Calculation view input parameter

Hi all,

i have a problem with an input parameter on calculation view,it has been declared NOT mandatory.

On this calculation view i have created an odata service,so when no filter has to be done the value for my input parameter is '*'.

An example :

   IF '':PCV_SWERK'' <> '*' THEN

     ziig_pdm_swerk = CE_PROJECTION(:ziig_pdm_area,["WPGRP","SWERK","STORT","TPLNR","PLTXT","AUFNR","OBJNR",

     "ZZIIGPOTENE"],'"SWERK" = '':PCV_SWERK''');

   ELSE

     ziig_pdm_swerk = CE_PROJECTION(:ziig_pdm_area,["WPGRP","SWERK","STORT","TPLNR","PLTXT","AUFNR","OBJNR",

     "ZZIIGPOTENE"]);

   END IF;

In this case no data will be fetched because input parameter PCV_WERKS has value '*'. (for this reason i use IF ENDIF statement)

Furthermore,with statement "IF -- ENDIF" performance are really slow.

Someone could you help me,please?

Thanks in advance.

Regards.

Dario.