Cognos create many temporary files when performing many activities such as generating reports and creating cubes. These are stored in the temp location which is specified in Cognos Configuration, under Environment.



By default this is <Cognos Installed directory> temp

If you have Transformer or Powerplay installed then you should also perform maintenance tasks on the following folder <Cognos Installed directory> datacqertmodels.

These files can sometimes be quite large in size and over time can take up a large amount of resource. It is good practice to remove these files on a regular basis. Below is a description of the most common files

The UDA file is the file with the data that is retrieved from the Database, and is the Cognos data workfile.

  • The CCLVPage file is the file that contains the report output, in the format specified by the report.
  • The dmbTempxxxxx.dmc file is the file that holds ‘cube’ data for the report, and is also a temporary file that gets created during the Report Run.
  • The Axisxxxaxis file is created by Event Studio.
  • There is also the CM directory, where the temporary PDF files will be created, named for instance CM_98765.tmp, and these are the output for any PDF report.
  • QYI files that are left over when Transformer doesn’t complete successfully


  • Stop all Cognos services
  • Delete all items from the temp folder
  • Delete all items in the RTModels folder BUT NOT THE FOLDER ITSELF
  • Start Cognos Services

If your Cognos environment is experiencing any problems please do not remove any files as they can help diagnose an issue.

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