Apache Spark / Basic: typed relational foundations
Apache Spark β Basic: typed relational foundations
Locate execution, preserve measurement meaning and build correct query populations and totals.
What you will learn
- Explain laziness, schemas, NULL, ANSI behavior and time boundaries.
- Validate joins and aggregate completeness at the intended grain.
Driver, executors and lazy plans
Locate a DataFrame operation in Spark execution and distinguish constructing a plan from computing its result.
Start learningSchemas, types and source boundaries
Read meter data through an explicit typed contract and preserve rejected values for diagnosis.
Start learningColumn expressions, NULL and ANSI behavior
Make missing values and invalid measurements explicit instead of hiding them inside casts or Python control flow.
Start learningFiltering, time zones and deterministic order
Express a reporting interval and stable output without confusing event instants, wall clocks and partition order.
Start learningJoins, grain and reference data
Enrich readings without multiplying energy or losing sites whose reference data is incomplete.
Start learningAggregations and completeness metrics
Summarize energy with an explicit population, denominator and missing-reading policy.
Start learning