1. What is Teradata?
Teradata is a relational database management system (RDBMS) that is widely used for managing large data warehouses and business intelligence applications.

2. What are the key features of Teradata?
The key features of Teradata include massive parallel processing, scalability, high performance, and support for advanced analytics and parallel query execution.

3. What is a Primary Index in Teradata?
A Primary Index (PI) in Teradata is the mechanism used to evenly distribute rows across AMPs (Access Module Processors) in a Teradata system. It is used for data distribution and indexing in Teradata.

4. What is a Skew Factor in Teradata?
The skew factor in Teradata refers to the imbalance or uneven distribution of data among AMPs in a Teradata system. A high skew factor can negatively impact performance.

5. What are the different types of join strategies in Teradata?
The different join strategies in Teradata include hash join, merge join, nested join, and product join. Each join strategy is used based on the size of the tables being joined and the available resources.

6. What is a Teradata FastLoad utility?
Teradata FastLoad is a high-speed utility used to load large volumes of data into an empty Teradata table. It provides fast, non-logged data loading and is particularly useful for initial data population.

7. What is a Teradata MultiLoad utility?
Teradata MultiLoad is a utility used to load, delete, update, and update tables in Teradata. It can process multiple tables concurrently and supports error logging and recovery.

8. What is a Teradata TPump utility?
Teradata TPump is a utility used to insert, update, or delete records in real-time or near real-time into Teradata tables. It is suitable for applications that require continuous data loading.

9. How is data integrity maintained in Teradata?
Teradata maintains data integrity through the use of referential integrity constraints, primary key constraints, unique constraints, and check constraints. These constraints ensure data consistency and accuracy.

10. What is a Teradata View?
A Teradata View is a virtual table that does not physically store data. It is a predefined SQL query stored in the data dictionary and can be used to simplify complex queries, enhance security, and provide data abstraction.

11. What is Teradata FastExport utility?
Teradata FastExport is a utility used to export large amounts of data from Teradata tables to external files. It supports multiple export formats and parallel data extraction.

12. What is a Teradata group by clause?
The group by clause in Teradata is used to group rows based on one or more columns and perform aggregate functions on each group. It is commonly used with the select statement to produce summary reports.

13. What is a Teradata collect statistics?
Teradata collect statistics is a command used to gather data distribution statistics for one or more columns in a table. It helps the optimizer make informed decisions on query execution plans.

14. What is a Teradata Secondary Index?
A Teradata Secondary Index (SI) is an additional index created on a table to support fast access to non-primary key columns. It allows for quicker data retrieval but may impact write performance.

15. What is a Teradata fallback protection?
Teradata fallback protection is a mechanism that provides data redundancy by storing a duplicate copy of each row on a different AMP. It ensures data availability and reduces the risk of data loss.

16. What is a Teradata Join Index?
A Teradata Join Index is a precomputed and physically stored table that contains columns from multiple base tables. It is used to speed up query performance by pre-joining tables and aggregating data.

17. What is a Teradata partitioned primary index?
A Teradata partitioned primary index (PPI) is a primary index that is divided into multiple partitions based on a partitioning expression. It enables data distribution and retrieval efficiency.

18. What is Teradata Query Banding?
Teradata Query Banding allows you to associate application-specific information, known as query bands, with SQL requests. It helps in workload management, query monitoring, and performance tuning.

19. What is Teradata Viewpoint?
Teradata Viewpoint is a web-based monitoring and management tool for Teradata systems. It provides a graphical interface for system administrators to monitor performance, manage resources, and perform system tasks.

20. What is Teradata TASM?
Teradata TASM (Teradata Active System Management) is a workload management feature that allows administrators to prioritize, optimize, and control system resources based on business needs and service-level agreements.

These are some of the basic Teradata interview questions and answers that can help you prepare for a Teradata interview.

1. What are the main components of Teradata Architecture?
Teradata consists of Parsing Engine, BYNET, Access Module Processors (AMPs), Virtual Processors (VPROCs), and Disk Drives.

2. Explain the purpose of Parsing Engine in Teradata.
The Parsing Engine is responsible for receiving and interpreting SQL queries, creating execution plans, and optimizing query performance.

3. What is BYNET in Teradata?
BYNET is a high-speed interconnect network that enables communication between different components of Teradata architecture.

4. What is a Primary Index in Teradata?
A Primary Index (PI) is defined on a Teradata table to support data distribution across AMPs. It enables fast and efficient access to data within the table.

5. What are the various types of Primary Indexes in Teradata?
The types of Primary Indexes in Teradata are Primary Index (PI), Unique Primary Index (UPI), and Non-Unique Primary Index (NUPI).

6. What is the difference between Primary Index and Secondary Index?
Primary Index is used for data distribution, while Secondary Index is used for faster access to data based on non-primary column values.

7. How do you improve performance in Teradata?
Performance in Teradata can be improved by proper indexing, data distribution, query optimization, and using appropriate joins and aggregations.

8. What is a PPI (Partition Primary Index) in Teradata?
PPI is used for dividing table rows into partitions based on a specified column. It helps in improving query performance by restricting data access to specific partitions.

9. What is the advantage of using MultiLoad in Teradata?
MultiLoad allows fast loading of large volumes of data into Teradata tables. It leverages parallel processing capabilities and supports various loading modes.

10. What is the difference between SET and MULTISET in Teradata?
SET tables do not allow duplicate rows, while MULTISET tables allow duplicate rows.

11. Explain the concept of Join Index in Teradata.
Join Index is a type of materialized view that stores pre-joined data based on specific columns. It improves query performance by eliminating the need for complex joins.

12. What is the purpose of FALLBACK protection in Teradata?
FALLBACK protection is used to provide data redundancy and availability in case of AMP failures. It replicates data on an alternate AMP to ensure data integrity.

13. How does Teradata handle data distribution across AMPs?
Teradata uses a hashing algorithm called the Primary Index Algorithm to distribute data evenly across AMPs based on the values of the Primary Index.

14. What is the purpose of the Dictionary table in Teradata?
The Dictionary table stores metadata information about database objects, data types, access rights, and system configuration in Teradata.

15. What is the difference between FastExport and TPT in Teradata?
FastExport is a utility used for extracting large volumes of data from Teradata tables, while TPT (Teradata Parallel Transporter) is a more advanced and flexible data loading and extraction utility.

16. How can you identify and resolve performance bottlenecks in Teradata?
Performance bottlenecks can be identified by analyzing query execution plans, monitoring system resource utilization, and using profiling and optimization tools. Once identified, they can be resolved by tuning queries, indexes, and data distribution.

17. What is the purpose of the Teradata Multi-System Environment?
The Teradata Multi-System Environment allows multiple Teradata systems to work together and share resources, providing scalability and high availability.

18. How does Teradata handle concurrency control?
Teradata uses a concept called AMP Locking to handle concurrency control. It allows simultaneous access to data by multiple users while ensuring data consistency and integrity.

19. What is the purpose of the Query Band in Teradata?
The Query Band is used to attach metadata to SQL queries for tracking and analysis purposes. It allows users to pass session-specific information with each query.

20. What are the Teradata performance tuning techniques?
Teradata performance tuning techniques include query rewriting, index optimization, data distribution optimization, workload management, statistics collection, and system configuration tuning.