose the error, you can run the following query in SQL*Plus or SQL Developer to check the current value of the MAXDATAFILES parameter for the tablespace in question:


SELECT tablespace_name, max_data_files
FROM dba_tablespaces
WHERE tablespace_name = 'YOUR_TABLESPACE_NAME';

Replace ‘YOUR_TABLESPACE_NAME’ with the name of the tablespace where you are encountering the error. This query will return the current value of the MAXDATAFILES parameter for the specified tablespace.

Fixing the ORA-01638 Error

To fix the ORA-01638 error, you need to specify a valid value for the MAXDATAFILES parameter. The valid range for this parameter is platform-dependent, so you will need to consult the Oracle documentation for your specific platform to determine the appropriate range.

Once you have determined the valid range for the MAXDATAFILES parameter, you can alter the tablespace to set the correct value. For example, if the valid range for your platform is 1 to 1024, you can run the following SQL statement to set the MAXDATAFILES parameter to 100:


ALTER TABLESPACE YOUR_TABLESPACE_NAME
MAXDATAFILES 100;

Replace ‘YOUR_TABLESPACE_NAME’ with the name of the tablespace where you are encountering the error, and ‘100’ with the appropriate value for your environment.

If you are creating a new tablespace and encountering the ORA-01638 error, you can specify the correct value for the MAXDATAFILES parameter in the CREATE TABLESPACE statement.

Additional Considerations

When diagnosing and fixing the ORA-01638 error, it is important to consider the following:

– Check the Oracle documentation for your specific platform to determine the valid range for the MAXDATAFILES parameter.
– Always back up your database before making any changes to tablespace parameters.
– If you are unsure of the appropriate value for the MAXDATAFILES parameter, consult with your database administrator or Oracle support for assistance.

In conclusion, the ORA-01638 error in Oracle is caused by specifying an invalid value for the MAXDATAFILES parameter. By diagnosing the error and setting the correct value for this parameter, you can resolve the issue and continue working with your tablespace.

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