What is the use of index in sql?

0 Answers  

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Create table emp (id number(9), name varchar2(20),salary number(9,2)); The table has 100 records after table created.Now i nee to change id's Datatype is to be Varchar2(15). now Alter table emp modify(id varchar2(15),name varchar2(20), salary number(9,2)); Whether it will work or returns error? post answer with explanation.

13 Answers   Oracle, TCS,

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What is the difference between union and union all command?

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What is an index? What are the types of indexes? How many clustered indexes can be created on a table?

0 Answers  

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what are the limitations of identity column? : Transact sql

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How will you select unique values from a list of records?

7 Answers   Cap Gemini,

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Can you join a table to itself?

0 Answers  

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table :- city name country code abc 11 bcd 22 cde 232 def 33 write a procedure , so that when we give a phone no. eg - 1123456789 - o/p sud be city name = abc if phone no. - 2322345897 , o/p sud be =cde note - bcd and cde city name sud be diff. as dey diff only with th last no. Pls ans. this questnion.

1 Answers  

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How will you make performance better for application including front end and back

2 Answers   Metric Stream,

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what is a database lock ? : Sql dba

0 Answers  

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How to count the no of records of a table without using COUNT function?

11 Answers   TCS, Tesco,

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If a cursor is open, how can we find in a pl/sql block?

0 Answers  

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