Flatten converts a field of values e.g. JSON repeated fields into a set of rows. LATERAL allows us to tie that set of rows to 'a higher level' in the JSON document hierarchy. Taking the first LATERAL FLATTEN statement in the video as an example, this allows us to tie the separate rows from the 'data' array back to the 'city' level of the JSON document (a city can have lots of weather readings).
Excellent presentation, learned more from this one presentation about DV2.0 than from reading many blogs, thank you!!!
Good presentation...thank you for uploading
Great Presentation! Thank you!
"The Elephant in the Fridge" by John Giles
Wow nice!
41:08 What was the need for LATERAL here?
Flatten converts a field of values e.g. JSON repeated fields into a set of rows. LATERAL allows us to tie that set of rows to 'a higher level' in the JSON document hierarchy. Taking the first LATERAL FLATTEN statement in the video as an example, this allows us to tie the separate rows from the 'data' array back to the 'city' level of the JSON document (a city can have lots of weather readings).