Parameter and Command Reference > Connector Framework Server Parameters > DRERemoveDuplicates  > IndexOverSocket 

IndexOverSocket 
Enter true when the IDOL server and connector are installed on different computers and documents are indexed over a network. (In this case, DREADDDATA sends data over the network and is slower.)
Enter false when the IDOL server and connector are installed on the same computer and documents are indexed locally. (In this case, DREADD uses file-based indexing and is quicker.)