H29 Compare deliveries

Use your current course session. Preparation and course runner · R script ↓

H29 Compare deliveries

Goal: Retain a deliberate data change in history.

Prerequisites: H28.

The comparison uses policy_id as the business key.

training_step(
  "H29",
  {
    lake_second_data <- policies
    lake_second_data$premium[1] <- 110
    lake_second <- dr_publish(
      lake_product,
      data = lake_second_data,
      business_date = "2026-08-31"
    )
    lake_difference <- dataraft.lake::dr_compare(
      lake_first,
      lake_second,
      key = "policy_id"
    )
    print(lake_difference)
    stopifnot(sum(dr_collect(lake_second)$premium) == 750)
  },
  needs = c("H28"),
  enabled = training_options$lake,
  optional = TRUE
)

Expected result: Policy 1 changed; the new total is 750.

Task: Why do both runs have the same business_date?