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 schema where all tables have the same Primary Index

Answer

A distributed schema across multiple Teradata nodes

Answer

A schema using only views with no base tables

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 are small; dimension tables are large

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Fact tables store current data; dimension tables store historical data

Answer

Fact tables use UPI; dimension tables use NUPI

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

Overwrites the existing record with the new value

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Adds a new column for each attribute change

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Stores only the first and last versions of a record

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

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Stores aggregated historical data for strategic analysis

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Acts as a staging area for raw ETL data before cleansing

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Holds archive data older than a defined retention period

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

Execute, Test, Launch — a software deployment methodology

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Encrypt, Transfer, Log — a data security process

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Extract, Translate, Link — a schema mapping process

Question 6

What is a surrogate key in a Teradata dimensional model?

Accepted Answer

A system-generated integer key used as the Primary Index of a dimension table, replacing the natural key

Answer

A foreign key linking a fact table to a dimension table

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A composite key made up of multiple natural key columns

Answer

A key automatically generated by Teradata's IDENTITY column