Cognos

You can upload the following file formats:

• Excel files: .xls and .xlsx only.
• Delimiter-separated value files: .csv, .tsv, .tab, or .txt.
• Jupyter files: .ipynb
• Compressed files: .zip and .gz files.

For a deep dive into the official documentation, rules, and best practices, see the IBM Cognos Analytics Uploaded Files Guide.

Uploaded files are converted into an Apache Parquet file format and stored within the Content Store Database. When initially uploaded, they are immediately available in your My Content area.

Size Limits: By default, individual files are capped at 100 MB, and the total limit for all uploaded files is 500 MB.

Uploaded files and data sets are stored in a columnar database which resides on the Cognos Analytics application tier.

Uploaded data is available to everybody by default. However, the initial entry itself is placed privately in the uploading user's personal folder.

You should not need to re-upload your files. Utilizing proven deployment and migration practices will safely bring all of your uploaded data resources over to the new environment.

If your source file experiences a structural change—such as columns being added, removed, reordered, or renamed—it is recommended to completely delete and re-upload the file. Using the "update only (values)" option will not work for structural edits.

A data server connection acts as a direct pathway to your live database, meaning it will query the underlying database every single time a report or object is run.

Pro-Tip: You can create a standalone data set based on that data server connection. A data set acts as a data extract package that physically lives cache-stored on the Cognos Analytics server for faster performance.

The Cognos BI server connects directly to the database, so network connectivity and firewall permissions must live on the server itself. No direct connectivity is required from individual client web browsers to the physical data sources.

Yes. Data server credentials are set at the highest administrative level. The owner of the data server connection can then assign specific permissions and access to underlying tables and schemas by user or user group.

Yes, you can easily hide columns within your data modules to keep them clean for end-users.

No. With a data module, you are building an isolated metadata model that blends your existing packages, data server tables, and uploaded files. You will not alter or make any permanent changes to your original standalone packages.

Not directly within the raw data set. You must first build a data module on top of that data set. From there, you can use the Navigation Paths feature to create your desired drill paths and hierarchies.

If a data set refreshes while a user is actively viewing a dashboard, the dashboard will need to be manually re-run or reloaded to display the new data. However, the dashboard automatically pulls the newest data cache every single time it is opened fresh.

While default color palettes can be toggled inside the UI, truly customizing the available colors to match exact corporate branding requires modifying the underlying system stylesheets on the server.

Chart visualizations are built on the RAVE2 engine, meaning JSON remains the standard format.

Reusing legacy report components inside the new dashboard environment is not directly supported natively. IBM has placed this capability onto the core product development roadmap.

No, native global deployment of a forced custom homepage per user group is not widely supported out-of-the-box.

Legacy portal pages are not directly supported in the modern interface, as the system has transitioned toward modern dashboarding and landing tab configurations.

Active Reports are fully available and remain a core piece of the reporting toolset—especially as the go-to solution for offline mobile consumption. Conversely, Cognos Insight is no longer a primary development focus for IBM.

Yes. By using the Share and Embed action panel, you can instantly copy the unique URL of a report. You can use this URL to iframe or embed reports into external sites, though viewers will still be prompted to log in with a valid Cognos license to view the data.

Cognos runs smoothly across all major supported browsers. While modern development heavily favors Google Chrome and Mozilla Firefox, legacy stability is maintained for modern variations of enterprise browsers (like IE 11/Edge) assuming compatibility settings are correct.