apache beam - Is a Source that has unknown but limited elements considered BoundSource or UnboudSource?

Question

Is a Source that has unknown but limited elements considered BoundSource or UnboudSource?

If I would be able to implement both BoundSource and UnboudSource, which one is "better"? By "better" I mean which would offer more options or better performance?

I'm going to crawl a website that has pagination, so initially, I do not know how many pages will I crawl, however, I am sure that it's not infinite.

Answer 1

BoundedSource will allow you to run the job as a batch job, which will likely be faster. The only reason to use UnboundedSource instead here would be if you wanted to process the data as it was read in, instead of all at once after it all has been read.