Teradata Teradata Data Warehousing

Question 1

What is a star schema in the context of Teradata data warehousing?

Accepted Answer

A design with a central fact table surrounded by denormalized dimension tables

Answer

A star schema has a central fact table containing measurable business events and surrounds it with denormalized dimension tables describing the context of those events.

Question 2

What is the difference between a fact table and a dimension table in Teradata?

Accepted Answer

Fact tables store measurable quantitative data (metrics); dimension tables store descriptive attributes

Answer

Fact tables contain numerical measures (sales amount, quantity) and foreign keys to dimensions, while dimension tables contain descriptive attributes (product name, customer city) used for filtering and grouping.

Question 3

What is a Slowly Changing Dimension (SCD) Type 2 in data warehousing?

Accepted Answer

Adds a new row for each change, preserving full history with effective date columns

Answer

SCD Type 2 inserts a new row for each attribute change, keeping all historical versions with start/end date or a current-flag indicator.

Question 4

In Teradata data warehousing, what is the purpose of an ODS (Operational Data Store)?

Accepted Answer

Provides near-real-time integrated data from multiple operational systems for tactical decisions

Answer

An ODS integrates current-state data from multiple source systems at a low latency, supporting operational reporting and short-term tactical decision-making.

Question 5

What is the ETL process in data warehousing?

Accepted Answer

Extract, Transform, Load — the process of moving and preparing data from source systems into a warehouse

Answer

ETL extracts data from operational sources, transforms it (cleansing, aggregation, enrichment), and loads it into the target data warehouse for analysis.

Teradata Practice Test

Teradata Practice Test

Teradata Teradata Data Warehousing