Teradata is defined as a system-like known for its vast and valuable features that are considered best for several tasks related to the data. It is a database management system which is relational. Teradata has several benefits. It has many heterogeneous destinations, component reusability is not limited, debugging in Teradata is relatively straightforward. Naturally, the popularity of Teradata is on the rise. That’s why learning about frequently asked Teradata interview questions will undoubtedly prove helpful. This article offers sample answers to carefully identified Teradata interview questions. Several Teradata interview questions, including analyst interview questions, are provided below for your aid.
Basic Teradata interview questions and answers
1. Teradata interview questions begin with asking us about Teradata
Show the interviewer that you have a thorough knowledge of Teradata so that you can use it effectively. Try to show your practical knowledge of the system. So you might tell in the interview that Teradata is a relational database management system offered by Teradata Corporation. Further, it behaves like a server and can be scaled to suit different data handling requirements. It is compatible with the American National Standards Institute, can run on single or multi nodes and is an open system. It has features that are reliable and can be used for different projects.
2. Further Teradata interview questions may include – what are the features of Teradata?
Teradata manages a large volume of data without facing any glitch
The factors that can impact its important parameters are minimal
Despite unstructured segments, the data can easily be managed
A lot of helpful information can be derived from the tasks that can be performed while data is collected with Teradata
Teradata approach has wide adaptability and scalability
To obtain accurate results, tasks can be divided amongst teams
It can manage bulk data in the shortest possible time
RDMS can be made superior in every respect through Teradata
3. Further Teradata interview questions are Where is password stored in Teradata?
It can be viewed using DBC.DBASE however it will be in encrypted format.
4. Teradata interview questions ask about the table types supported by Teradata
It is a specific method to store data and it is essential to understand different types to use the system. There are four table types –
- Permanent Table
- Derived Table
- Volatile Table and
- Global Temporary Table
Each type has different purpose of use. E.g., Permanent Table is the default type and used to store unchanging data. It is used during execution queries. Derived table holds intermediate data results. The Volatile table is used for data storage during data sharing, transmission or complex calculations. This too holds intermediate data. And Global Temporary Table stores data values that are used in applications and deleted this data after each session.
5. How to determine the size of table in Teradata?
DBC.TABLESIZE view can be used in Teradata to check the storage space used by a table.
6. What are some of the principal benefits of using Teradata?
Here the interviewer wants to assess how Teradata is unique and how efficiently and confidently you can use them. So name four to five significant advantages of using the software. You may include its load distribution functionality, ANSI compatibility, and scalability while answering. Teradata is a very efficient framework due to its load distribution functionality and superior performance, which is again because of many processors. Further, it’s completely scalable so that it can be tailored according to the need of the particular project. It is compatible with the ANSI. Therefore it’s a standardized service. It can execute multiple complex queries simultaneously and can be used with various computer operating systems. That’s why it’s a preferred RDBMS for extensive, complex data storage processes.
7. Teradata interview questions definitely ask about Teradata architecture?
Teradata has several useful components and users are free to get the desired outcome in the shortest possible time. A few widely used components are listed below that play a significant role in making the task simple –
- Parsing Engine
- Virtual Disk
- Access Module Processor
- Bynet
- Virtual Storage System
- Meta Manager
- In Teradata what exactly is an Access Module Processor?
It is a virtual processor responsible for managing and controlling a single segment of database. It is not possible by any other access module processor to share the same. Thus, it is also called a secure or share-nothing architecture.
8. What is Parsing Engine in Teradata?
Parsing Engine is an approach that is responsible for enabling the users to handle all the SQL requests and then provide responses in the SQL. Several software components are present in it and the users are free to split the SQL into different sections. These sections are then transferred to AMP in a defined or in random manner.
9. Describe a Node and a Message Passing Layer?
A thorough knowledge of Teradata architecture can separate an average candidate from an ideal one. Showing the interviewer a good grasp over these components will certainly help you stand out. Answer this question by specifying how each component functions in the system.
A Node is the system’s basic unit and a single server in the system. Each Node has a Teradata RDBMS, operating system, disk space and CPU.
The message passing layer is used by the Parsing Engine, Nodes and Access Module to communicate. Inside the system the component is called networking layer.
10. Name a unique feature that you only find in Teradata and not any other RDBMS?
There is a command known as ‘Update else Insert’ (USERT) which is available only in Teradata.
