Is COUNT(*) indexed?

Question

I want to know just for curiosity that, does Select Count(*) from SomeTableName also traverses all the rows of the database as that of Select * from SomeT

Answer 1

SELECT Count(*)
FROM   SomeTableName 

will always count all rows. Though (unlike SELECT *) it does not have to read all columns and can use the narrowest (non filtered) index available to do so.

Unlike MySQL (MyISAM engine) it does not retrieve the value from metadata.

A rowcount value is available in the metadata and can be retrieved from sys.partitions but this is never used for COUNT queries and isn't always accurate.