Similarly a query like '"Jens" OR "Martin" OR "Olsen"' also kill the running time completely.

Indeed it's to be used on a search form where the user can select to search in clients, patients, referals and users (hence the @Client = 1 etc.)

I have removed...

Hi dmoldovan,

Thanks a billion for your suggestions.

Removing the UNIONs did nothing but removing the ORs and replacing them with two SELECT statements is an entirely different case: the execution time...