SELECT will carry FULL Table scan if the Primary Key attributes are not specified. Behaves like a GetItem otherwise.
SELECT LoginAlias,FirstName, Designation
FROM Employee
WHERE LoginAlias IN ['rajs','johns']
ORDER BY LoginAlias DESC
Example : Using the functions
SELECT *
FROM Employee
WHERE Skill Contains(Skills, 'java')
SELECT FirstName FROM Employee
WHERE begins_with(FirstName,'J')