Indexing, Index Search, and Table Crawl

Question

I have the following table:

Create table Tab_with_Ix
(
    id int not null,
    name nvarchar(10),
    phone decimal(10,0)
)

I inserted a few entries:

insert into Tab_with_Ix 
values(1, 'Yogesh', 8855664452), (2, 'Vinay', 9977884455), (3, 'Sam', 9988554466)

Now I am creating a non-clustered index on Tab_with_Ix:

CREATE NONCLUSTERED INDEX NCI_Ix on Tab_with_Ix(id)

Now when I request Tab_with_Ix:

Select * 
from Tab_with_Ix
where id = 1

I get the execution plan as:

But when I use the following query:

Select id 
from Tab_with_Ix 
where id = 1

I get the execution plan as:

My question is: why does SQL Server use a table scan once and another time the index searches?

Answer 1

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