Dev : Informix's Logical Log Files 2

I once wrote something on Informix's logical log file issue. After some research online and reading the manual, I can conclude that, for an Informix DBA, most importantly is to frequently monitor the database's logical log file.

As we do an "onstat -l", you might notice something like this:

8cd23475 U------ 1234 1:12345 1000 1000 100.00
8cd23476 U------ 1235 1:23423 1000 1000 100.00
8cd23477 U---C-L 1236 1:65434 1000 750 75.00
8cd23478 U-B---- 1237 1:15543 1000 1000 100.00
8cd23479 U-B---- 1238 1:12553 1000 1000 100.00

Some of the most important thing you might want to see is the "B", "C" and the last number column.

Remember this, the database will stop functioning when the next logical file is not backup. It does not concern whether the next is fill up or not, instead, backed up or not is more important. The last number column will stat the percentage of the logical file being used. So when it reaches 100%, it will move over to the subsequent file.

So, how to determine which logical log file is in use now? Noticed the "C"? It means the current logical log file is being written. For this case, it will continue to write the current, the next, and the next to the next's logical log file. When it reaches back to the 1st logical log file, the database will stop functioning. So, it is better to alway to backup the logical log file, "ontape -a", as often as possible. Maybe once a week?

"B" stands for backup-ed. So meaning that after a backup is being done, you will notice that all the logical log file will have a "B", except for the current logical logfile.

This is what I have understand after reading. I cannot assure that I am 100% correct, but then, hopefully it helps. Happy exploring!