IBM Cognos User Manual page 211

This setting specifies the log file name. You can include the full path with the
file name.
If you do not specify the file name, the output is displayed on the screen, which
is the product default.
On Windows, if the log file name is not specified, a model name or a generated
name, such as tfmr0001.log, is used and the .log extension is added.
On UNIX, if the log file name is not specified or set to stdout, the output is
displayed on the screen.
v <Preference Name="LogFileAppend" Value="FALSE"/>
This setting specifies that the log file is overwritten for each new model or cube.
A value of TRUE appends the new log data to the existing log file.
v <Preference Name="LogDetailLevel" Value="4"/>
This setting specifies the types of messages that are written to the log file.
Choose from the following severity levels:
– 0 - suppresses logging
– 1 - includes severe errors only, which must result in corrupted files or
inconsistent data
These can arise if limits are exceeded for CPU, disk, file, or transaction
resources, or if the model, cubes, or temporary files have been corrupted.
– 2 - includes severe errors and errors that occur at the transaction level
These cause the cube to be invalid, but leave it in a consistent, possibly
incomplete, state.
– 3 - includes severe errors and warnings indicating a potential problem
Warning messages do not impede processing.
– 4 - includes severe errors, errors, warnings, and informational messages
(default)
You can use the log file to check the status of cube creation. The progress of a
cube update is indicated by statements in the file, each containing the following
fields:
– date and time (24-hour clock) at which the message was issued
– the message severity
– the message text
The text of each message includes header information, the ID of the object being
processed (in hex notation), and messages about Cognos Transformer processes
and timing.
Messages marked "Timing" are especially useful to analyze as a series of
processing events. You can do this by importing the log file into a spreadsheet
application as a tab-and-comma-delimited file. For more information, see"Using
the Log File to Analyze Processing Bottlenecks" on page 208.
Note: You can also use the -rcommand line option to control the types of
messages generated.
v <Preference Name="LoggingFrequency" Value="-1"/>
This setting specifies, in elapsed minutes, how often messages are written to the
log file. The default is -1. When the setting is -1, messages are not logged. If it is
set to 0, messages are written to the log file whenever they are generated.
Chapter 9. Guidelines for Optimizing Production Environments
197