Using Log Files

1. Browse the log file for the most recent error that matches the error number you have received from the application. This is almost always the last entry in the log file. Notice that an entry or error stack in the log file is usually many lines in length. In the example, the error number was 12203.

2. Starting at the bottom, look up to the first non-zero entry in the error report. This is usually the actual cause. In the example, the last non-zero entry is the "ns" error 12560.

3. Look up the first non-zero entry in later chapters of this book for its recommended cause and action. (For example, you would find the "ns" error 12560 under ORA-12560.) To understand the notation used in the error report, see the section, "Sorting Out Networking Error Messages,".

4. If that error does not provide the desired information, move up the error stack to the second to last error and so on.

5. If the cause of the error is still not clear, turn on tracing and re-execute the statement that produced the error message. The use of the trace utility is described in detail in the next chapter. Be sure to turn tracing off after you have re-executed the command.