Teradata Interview questions

1. What is the difference between TD and RDBMS?and what are the features of the TD?2. Briefly explain the TD architecture?3. Explain the Parse Engine architecture?4. What is the difference between database and user?5. How can we protect the data in TD database?6. what are the features of the Bynet? and difference between the symmetrical multiple process and massively parallel process?7. What is the difference between Raid1 and Raid5?8. What is the Primary Index? and what is the difference between Primary index and Primary key?9. How the primary index effect on the data distribution with example?10, What are the features of the Secondary Index and How can data will be stored in the AMP?11. What type of Utilities are using in your project? And tell me important commands and key words?12. Explain Export and import in Bteq? And write import and export examples?13. What is the difference between the Bteq and Fload?14. What is the Error handling? How can we handle the errors in Bteq?15. Types of error tables in fload?16. Explain the advantages and disadvantages of mload and difference b/n normal delete and mload delete?17, Types of tables in mload and locks? 18. Give the example of mload and how can we handle the error handling mload?19. Briefly explain the Tpump and mload?20. What is the fastexport?21. Explain coalesce, cast, as clause ,substr, and rank with examples?22. How can we solve the performance tunining to solve the specified query (Explain, Collect statistics with example?)?23. Explain global, volatile, derived tables, and what are the differences b/n them?24. Explain the join strategic?25. What are the difference b/n memories (SPOOL, Permanent and Temporary )?26. Why we are using diagnostics and what is the use?27. Explain the Join and Hash Index?28. Explain the Hash AMP,Hash Back AMP, Hash bucket and Hash map?

Interview sql queries(13q)

1)To find out the duplicate rows from the emp table?

Sql>select empno,count(*)from emp Group by empno having in count(*)>1;

2)Remove the duplicate values from the emp table?

Sql>delete from emp where rowid not in (select max(rowid) from emp group by deptno);

3)To find out the rank of the employe based on salarye?

Sql>select eno,ename,sal,r from(select eno,ename,sal,rank() over(order by sal desc) r from emp);

4) To find out the “top 5” rank of the employe based on salarye?Sql>select *from (select *from emp order by sal desc) where r<=5;

5)How to find , we have same salarye employe got the same rank(by using dens_rank())? Sql>select eno,ename,sal,r from (select eno,ename,sal,dens_rank()over(order by sal desc) r from emp) where r<=5;

6)selct the alternative rows in a table?Sql>select *from emp where(rowed,0) in (select rowid,mod(rownum,2) from emp);

7)Waq to display all employe detalies who has working manager to other employee?Sql>select *from emp where empno in (select distinct mgr from emp);

8) waq to display all employe detalies who has not working manager to other employee?Sql>select *from emp where empno in (select empno from emp minus select distinct mgr from emp);

9)what is the exists command where we can use?Sql>select dname from dept where exists (select *from emp) where dept.deptno=emp.deptno;

10) To display the empno,departno,and max salary of each department?Sql> select a.empno,a.departno,b.sal,b.departno from emp a (select max(sal),departno from emp group by departno ) b Where a.sal=b.sal and a.departno=b.departno;11) Based on the birthday date to find out the age of the employee?Sql> select ename, turnc(months_between(sysdate,birthday)/2 ) “age” from emp;

12) To find out the second heights salary of employee from employee table? Sql> select * from emp Where sal in (select max(sal) from empWhere sal not in(select max(sal) from emp));

13) To find out the ovals in the name?Sql> select length(ename)-length(translate(lower(ename),’TAEIOU’,’T’)) from emp;

10) difference b/w the functions&storedprocedures?Ans>To see the DWH material

11)diff b/w the rowid&rownum?Ans>To see the DWH material

12)diff b/w the view&materialized view?Sql> Ans>To see the DWH material

13)what is the use of the joins? How many types give each and every exampules?Ans>To see the DWH material

14) What is the difference bn Union and Union all?

15) Explain date functions, data conversion functions and trim functions?See the DWH material in that basic DW questions are there, please follow. DWH QUSIONS

1)what is the datawarehouse?2)what is the fetures of DWH?3)what is d/b datamort&dwh?4)what is the schema?how many types what are they?5)what is the fact&dimensional table?6)what is the adit,junk,de _genrated dimensional?example7)what is the types of fact table?example8)what is the conformed dimension&conformed fact?9)Types of SCD IMPLEMENTATIONS?10)what is d/b the ODC&DWH?

Ansers: DWH matirialo vunae

UNIX

Basic commands:

Cat file1 (cat is the command to create none zero byte file)cat file1 file2 > all -----it will combined (it will create file if it doesn’t exit)cat file1 >> file2---it will append to file 2

o > will redirect output from standard out (screen) to file or printer or whatever you like.

o >> Filename will append at the end of a file called filename.

o < will redirect input to a process or command.

How to create zero byte file?Touch filename (touch is the command to create zero byte file)how to find all processes that are runningps -A

crontab file So a create a file with the scheduled jobs as above and then typecrontab filename .This will scheduled the jobs.

Below cmd gives total no of users logged in at this time.who | wc -l

echo "are total number of people logged in at this time."Below cmd will display only directories$ ls -l | grep '^d'Pipes:The pipe symbol "|" is used to direct the output of one command to the input of another.Moving, renaming, and copying files:Cp file1 file2 copy a filemv file1 newname move or rename a filemv file1 ~/AAA/ move file1 into sub-directory AAA in your home directory.rm file1 [file2 ...] remove or delete a fileTo display hidden filesls –a

Viewing and editing files:cat filename Dump a file to the screen in ascii. More file name to view the file contenthead filename Show the first few lines of a file.head -5 filename Show the first 5 lines of a file.tail filename Show the last few lines of a file.Tail -7 filename Show the last 7 lines of a file.

Searching for files : find commandfind -name aaa.txt Finds all the files named aaa.txt in the current directory or any subdirectory tree. Sed (The usual sed command for global string search and replace is this)If you want to replace 'foo' with the string 'bar' globally in a file.$ sed -e 's/foo/bar/g' myfile.txt

find / -name vimrc Find all the files named 'vimrc' anywhere on the system. find /usr/local/games -name "*xpilot*"

Find all files whose names contain the string 'xpilot' which exist within the '/usr/local/games' directory tree.

Imp:AWK,SCP,GREEP command examples