11. What is the biggest issue in Teradata and how can it be avoided simply?
The failure of the Node is one of the significant problems in Teradata. Although the chances are less, it creates several glitches when they happen. There is a dedicated feature in Teradata to control the situation, and that is creating a Clique. The same is an assortment of nodes that are shared between the shared drives. When this approach is considered, the failure of one Node doesn’t make much impact.
Below are given some Teradata SSRS Interview Questions.
1. How to check SQL history in Teradata?
In Teradata DBC.QRYLOG can be used to view SQL history. Also in most Teradata prod environment DBA will have backup database which will store entire history. This database is generally named PDCRINFO.
2. Teradata interview questions further include What are the different types of Teradata utilities?
Various utilities are available in Teradata and these are –
- Batch Teradata Query
- FAST EXPORT
- FAST LOAD
- MULTI LOAD
3. What is FAST EXPORT in Teradata?
In Teradata FAST EXPORT refers to export data from Teradata to a Flat file.
4. Teradata interview questions can ask about FAST LOAD in Teradata
In Teradata this option loads a massive amount of data into EMPTY tables.
5. What are some different methods of releasing the FASTLOAD on the table?
Execute the fast load script by removing the DML block, i.e., only BEGIN LOADING and END LOADING in the fast load script should be kept. Another method is to drop the table and create it again. As FASTLOAD works on an empty table, dropping, making should not end in data loss.
6. Teradata interview questions include is there a way to duplicate data?
No, it cannot be done. FASTLOAD is a property to discard the duplicate records. Upon restarting FASTLOAD sends data back from last checkpoint. In that case it may send some data again. Hence, FASTLOAD identifies such records as duplicate and discard it.
7. Teradata interview questions further ask How many populated tables does Teradata MultiLoad support?
It supports upto five populated tables.
8. How many phases are in MultiLoad?
Multiload has five phases namely Preliminary Phase, DML Transaction Phase, Acquisition Phase, Application Phase, Clean-up Phase.
9. In Teradata interview questions, What is transient journaling in Teradata is an important question?
The transient Journal is a system-maintained dictionary table that provides a way to protect transactions from various system failures and from deadlock (see SQL Request and Transaction Processing for a description of the draw). Each transaction processed by the Teradata database records a before-change image of rows touched by the trade.
Then if a transaction fails for some reason, the before change image of any modified rows can be retrieved from the short journal and written over the modifications, returning the row to the same state it was in before the transaction occurred. Teradata Database removes all before change images from the short journal after a transaction commits.
10. Teradata interview questions may ask what are Database Privileges in Teradata?
A database privilege is permission to access or to manipulate a database object or data. Specific requests are required for nearly everything that can be done in the Teradata Database.
Teradata Database privileges are used by administrators to control access to database objects and data and to control the types of actions and activities available to users.
11. In Teradata interview questions it’s frequently asked What are the privilege levels available in Teradata?
Teradata Database supports system level, object level, row level and zone level privileges.
- System level privileges
- Object level privileges
- Database
- Table
- Row or column
- Other object types
- Row level privileges
- Zone level privileges
12. Part of Teradata interview questions may be explaining the GIVE statement in Teradata
GIVE statements transfer ownership of database or user space to another user. It also moves all databases and users owned by the shared database or user.
13. Teradata interview questions What is GRANT statement in Teradata is asked frequently?
Grant establishes explicit privileges for one or more users, proxy users, databases or roles.
In Teradata different GRANT forms are there and these are –
- GRANT (Monitor form): Performance monitoring of Teradata database
- GRANT (Role form): Granting role membership to users and other roles
- GRANT (SQL Form): Granting access to, creation of, or logging off various Teradata database objects.
- GRANT ZONE: Granting zone guest status to users or roles that do not belong to any zone. Zone users must grant privileges to zone guests before access is permitted.
- GRANT CONNECT THROUGH: Granting the ability to connect as a proxy permanent or proxy application user through a trusted user.
- GRANT LOGON: Granting system logon privileges.
14. Teradata interview questions also include What is REVOKE statement in Teradata ?
It rescinds explicit privileges. The privileges might have been conferred automatically or by a GRANT statement.
So further Teradata interview questions based on performance tuning are –
It rescinds explicit privileges. The privileges might have been conferred automatically or by a GRANT statement.
