SAP HANA 表之间关联之UNION

• Unions are used to combine the result-set of two or more select statements.
• The Union operation is popular for combine plan and actual values in CO-PA.
• Unions are not supported in modeled artifacts(Attribute views or analytic views) and can only be realized in calculation views.
• refrain from Joining analytical views; rather use Unions with constant values.
• Unions with constant values are supported within Graphical Calculation views and the Union operator can accept 1..N input sources.
• Whereas a script based calculation view’s comparable CE_UNION_ALL function can only accept 2 input sources at a given time.