The reason I write this “simplest of all blog post” is because of a conversation I had with an interviewee (Mr. X).
Me: What is a SQL Server clustered index?
Mr. X: blah blah…It physically orders a table..blah blah.. It physically orders a table.
Me: Ok. Can you please elaborate?
Mr. X: It physically orders the table… hmmmmm…. Blah blah…
Me: Suppose you have a table with a column having values 1-10. A Clustered index is created on that column as Create index ix_clust on T1 (sno desc). What will be the result of this query…
“Select * from T1”
Mr. X: Very simple – it will return rows from 1-10.
Me: Nice talking to you sir.
Well, below is what actually happens and clustered index physically orders a table .
Having said that, there’s lot more behind the statement “Clustered index physically orders the data in a table” which I will write in a while as I need to go now otherwise my friends will kill me as its TGIF