Introduction To Data Engineering Flashcards

What is a DAG in the context of data workflow orchestration?

Answer: A Directed Acyclic Graph defining task dependencies without cycles

A DAG models tasks and their dependencies as nodes and edges with no cyclic loops.

Which concept ensures a database transaction is reliable through Atomicity, Consistency, Isolation, and Durability?

Answer: ACID properties

ACID properties guarantee that transactions are processed reliably even during failures.

What is data lineage?

Answer: A record of data's origin, movements, and transformations over time

Data lineage tracks where data comes from and how it changes as it flows through systems.

Which storage approach uses schema-on-read?

Answer: Data lake

Data lakes store raw data and apply structure only when the data is read or queried.

What is the purpose of an index in a database?

Answer: To speed up data retrieval at the cost of extra storage and slower writes

Indexes accelerate lookups but add storage overhead and slow down inserts and updates.

Which term describes combining data from multiple sources into a unified view?

Answer: Data integration

Data integration merges data from disparate sources into a single coherent dataset or view.

What does OLTP stand for and primarily support?

Answer: Online Transaction Processing for high-volume operational reads and writes

OLTP systems handle many short transactional operations like inserts and updates in real time.