|Subject:||ReDo Log Advice from ixora web site|
|Posted by:||Charles (cdavis107…@comcast.net)|
|Date:||22 Apr 2004|
the ixora web site give this advice about keeping ReDo log files open.
Do the experts in this group generally concur with this advice?
Copy/Paste from ixora web site:
Holding the log files open
The greatest potential for tuning the speed of a log switch is in the
opening of the new log file members. The operating system's open()
system call is much faster if another process already has an open file
descriptor on the same file. This is partly because certain
information about the file is already cached in kernel memory. But
more importantly in the case of raw logical volumes, it avoids a delay
while logical volume state data reflecting the opening of the raw
logical volume is written to the volume group reserved area on disk.
The APT script hold_logs_open.sh is intended to be run daily from cron
under Unix to hold all the log files for an instance open for the next
24 hours. The first time we tried this technique, it shaved an
impressive 6 seconds of the speed of each log switch. Your mileage
will vary depending on your logical volume or file system and kernel
configuration, but it is sure to help a little.