Managing Redo Log Files


Managing online redo log files is not something that is done very often, but it can have dramatic impact upon a database's performance. Often when a database is initially created, DBAs may specify too few groups or size the members too small. Or if additional volumes are available for database use, the DBA may need to add additional members across different locations for availability purposes. Whatever the reason, there are times when a DBA needs a friendly and efficient interface for managing all aspects of online redo log files. TOAD provides such a screen in the Redo Log Manager screen shown in Figure 6.60 and located on the main menu at DBARedo Log Manager.

Figure 6.60. TOAD Redo Log Manager screen ” iconic.

This screen is very neat and compact, yet it provides a plethora of capabilities. It displays information about the current log file and the last log switch. It supports forcing log switches and adding or dropping of groups and members. It also displays all the members and groups currently allocated. In the case of Figure 6.60, it shows that there are four groups. Two groups have two members each and two groups have but one member each. This reflects an imbalance because ideally you should have equal numbers of members across all groups and those members ought to be the same size. Hence TOAD indicates this imbalance by marking the offending groups in red. Note that the grid permits three different display styles for the member and group information: by icon, file size, and filename. In Figure 6.60, the display is shown using the icon format. The green checks mean OK and the red X's mean not OK (unlike other places in TOAD where these icons mean online and offline). Notice that when sufficient members have been added and the display mode is switched to file size, the screen now appears in all green as shown in Figure 6.61.

Figure 6.61. TOAD Redo Log Manager screen ”file size.

The Redo Log Manager screen also displays the status of the archive log mode process, running or not. There is also support for starting and stopping the archive log mode process, as well as manually archiving current, all, next , or group. Plus you can specify the location where the log file should be archived. Remember that you must specify that filename based on the database server environment because the database server process on the database server machine will perform that archive process.



TOAD Handbook
TOAD Handbook (2nd Edition)
ISBN: 0321649109
EAN: 2147483647
Year: 2003
Pages: 171

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