Answer by Marek for String columns are not listing inside the metrics, only allowed to select numeric column types from the metrics while creating report in GoodData

I would recommend to check GoodData documentation for platform beginners to get understanding about basic concepts. There is tutorial which will be good start - https://help.gooddata.com/display/doc/GoodData+Developer+Tutorial. There is part for Concepts - https://help.gooddata.com/display/doc/Concepts and also for Creating Metrics & Reports - https://help.gooddata.com/display/doc/Creating+Metrics+and+Reports In your particular case I suggest you are aiming for adding Attribute to your report, which can be achieved in "How" section.