Teradata Interview Questions
An Overview of Teradata
Developed by Teradata Corporation, Teradata is one globally renowned, and most developers preferred Relational Database Management Systems. Suitable to build large scale data warehousing applications, the database system of Teradata is primarily based on off-the-shelf symmetric multiprocessing technology with a combination of communication networking, which results in connecting symmetric multiprocessing systems to create large parallel processing systems. Here is a thoroughly selected list of Teradata interview questions prepared by top Teradata experts globally. Practicing with these Interview questions and answers will help you much to crack your next big interview.
The system acts as a single data store that accepts a vast number of concurrent requests from multiple client applications. With the developers of outstanding features such as parallelism along with distribution load shared among several users, execution of complex queries, complete scalability, parallel efficiency and more; today Teradata is one of the most business preferred Relation Database Management Systems worldwide, creating countless job opportunities in its niche. If you are an active job pursuer in this niche, then follow us further here to get the set of most interviewers preferred Teradata interview questions and appropriate answers for them.
- It holds a scalable database. Any developer, with the help of hardware and nodes, can expand capacity.
- Its parallel nodes can help you handle n-number of the ad-hoc request.
- Access to full table scans performance improvement.
Most Frequently Asked Teradata Interview Questions And Answers With Examples:
- What is teradata and why it is used?
- What are the advantages of Teradata?
- Explain Teradata architecture?
- How is the Teradata different from Oracle?
- What do you mean by Teradata SQL Assistant?
- How to run a query in Teradata?
- Explain Teradata vs. redshift?
- What do you mean by Teradata IntelliCloud?
- What do you mean by Teradata Intelliflex?
- What do you mean by TTU in Teradata?
- What is BTEQ script in Teradata?
- What are different table types used in Teradata?
- What is the primary index in Teradata?
- Explain the new features of Teradata?
- Explain fastload in Teradata?
- What do you mean by fastexport in Teradata?
- What is the use of UPSERT COMMAND In Teradata?
- Explain the most common data types used in Teradata?
- What do you mean by Caching in Teradata?
- What is a node in Teradata? Explain
- Explain parsing engine in Teradata?
- Explain vproc in Teradata?
- Explain fallback in Teradata?
- What are Teradata utilities?
- What do you mean by TPT in Teradata?
- What is the difference between union and union all in Teradata?
- Explain the types of join supports by Teradata?
Teradata is a vast parallel open relation data management and processing system primarily used to develop large scale warehousing applications. As this is an open system, it can operate on Linux, Unix and Windows server platform. It also provides support to multiple data warehouse operations at the same time to different clients.
Teradata is based on MPP or Massively Parallel Processing architecture. Again, the MPP architecture of Teradata has three core components:
- Parsing Engine (PE) or Optimizer
- Access Module Processor (AMPs)
- Messaging Layer (BYNETs)
|1.||Database Management System primarily used for data analytics.||Widely used Relational database management systems|
|2.||Server operating system: Linux.||Server operating system: AIX, HP-UX, Linux, OS X, Solaris, windows.|
|3.||APIs and another access method: .NET Client API, HTTP REST, JMS Adapter, JDBC, ODBC and OLE DB.||APIs and another access method: ODP.NET, JDBC, ODBC and Oracle Call Interface (OCI)|
|4.||Horizontal partitioning method used.||Sharding partitioning method used.|
Teradata SQL assistance is an advanced web-based query tool which developers used to store, retrieve and manipulate data from Teradata Database or any other database with an ODBC interface Its Java Edition can be used to attach to Teradata Database or any other database that provides the JDBC interface.
|1.||DBMS primarily used for data analytics||A large scale data warehouse service to be used with business intelligence tools.|
|2.||Not based cloud||Cloud-based only|
|3.||Linux server operating system||Hosted server operating system|
|4.||Offers XML support.||No XML support.|
|5.||Offers secondary indexes.||I have restricted secondary indexes.|
|6.||Has triggers||No Triggers|
Teradata IntelliCloud is an as-a-service offering for analytics at scale. It enables businesses to focus on analytic workloads and data warehousing while relying on Teradata for the setup, maintenance, management and support of the infrastructure and software.
Teradata Intelliflex is a platform specially designed for scalable enterprise analytics. It uses an advanced self-service software controls and MPP architecture for scaling of processing data and power capacity independently.
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
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:
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.
In Teradata, Vproc or Virtual Processor is a simulated processor present in a processing software system, or in a software version of a dedicated physical processor. Each of Vproc uses a portion of the physical processor resource and runs independently of another virtual processor.
In Teradata, Fallback is a feature that offers enhanced data protection beyond that provided by redundant hardware components. Fallback is enabled when a failure occurs, Teradata can continue to perform the update, delete and insert functions because redundant copies of data exist on one or more fallback AMPs.
TPT or Teradata Parallel Transporter is a new generation and advance load/unload utility provided by Teradata. TPT acts as an integrated ETL suite that helps to extract data from multiple sources, load data in target Teradata database and apply transformation logic.
|1.||It removes duplicate records where all columns in the results are the same.||It doesn’t remove duplicate records where all columns in the results are the same.|
|2.||The performance will be impacted with the use of Union as additional work will be performed to remove duplicate rows.||The performance will not be impacted.|