Teradata Interview Questions and Answers

BTEQ or Basic Teradata Query Script is a file present in Teradata which contains BTEQ commands and SQL statements. The BTEQ script is built for command sequences that are going to be executed on more than one occasion, which can be daily, weekly or monthly.

There have four table types supported in Teradata:

• Permanent Table: It’s the default table and contains data put by the user and stores that data permanently.
• Global Temporary Table: Persistent but the data present in the table will be deleted at the end of the user session.
• Volatile Table: The data into this table is retained only during the user session.
• Derived Table: It holds the intermediate results in a query. The lifetime of this table depends on the query in which they are created, dropped and used.

This is a fundamental question in teradata interview questions.

In Teradata, the primary index is an index present on a set of fields which includes the primary key for the field and is guaranteed not to contain any duplicates.

There are two types of primary indexes:

• UPI / Unique Primary Index
• NUPI /Non-Unique Primary Index

Enlisted new features added to the Teradata:

• New string functions added; PIVOT and UNPIVOT
• Addition of DATASET datatype
• Performance improvement in COUNT DISTINCT
• Introduction of Global Space Accounting
• Unicode Pass-Through added
• Increased PERM and Response Rows (1 MB)
• More choice added to Compression Table-Level Option

In Teradata, fastload is a utility which can be used by developers to load a large amount of data in an empty table on a Teradata system. Its unique features include increased speed to load a huge amount of data in tables.

In Teradata, FastExport is a utility used to export data from Teradata tables into flat files. Teradata – FastExport can also generate the data in report format,

Developers use the UPSERT command inserts rows that do exist. It can be achieved using UPDATE-ELSE-INSERT or MERGE.

Here are the common data types used in Teradata:

• Byteint
• Smallint
• Integer
• Bigint
• Decimal
• Numeric
• Float
• Date
• Varchar
• Time
• Timestamp

Node is a term used for the processing unit (General Purpose) which is controlled by a single operating system. Node is known as the basic building block of Teradata System. The Node is the destination where the processing occurs for the database.