Teradata Teradata MCQ 5 — Questions and Answers
Question 1: Which Teradata compression type stores repeated column values once in the table header rather than in each row block?
- Multi-Value Compression (MVC) (Correct answer)
- Block-Level Compression (BLC)
- Algorithmic Compression (ALC)
- Row-Level Compression (RLC)
Correct answer: Multi-Value Compression (MVC)
Multi-Value Compression replaces frequently occurring column values with a small token stored in the row header, reducing row size.
Question 2: In Teradata, what is the maximum number of Secondary Indexes allowed per table?
- 16
- 32
- 64 (Correct answer)
- There is no fixed limit up to 32 per table
Correct answer: 64
Teradata allows up to 64 secondary indexes (USI + NUSI combined) to be defined on a single table.
Question 3: Which function in Teradata returns the position of the first occurrence of a substring within a string?
- POSITION() or INSTR() (Correct answer)
- SUBSTR()
- CHAR_LENGTH()
- INDEX()
Correct answer: POSITION() or INSTR()
POSITION(substring IN string) and its alias INSTR() both return the 1-based character position of the first match.
Question 4: What does the Teradata 'NORMALIZE' clause do when applied to a table of time periods?
- Merges overlapping or adjacent time periods into a single contiguous row (Correct answer)
- Converts date columns to canonical UTC format
- Removes duplicate rows from the result set
- Sorts rows by the period column
Correct answer: Merges overlapping or adjacent time periods into a single contiguous row
NORMALIZE collapses adjacent or overlapping PERIOD column rows with identical non-period attributes into a single merged row.
Question 5: Which Teradata view provides real-time information about currently running queries and their AMPs usage?
- DBC.QryLogV
- DBC.SessionInfoV (Correct answer)
- DBC.AMPUsageV
- DBC.ResUsageSawt
Correct answer: DBC.SessionInfoV
DBC.SessionInfoV shows active sessions and their current SQL text, state, and resource usage in near-real time.
Question 6: In Teradata, what distinguishes a Unique Secondary Index (USI) from a Non-Unique Secondary Index (NUSI)?
- USI guarantees one row per index value and uses 2 AMPs; NUSI allows duplicates and involves all AMPs (Correct answer)
- USI is stored on a separate disk; NUSI shares disk with the base table
- USI can only be defined on NOT NULL columns; NUSI allows NULLs
- USI supports range scans; NUSI only supports equality lookups
Correct answer: USI guarantees one row per index value and uses 2 AMPs; NUSI allows duplicates and involves all AMPs
A USI enforces uniqueness and accesses exactly 2 AMPs for a lookup; a NUSI allows duplicate values and typically scans all AMPs.
Question 7: Which Teradata Parallel Transporter (TPT) operator is used to read data from a Teradata table and export it to a flat file?
- Export operator (Correct answer)
- Load operator
- Stream operator
- DataConnector operator
Correct answer: Export operator
The TPT Export operator uses the FastExport protocol to read rows from Teradata and deliver them to downstream operators or files.
Teradata Teradata MCQ 5
Which Teradata compression type stores repeated column values once in the table header rather than in each row block?