Oracle alert files Conclusion

In this module we have taken a very close look at the Oracle alert log and observed its uses for the Oracle DBA. The main points of this module include:

1. You can quickly find the location of an alert log on any server by looking into server manager, or by looking at the init.ora file.
2. The alert log is specified by the backgound_dump_dest variable in the init.ora file.
3. The majority of messages in the alert log are non-emergency status messages such as database startup, shutdown, and log switch messages.
4. The alert log is the first place to look whenever an Oracle instance crashes, since the alert log will provide the names of all associated core dumps and trace files.
5. Some serious Oracle errors in the alert log may cause a task to terminate without causing the Oracle database to crash.
6. The Oracle DBA should develop a mechanism to constantly monitor the alert log for Oracle errors.

Question: What is the purpose of the backgound_dump_dest variable in the init.ora file?
Answer: The background_dump_dest variable in the init.ora file is used to specify the location of the trace files generated by the Oracle instance when an error or unexpected situation occurs. The trace files contain information about the state of the instance at the time of the error, including the values of variables, the call stack, and other diagnostic information.
The purpose of the background_dump_dest variable is to provide a centralized location for storing the trace files, making it easier for database administrators and developers to diagnose and resolve problems with the instance. By specifying a specific directory for the trace files, the DBA can ensure that the files are stored in a known location and are easily accessible when they are needed.
The background_dump_dest variable can be set in the init.ora file or in the spfile, and its value should be set to a valid directory on the file system of the Oracle server. For example:

background_dump_dest = /u01/app/oracle/admin/orcl/bdump

In this example, the background_dump_dest variable is set to the directory

/u01/app/oracle/admin/orcl/bdump, 

which is where the trace files generated by the Oracle instance will be stored.

It is important to note that the background_dump_dest variable should be set to a location that has sufficient disk space to store the trace files, and that is accessible to the user running the Oracle instance. By setting the background_dump_dest variable correctly, a DBA can ensure that the trace files are stored in a known location and are easily accessible when they are needed, which can greatly simplify the process of diagnosing and resolving problems with the instance.

Here are the terms from this module that may have been new to you.

1. alert log:Oracle Alert log file is where the Oracle database writes unexpected errors and special info that could be of interest for the Database Administrator. Sometimes it is not possible to access the file on the database server, then it is convenient to view the Oracle Alert Log file through this form.
2. grep utility:GREP (Global Regular Expression Print) is a powerful text search program derived from the UNIX utility of the same name. GREP searches for a text pattern in one or more files or in its standard input stream.
3. tail command:The tail command, as the name implies, print the last N number of data of the given input.

To wrap up this module, click the Quiz link below to take a short quiz on alert files.
Alert Log Concepts - Quiz