This section describes using the plog, addlog and droplog functions of the space service to manage the physical and logical logs. These logging spaces are used as part of the Informix database recovery mechanisms.
naming conventions
When you create a storage space that will only contain the physical log, the name should be plog, or at least start with "plog" e.g. plog01.
When you create a storage space that will only contain logical logs, the should start with log ie log01 or log02.
The Backup & Recovery dashboard also uses this information. It tracks the progress of the instance clearing the physical and logical logs after a restore.
Using these names is not mandatory, they are only relied on for cosmetic purposes.
physical log
The physical log is part of Informix's recovery mechanism that records before images of modified database pages. As part of instance management you may need to move or re-size this log.
For example, create a new storage space called plog of 100mb and relocate the physical log to this space.
infx space func=new space=plog size=100
infx space func=plog space=plog size=95
logical logs
The logical logs record transaction information for recvvery purposes.
Create a new storage space for logical logs, and then create the logical logs.
infx space func=new space=log size=100
infx space func=addlog space=log size=10
infx space func=addlog space=log size=10
...
...
Each logical log has a number, assigned when it is created. You use this number to delete the logical log. You can only delete logs that are not in use and have been backed up.
Example, drop logical log number 1.
infx space func=droplog number=1
