Teradata For Beginner 3 — Questions and Answers
Question 1: Which Teradata utility is used to load large volumes of data into an empty table at high speed?
- FastExport
- MultiLoad
- FastLoad (Correct answer)
- BTEQ
Correct answer: FastLoad
FastLoad is designed for bulk loading data into empty tables very quickly by bypassing the transient journal.
Question 2: What is the role of the Parsing Engine (PE) in Teradata?
- It stores and retrieves rows from disk
- It parses SQL, optimizes queries, and dispatches work to AMPs (Correct answer)
- It manages network communication between nodes
- It handles user authentication only
Correct answer: It parses SQL, optimizes queries, and dispatches work to AMPs
The Parsing Engine receives SQL statements, parses them, creates an execution plan via the optimizer, and coordinates AMP activity.
Question 3: In Teradata, what is a Volatile table?
- A table stored in RAM for faster access
- A temporary table that exists only for the duration of the session (Correct answer)
- A table that auto-deletes rows older than 24 hours
- A table with no primary index
Correct answer: A temporary table that exists only for the duration of the session
Volatile tables are session-scoped temporary tables that are automatically dropped when the session ends.
Question 4: Which clause in Teradata SQL is used to filter groups after a GROUP BY operation?
- WHERE
- FILTER
- HAVING (Correct answer)
- QUALIFY
Correct answer: HAVING
The HAVING clause filters aggregated results after GROUP BY, while WHERE filters rows before aggregation.
Question 5: What does the EXPLAIN statement do in Teradata?
- Executes a query and shows row counts
- Displays the query execution plan without running the query (Correct answer)
- Shows table statistics and index definitions
- Lists all active sessions on the system
Correct answer: Displays the query execution plan without running the query
EXPLAIN returns the optimizer's execution plan in plain text, allowing you to understand how a query will be processed before running it.
Question 6: Which Teradata join strategy is used when both tables have the same Primary Index on the join column?
- Merge Join (Correct answer)
- Hash Join
- Duplication Join
- Nested Loop Join
Correct answer: Merge Join
A Merge Join is used when matching rows already reside on the same AMP, requiring no data redistribution across the network.
Question 7: What is the maximum number of characters for a VARCHAR column in Teradata?
- 255
- 1000
- 32000 (Correct answer)
- 64000
Correct answer: 32000
In Teradata, VARCHAR columns can store up to 32,000 characters (bytes) by default in Latin character sets.
Teradata For Beginner 3
Which Teradata utility is used to load large volumes of data into an empty table at high speed?