Interview Questions.

Q1. While Creating Table My Dba Has Fallback Or No Fallback In His Ddl. What Is That?

FALLBACK requests that a 2nd copy of each row inserted into a table be stored on every other AMP within the equal cluster. This is completed while AMP goes down or disk fails.

Q2. What Is Basic Teradata Query Language?

It lets in us to write down SQL statements together with BTEQ commands. We can use BTEQ for uploading, exporting and reporting purposes.

The instructions begin with a (.) dot and can be terminated by means of the usage of (;), it isn't always obligatory to apply (;).

BTEQ will count on any factor written with out a dot as a SQL assertion and requires a (;) to terminate it.

Q3. Did You Write Stored Procedures In Teradata?

No, due to the fact they emerge as a unmarried amp operation and my organization didn’t encourage that.

Q4. What Is A Three-tier Data Warehouse?

The 3-tier differs from the two-tier structure by way of strictly enforcing a logical separation of the graphical user interface, business good judgment, and records. The 3-tier is extensively used for facts warehousing nowadays. Organizations that require more performance and scalability, the three-tier architecture may be greater suitable. In this structure, records extracted from legacy systems is cleansed, transformed, and stored in excessive –pace database servers, which might be used as the target database for front-cease records get admission to.

Q5. What Is Data Mart?

A information mart is a unique cause subset of employer information used by a particular department, feature or utility. Data marts may also have each precis and information data, however, normally the data has been pre aggregated or transformed in some manner to higher cope with the specific kind of requests of a particular person community. Data marts are categorised as unbiased, logical and dependant facts marts.

Q6. What Is Ods?

An operational statistics store (ODS) is primarily a “unload” of applicable facts from a totally small range of systems (often just one) commonly with very little transformation. The blessings are an ad hoc query database, which does not affect the operation of structures required to run the enterprise. ODS’s usually deal with records “raw” and “present day” and might answer a restrained set of queries as a result.

Q7. What Is Real Time And Near Real Time Data Warehousing?

The distinction among real time and close to actual time may be summed up in one word: latency. Latency is the time lag that is between an hobby crowning glory and the completed hobby facts being to be had in the data warehouse. In real time, the latency is negligible whereas in near real time the latency is a tangible time body which include two hours.

Q8. Does Sdlc Changes When You Use Teradata Instead Of Oracle?

If the teradata goes to be most effective a records base method It received’t exchange the System improvement existence cycle (SDLC).

If you are going to use the teradata utilities then it will exchange the Architecture or SDLC.

If your schema is going to be in 3NF then there received’t be massive in exchange.

Q9. How Do You Determine The Number Of Sessions?

Teradata performance and workload.

Client platform kind, overall performance and workload.

Channel overall performance for channel connected structures.

Network topology and performance for network attached structures.

Volume of statistics to be processed by the application.

Q10. Syntax For Case When Statement?

CASE value_expression_1 WHEN value_expression_n THEN scalar_expression_n

END;

Q11. How Do You Create A Table With An Existing Structure Of Another Table With Data And With No Data?

Create table Customerdummy as Customer with statistics / with no facts

Q12. There Is A Column With Date In It. If I Want To Get Just Month How It Can Be Done? Can I Use Sub String?

Sub string is used with char fields. So it can not be used. To extract month from a date column, ex select extract (month from ). Same factor for yr or day. Or hour or mins if it’s a time stamp (select extract (minute from column call).

Q13. What Is Real Time Data Warehousing?

Real-time information warehousing is a combination of  things:

actual-time activity and

data warehousing.

Real-time hobby is activity this is taking place right now. The hobby could be some thing along with the sale of widgets. Once the activity is entire, there may be statistics about it. Data warehousing captures commercial enterprise pastime information. Real-time information warehousing captures business pastime data as it occurs. As quickly as the enterprise hobby is whole and there is records about it, the completed activity facts flows into the information warehouse and turns into available right away. In other words, actual-time records warehousing is a framework for deriving records from records because the information turns into available.

Q14. What Is Data Mining?

Analyzing of big volumes of pretty easy statistics to extract vital tendencies and new, better level records. For instance, a facts-mining application might analyze millions of product orders to determine traits among top-spending clients, which includes their chance to buy again, or their probability to exchange to a one of a kind dealer. 

Q15. What Is Oltp?

OLTP stands for Online Transaction Processing. OLTP makes use of normalized tables to quick document big amounts of transactions whilst making sure that those updates of data occur in as few places as possible. Consequently OLTP database are designed for recording the each day operations and transactions of a enterprise. E.G. A timecard machine that helps a big manufacturing surroundings ought to document efficiently a big number of updates all through critical periods like lunch hour, breaks, startup and close of work.

Q16. Differentiate Database Data And Data Warehouse Data?

Data in a Database is Detailed or Transactional, Both Readable and Write capable and present day.

Data in records warehouse is detailed and summarized, storage location for ancient statistics.

Q17. How To Find Duplicates In A Table?

Group through the ones fields and choose identity, rely(*) from desk institution with the aid of identity having remember (*) > 1.

Q18. What Is Meant By Teradata Gateway?

Just like channel motive force, Teradata Gateway acts as a medium of communication among the Parse Engine and applications that are attached to network customers. Only one Gateway is assigned per node.

Q19. Steps To Create A Data Model?

Get enterprise requirements.

Create High Level Conceptual Data Model.

Create Logical Data Model.

Select goal DBMS in which information-modeling tool creates the physical schema.

Create fashionable abbreviation report in step with enterprise fashionable.

Q20. What Is The Opening Step In Basic Teradata Query Script?

Logon tdipid/username, password.