Checking an Instance s Alert Log File

Checking an Instance's Alert Log File

Just because the DBA's database servers, listeners, and instances are up does not mean that all is perfectly well. Problems might very well exist that should be addressed. For example, one of the Oracle background processes may have improperly terminated , yet people can still successfully connect to the database. Thus the Instance Manager screen gives the Oracle DBA a fifty-thousand- foot view, for it merely performs simple tests such as ping and tnsping and connects to the database. So the DBA should dig a bit deeper to be sure that all is really well.

Unfortunately, there is no quick and easy screen within TOAD to perform such detailed checks. Nonetheless, you still can utilize TOAD to find out where that information is and even possibly to access it.

Oracle creates and maintains an alert log file in the background dump destination directory, pointed to by the database instance parameter BACKGROUND_DUMP_DEST. Although you could reference the INIT.ORA file to determine this setting, TOAD offers at least three other ways to easily discover the same information:

• Inspect data for the Oracle Parameters window, opened from the main menu at DBA, Oracle Parameters and depicted in Figure 5.5.

  Figure 5.5. TOAD Oracle Parameters screen.

  

• Perform a SELECT against table V$PARAMETER in a TOAD SQL Editor window.

• Inspect the data for view SYS.V_$PARAMETER by using a TOAD Schema Browser window.

After you have the information for where the alert log file is located, it depends on your database server's operating system as to what you do next . For Windows-based Oracle database servers, you can simply use Windows Explorer and Notepad to locate and examine the file ( assuming that you can either map the network drive or log in to the proper Windows database server). For UNIX-based Oracle database servers, you should use TOAD's telnet interface on the Network Utilities screen, located on the main menu at File, Network Utilities.

Figure 5.6 shows an example of logging into a Linux database server and examining the alert log file using the tail command. As you can see, there are no hidden or otherwise unobserved database errors. Of course, the smart DBA would probably do a more sophisticated command with a larger portion of the log file, such as tail “100 alert.log grep ORA- .

Figure 5.6. Checking the alert log file using TOAD's telnet.