Hello Varaprasad,
Few differences I have seen so far:
1. Input parameters can be created and can be used to set filters on dimensions or used in calculations etc at Node level in a HANA view. They can also be created at the semantic layer, but cannot be used at the semantic level.
Variables can be created only at the semantic level and used at the semantic level as filters to the dimensions exposed to semantic.
Input parameters are used at Node level. Variables act as filters applied on the entire query, similar to Where clause in a Select statement.
2. Input parameters of a view that is consumed in a scripted view in HANA can be set using Placeholder in the Select statement. Variables cannot be set via scripted HANA views.
3. Input parameters can be used in expressions inside Calculated columns and Restricted columns. Variables cannot be used in calculated/restricted columns.
4. If a variable is not set at run-time, the query returns the data without applying any filters.
Thanks,
Nithya V