So further Teradata interview questions based on performance tuning are –
15. In Teradata interview questions What are some of the advantages of Teradata may be asked
There are several advantages of using a Teradata database and these are –
- Larger warehouses – this database management system supports huge warehouse data than all its competitors in the market.
- Sacalability – in this database we can store from 100 GB to over 100+ petabytes of data on a single system. This huge amount of data can be scale without affecting any performance-related issues.
- Parallel Aware Optimizer – it makes query tuning and simplifies query running
- It supports Concurrent Users – Teradata can handle various complex queries often run by users simultaneously.
- Parallel Architecture – it runs on parallel architecture to support unconditional parallelism.
- Supports Ad Hoc Queries – Teradata built with ad hoc SQL queries to support a particular purpose. This helps in increasing productivity of developers.
- Teradata manager – it is a central place to control the database.
- Teradata lowest total cost – Teradata is the only vendor that provides lowest total cost of its ownership.
- Fault tolerance – in Teradata fault tolerance is a built-in feature. Because of this feature data availability is very high and the failure ratio is less.
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Further Teradata interview questions for your benefit would be :
1. How many ways Teradata Database can be used?
It can be used in various ways such as enterprise data warehousing, active data warehousing, CRM, Ebusiness, Datamarts.
2. What are some main components of Teradata architecture?
Main components of Teradata architecture are Parsing Engine, Access Module Processors, Bynets, Disks.
3. Tell us about BYNET and its purpose?
It os the main component of the architecture and acts as message passing layer.
4. What is Unique Primary Index (UPI) in Teradata?
As the name suggests it is unique and cannot have any duplicates. If a row that is already in the table is inserted using primary index value, it will be rejected. A upi enforces uniqueness of a column.
5. What is Non-Unique Primary Index (NUPI) in Teradata?
It means that the values for selected column can be non-unique. Duplicate values can exist.
6. How to create an NUPI in Teradata?
CREATE TABLE sample_2
(col_x INT
,col_y INT
,col-z INT)
PRIMARY INDEX (col_x);
7. What is a columnar in Teradata?
Its main purpose is to spread the rows evenly across AMP’s
8. Write a columnar example code?
CREATE Table Employee
(
Emp_Id Integer
No Primary Index
PARTITION BY COLUMN
9. Explain about the locks in Teradata?
This feature prevents multiple users to access same data at the same time.
10. Tell us about the types of locks
There are four types of locks in Teradata
Exclusive lock
Write lock
Read lock
Access lock
11. What is RAID in Teradata?
RAID stands for Redundant Array of Inexpensive Disks. It’s a storage technology that provides data protection at disk drive level.
12. What are cliques in Teradata?
It’s a group of nodes that share access to the same disk arrays.
13. Define Primary Index and how is it different from Primary Key?
| Primary Key | Primary Index |
| Cannot be NULL | Can be NULL |
| Not manadatory | Mandatory with exception of NOPI tables |
| Does not help in data distribution | Helps in data distribution |
| Should be unique | Can be UNIQUE (Unique Primary Index) or NON_UNIQUE (primary index/ NUPI) |
| Logical implementation | Physical implementation |
14. How does teradata distribute rows in AMP’s?
ROWHASH and PRIMARY INDEX column are used to determine which AMP should store what part of data.
15. What is default session transaction mode in Teradata?
BTET is the default session mode
16. Tell us about Multi Statement Request (MSR) in Teradata?
MSR is used to insert data into table by treating several INSERT blocks as one transaction.
17. Explain how to skip five rows while reading data from file using Teradata utilities?
SKIP command can be used in BTEQ, RECORD command can be used to specify from which record Teradata should start reading data from file.
18. How many join strategies are available in Teradata?
Five. Merge, Nested, Hash, Product, Exclusion
19. How to find teradata release and version details?
SELCT*FROM DBC.DBCINFO
20. Name three result code variables in Stored Procedures.
SQLSTATE, SQLCODE, ACTIVITY_COUNT
21. What is the default value for any three result code variables?
SQLSTATE ‘00000’
SQLCODE: 0
ACTIVITY_COUNT: 0
22. What SQL Security options available in stored procedures in Teradata?
SQL SECURITY OWNER/ CREATOR/ DEFINER/ INVOKER
23. What are the connectivity options available for TSA?
ODBC and Teradata.net
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