Latest Teradata Interview Questions and Answers
Define Teradata? Give some of the primary characteristics of the same.
Teradata is basically an RDMS which is used to drive the Datamart, Datawarehouse, OLAP, OLTP, as well as DSS Appliances of the company. Some of the primary characteristics of Teradata are given below.
- Is capable of running on Single-nodes, as well as multi-nodes.
- Parallelism is built into the system.
- Very much compatible with the standards of ANSI.
- Tends to act in the same way as a server.
- It is an Open System that basically executes for UNIX MR-RAS, Suse Linux ETC, WIN2K, etc.
What are the newly developed features of Teradata?
Some of the newly developed features of Teradata are: –
- Automated temporal analytics
- Extension in the compression capabilities which allows flexible compression of data about 20 times more data than the previous version.
- Customer associated innovation like tetradata viewpoint.
Highlight a few of the important components of Teradata.
Some of the important components of Teradata are: –
- Access Module Processor (AMP)
- Parsing Engine (PE)
- Virtual Disk (vDisk)
- Virtual Storage System (VSS)
Mention the procedure via which, we can run Teradata jobs in a UNIX environment.
All you have to do is perform execution in UNIX in the way as mentioned below.
$Sh > BTEQ < [Script Path] > [Logfile Path]
$Sh > BTEQ < [Script Path] TEE [Logfile Path]
In Teradata, how do we Generate Sequence?
In Teradata, we Generate Sequence by making use of Identity Column
During the Display time, how is the sequence generated by Teradata?
All you have to do is use CSUM.
A certain load is being imposed on the table and that too, every hour. The traffic in the morning is relatively low, and that of the night is very high. As per this situation, which is the most advisable utility and how is that utility supposed to be loaded?
The most suggestible utility here has to be Tpump. By making use of packet size decreasing or increasing, the traffic can be easily handled.
If Fast Load Script fails and only the error tables are made available to you, then how will you restart?
There are basically two ways of restarting in this case.
- Making the old file to run – Make sure that you do not completely drop the error tables. Instead, try to rectify the errors that are present in the script or the file and then execute again.
- Running a new file – In this process, the script is executed simply using end loading and beginning statements. This will help in removing the lock that has been put up on the target table and might also remove the given record from the fast-log table. Once this is done, you are free to run the whole script once again.
Mention a few of the ETL tools that come under Teradata.
Some of the ETL tools which are commonly used in Teradata are DataStage, Informatica, SSIS, etc.
Highlight a few of the advantages that ETL tools have over TD.
Some of the advantages that ETL tools have over TD are: –
- Multiple heterogeneous destinations, as well as sources can be operated.
- Debugging process is much easier with the help of ETL tools owing to full-fledged GUI support.
- Components of ETL tools can be easily reused, and as a result, if there is an update to the main server, then all the corresponding applications connected to the server are updated automatically.
- De-pivoting and pivoting can be easily done using ETL tools.
What is the meaning of Caching in Teradata?
Caching is considered as an added advantage of using Teradata as it primarily works with the source which stays in the same order i.e. does not change on a frequent basis. At times, Cache is usually shared amongst applications.
How can we check the version of Teradata that we are using currently?
Just give the command .SHOW VERSION.
Give a justifiable reason why Multi-load supports NUSI instead of USI.
The index sub-table row happens to be on the same Amp in the same way as the data row in NUSI. Thus, each Amp is operated separately and in a parallel manner.
How is MLOAD Client System restarted after execution?
The script has to be submitted manually so that it can easily load the data from the checkpoint that comes last.
How is MLOAD Teradata Server restarted after execution?
The process is basically carried out from the last known checkpoint, and once the data has been carried out after execution of MLOAD script, the server is restarted.
What is meant by a node?
A node basically is termed as an assortment of components of hardware and software. Usually a server is referred to as a node.
Let us say there is a file that consists of 100 records out of which we need to skip the first and the last 20 records. What will the code snippet?
We need to use BTEQ Utility in order to do this task. Skip 20, as well as Repeat 60 will be used in the script.
PDE basically stands for Parallel Data Extension. PDE basically happens to be an interface layer of software present above the operation system and gives the database a chance to operate in a parallel milieu.
What is TPD?
TPD basically stands for Trusted Parallel Database, and it basically works under PDE. Teradata happens to be a database that primarily works under PDE. This is the reason why Teradata is usually referred to as Trusted Parallel or Pure Parallel database.
What is meant by a Channel Driver?
A channel driver is software that acts as a medium of communication between PEs and all the applications that are running on channels which are attached to the clients.