Hello all: I am using the ML Pipeline, which I consider very powerful. I have the next use case:
- I have three transformers, which I will call A,B,C, that basically extract features from text files, with no parameters. - I have a final stage D, which is the logistic regression estimator. - I am creating a pipeline with the sequence A,B,C,D. - Finally, I am using this pipeline as estimator parameter of the CrossValidator class. I have some concerns about how data persistance inside the cross validator works. For example, if only D has multiple parameters to tune using the cross validator, my concern is that the transformation A->B->C is being performed multiple times?. Is that the case, or it is Spark smart enough to realize that it is possible to persist the output of C? Do it will be better to leave A,B, and C outside the cross validator pipeline? Thanks a lot -- Cesar Flores