Can analyzing data from an existing public online database be considered orginal work?
Yes, the analysis is original, provided that you haven't been beaten to it by someone else. Data is just data, but it is the analysis that gives it meaning. Extracting that semantic content is what is important in research.
But &quot;summarizing&quot; may not be enough, depending on what you do.
And the source of the data has little bearing on the validity of the analysis.
Of course, editors and reviewers will have a say in the value of the work.