Unions versus JOINS in SAP HANA

v  Unions are used to combine the result set of two or more SELECT statements.

v  It's always tempting to JOIN two analytic views when measures from more than

v  one table are required. This should, however, be avoided for performance reasons.

v  It is more beneficial to use a Union in a calculation view. Technically, a Union is not

v  a JOIN types.

Points to remember:

v  Union is not supported in the attribute or analytical view but can only be

v  used in calculation views.

v  Union with constant values are supported within graphical calculation views

v  and the Union operator can accept 1...N input sources.

v  Script-based calculation views can only accept two input sources at

v  a given time.

v  Do not JOIN analytical views (to be discussed later), as you might have

v  performance issues. Instead, use Union with constant values when working

v  with multiple fact tables.