Answer / Pramila Kumari

NoSQL databases offer several advantages, such as scalability (they can handle large amounts of data and high traffic), flexibility (they support various data models), and performance (they can handle read-heavy and write-heavy workloads efficiently).

Explain the uses of database trigger.

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Does oracle roll back the transaction on an error?

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How do you define a foreign key?

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What is sql exception?

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what is cursor procedure

1 Answers   iGate,

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Is sql similar to python?

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If you have to declare procedure1,procedure2 in package specification and if you have to declare procedure1,procedure2 and procedure3 in package body? is it compilation or not and execute or not? what type of error is given please

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What are the advantages of pl sql over sql?

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What is the difference between row level and statement level trigger?

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how to check the 3rd max salary from an employee table? One of the queries used is as follows: select sal from emp a where 3=(select count(distinct(sal)) from emp b where a.sal<=b.sal). Here in the sub query "select count(distinct(sal)) from emp b where a.sal<=b.sal" or "select count(distinct(sal)) from emp b where a.sal=b.sal" should reveal the same number of rows is in't it? Can any one here please explain me how is this query working perfectly. However, there is another query to get the 3rd highest of salaries of employees that logic I can understand. Pls find the query below. "select min(salary) from emp where salary in(select distinct top 3 salary from emp order by salary desc)" Please explain me how "select sal from emp a where 3=(select count(distinct(sal)) from emp b where a.sal<=b.sal)" works source:http://www.allinterview.com/showanswers/33264.html. Thanks in advance Regards, Karthik.

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What is secondary key?

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what is cross join? : Sql dba

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