Oracle log files view

Online redo log files that are not required for instance recovery are called inactive. The best way to determine the appropriate number of online redo log files for a database instance is to test different configurations. The optimum configuration has the fewest groups possible without hampering LGWR's writing redo log information.

In some cases, a database instance may require only two groups. In other situations, a database instance may require additional groups to guarantee that a recycled group is always available to LGWR. During testing, the easiest way to determine if the current online redo log configuration is satisfactory is to examine the contents of the LGWR trace file and the database's alert log.

If messages indicate that LGWR frequently has to wait for a group because a checkpoint has not completed or a group has not been archived, add groups. LGWR writes to online redo log files in a circular fashion. When the current online redo log file fills, LGWR begins writing to the next available online redo log file. When the last available online redo log file is filled, LGWR returns to the first online redo log file and writes to it, starting the cycle again.

The numbers next to each line indicate the sequence in which LGWR writes to each online redo log file. Use various elements in the log configuration file for a component to change these settings.

You can use the Log Viewer in Fusion Middleware Control to find messages that can assist you in resolving issues with the system. The Log Messages page is displayed. The Log Viewer collects lines from all log files and displays them on this page. You can filter the lines to view the ones in which you're interested. To start filtering the list, enter search criteria to locate the messages in which you're interested:. If you know that an error occurred around a certain date, then set the Date Range to Time Interval.

Select the start and end dates for filtering. If the error happens continually, then set the Date Range to Most Recent. Select Days and specify a number such as 1 or 3. If the number of messages that's returned is too large, then deselect Notification to see only errors and warnings. The advantage of selecting Notification is that you can see what the Oracle Analytics Server system was doing, which can assist you in determining where something went wrong.

Click Add Fields , then select Module , and click Add. Ensure that Module is set to contains , then enter the following value:. That value specifies the name of the Java package from which all log entries for systems management originate. The page lists all log messages that meet the criteria, including the errors and warnings that lead up to the problem that you're diagnosing. This file should constantly be monitored to detect unexpected messages and corruption.

Beginning with Release 11g, the alert log file is written as XML formatted and as a text file like in previous releases. The default location of both these files is the new ADR home Automatic Diagnostic Repository, yet another new dump dest in 11g.

Beginning with Release 11g of Oracle Database, the alert log is written as both an XML-formatted file and as a text file, as in earlier releases. Both these log files are stored inside the ADR home.

Within the ADR home directory are subdirectories where the database instance stores diagnostic data. XML formatted alert.