Index

1. What is Index

https://csharp-video-tutorials.blogspot.com/2013/08/part-35-indexes.html

2. Clustered and non-clustered Index

 Sql server, .net and c# video tutorial: Part 36 - Clustered & NonClustered indexes (csharp-video-tutorials.blogspot.com)






Comments

Post a Comment

Popular posts from this blog

Cursor

Image
  Cursor in SQL Server A cursor in SQL Server is a d atabase object that allows us to retrieve each row at a time and manipulate its data . A cursor is nothing more than a pointer to a row. It's always used in conjunction with a SELECT statement. It is usually a collection of  SQL  logic that loops through a predetermined number of rows one by one. A simple illustration of the cursor is when we have an extensive database of worker's records and want to calculate each worker's salary after deducting taxes and leaves. The  SQL Server   cursor's purpose is to update the data row by row, change it, or perform calculations that are not possible when we retrieve all records at once . It's also useful for performing administrative tasks like SQL Server database backups in sequential order. Cursors are mainly used in the development, DBA, and ETL processes. This article explains everything about SQL Server cursor, such as cursor life cycle, why and when the cursor is us...
Read more

SQL Queries

 --1. Write an SQL query to fetch all the Employees who are also managers from the EmployeeDetails table. --select * from EmployeeDetails e inner join EmployeeDetails m on e.EmpId = m.ManagerId --2. Write an SQL query to fetch duplicate records from EmployeeDetails (without considering the primary key – EmpId). --select *, ROW_NUMBER() over (partition by [FullName], [DateOfJoining], [City] order by FullName) as rownum from EmployeeDetails --select [FullName], [DateOfJoining], [City],count(*) from EmployeeDetails group by [FullName], [DateOfJoining], [City] HAVING COUNT(*) > 1; --3. Write an SQL query to remove duplicates from a table without using a temporary table. --WITH cteRowNum AS  --(select *, ROW_NUMBER() over (partition by [FullName], [DateOfJoining], [City] order by FullName) as rownum from EmployeeDetails) --delete from cteRowNum where rownum >1 --4. Write an SQL query to fetch only odd rows from the table. --WITH cteRowNum AS  --(select *, ROW_NUMBER() ov...
Read more