If you want to do some quick analysis and visualizations with data files, you can upload them to IBM Cognos Analytics yourself and use them in dashboards and stories. Uploaded files are also used as sources for data modules.
You can upload simple data files of up to 100 MB from your local drive. Administrators can increase the file size limit, but must be aware of file upload size limits for browsers. The data must be in columnar form - no pivot tables or crosstabs.