Field note · November 30, 2023
Cutting a lesson down — What a pipeline is really doing
Extract, load, transform — why the industry flipped the last two letters, and what a pipeline owes you beyond moving bytes.
A note from writing What a pipeline is really doing, which took three passes to get to something short.
Extract, load, transform — why the industry flipped the last two letters, and what a pipeline owes you beyond moving bytes.
The hard part of writing this was cutting it. The first version covered every case; the useful version covers the case you hit on a Tuesday and names the rest in a sentence. Completeness is a property of reference material, not of teaching material, and confusing the two produces something nobody finishes.
It sits in the Getting the data in module. The exercise is a thinking one rather than a query one — some of this material is about deciding what to compute, and that does not need a keyboard.
Ordering matters here more than in most courses. It follows A working setup that will not embarrass you and leads into Batch, streaming, and the honest difference, and reading it out of sequence mostly works but costs you the setup.
Free means free, and it also means we can rewrite it whenever it is wrong. No edition, no errata PDF, nothing to repurchase. The whole course is 36 lessons and the fixes land the day we find them.