Teradata MCQ Flashcards

What is the maximum number of levels supported in a Teradata multi-level partitioned primary index (MLPPI)?

Answer: 32

Teradata supports up to 32 levels of partitioning in a multi-level partitioned primary index.

In Teradata, which join type performs best when one table fits entirely within the spool space of a single AMP?

Answer: Nested Join

A Nested Join is efficient when the smaller (inner) table can be replicated to each AMP and row lookups use the primary index.

Which Teradata data type is most appropriate for storing monetary values requiring exact decimal arithmetic?

Answer: DECIMAL/NUMERIC

DECIMAL/NUMERIC stores exact fixed-point values, avoiding the rounding errors inherent in floating-point types.

What does the 'LOCKING FOR ACCESS' modifier do in a Teradata SQL statement?

Answer: Allows dirty reads by acquiring the lowest-level lock

LOCKING FOR ACCESS acquires an access lock, the weakest lock level, permitting reads of potentially uncommitted data.

In Teradata, what is a 'Global Temporary Table'?

Answer: A table whose definition persists but data is session-scoped

Global Temporary Tables have a permanent table definition in the data dictionary but data inserted is private to and lasts only for each user session.

Which Teradata utility supports both insert and update/delete operations on existing populated tables in a single pass?

Answer: MultiLoad

MultiLoad supports up to five concurrent DML operations (INSERT, UPDATE, DELETE, UPSERT) on up to five tables in a single job.

What is the role of the Teradata 'Parsing Engine' (PE)?

Answer: It parses SQL, creates execution plans, and dispatches steps to AMPs

The Parsing Engine receives SQL from clients, parses and optimizes it, then dispatches execution steps to the appropriate AMPs.