I have thousands of .csv files with the same structure and, in most of the cases, some column values are the same ones recurring. Each file represents a report on some structures, with numeric attributes and a date.
I want those to be structured and suitable for cleaning missing values, visualizations, predictions, etc. and I know that several ETL tools are designed to provide this, although I never learned to use one.
But I cannot figure out how my "integrated" data will look like: the names of my structures are recurrent and the csv reports are a few minutes apart one from another: what does commonly happen in an ETL system in those scenarios? Is really ETL the right thing? Do I have to know in anticipation which operation I will perform on the "structured" data (e.g. predictions, temporal roll-ups, etc.) to choose (let's say) an SQL-like output or the "philosophy" is just a different one?