Tera Data Interview Questions and Answers
Question - 41 : - What happens when a node suffers a downfall?
Answer - 41 : -
Whenever there is a downfall in the performance level of a node, all the corresponding Vprocs immediately migrate to a new node from the fail node in order to get all the data back from common drives.
Question - 42 : - What is meant by a Clique?
Answer - 42 : -
A Clique is basically known to be an assortment of nodes that is being shared amongst common disk drives. Presence of Clique is immensely important since it helps in avoiding node failures.
Question - 43 : - In Teradata, what is the significance of UPSERT command?
Answer - 43 : -
UPSERT basically stands for Update Else Insert. This option is available only in Teradata.
Question - 44 : - Highlight the advantages of PPI(Partition Primary Index).
Answer - 44 : -
PPI is basically used for Range-based or Category-based data storage purposes. When it comes to Range queries, there is no need of Full table scan utilization as it straightaway moves to the consequent partition thus skipping all the other partitions.
Question - 45 : - What is meant by a Least Cost Plan?
Answer - 45 : -
A Least Cost Plan basically executes in less time across the shortest path.
Question - 46 : - Highlight the points of differences between the database and user in Teradata.
Answer - 46 : -
- A database is basically passive, whereas a user is active.
- A database primarily stores all the objects of database, whereas a user can store any object whether that is a macro, table, view, etc.
- Database does not has password while the user has to enter password.
Question - 47 : - Highlight the differences between Primary Key and Primary Index.
Answer - 47 : -
- Primary index is quite mandatory, whereas Primary Key is optional.
- Primary Index has a limit of 64 tables/columns, whereas Primary Key does not have any limit.
- Primary Index allows duplicates and nulls, whereas Primary Key doesn’t.
- Primary Index is a physical mechanism, whereas Primary Key is purely logical mechanism.
Question - 48 : - Explain how spool space is used.
Answer - 48 : -
Spool space in Teradata is basically used for running queries. Out of the total space that is available in Teradata, 20% of the space is basically allocated to spool space.
Question - 49 : - Highlight the need for Performance Tuning.
Answer - 49 : -
Performance tuning in Teradata is basically done to identify all the bottlenecks and then resolve them.
Question - 50 : - Comment whether bottleneck is an error or not.
Answer - 50 : -
Technically, bottleneck is not a form of error, but it certainly causes a certain amount of delay in the system.